Army Worms

The Arboretum is under siege! An army has invaded, demanding we relinquish our lawns! Army worms, that is. These pesky creatures can cause major damage, and they unfortunately have a taste for fescue. Last week we came upon a sidewalk full of worms, crawling out of the lawn in search of more food. The grass was a sea of them, their tiny movements making it seem like the ground was alive.

Close up of a fall army worm Spodoptera frugiperda.
Army worms have a distinctive ‘Y’ marking on their heads
and are usually found feeding in groups.

To Spray or Not to Spray

I am always a big advocate of lassez-faire when it comes to controlling insect populations. After all, “plants are meant to be eaten”, right? And every insect has its place in the food web to keep our ecosystem thriving. I say this every time our members call asking about why their coneflowers have holes in the leaves, or why their Zizia has been defoliated. I tell them not to panic, that bugs are good to have in a garden, and that with enough good habitat natural predators will help keep the populations in check.

But when populations explode overnight, it can rightly cause concern. Native perennial flowers have deep tap roots that can reach 10 ft deep and beyond, which means they easily recover from a bit of nibbling. Fescue does not. The root zone is often less than 2ft, and in the heat of summer it can get even shorter. These little bugs can cause big damage! But luckily they rarely kill the grass. According to KSU Extension and Research, they don’t usually eat into the crown of the plant, rather move on to more tender greens. This means the plant can regrow and recover once they leave.

Fall armyworms seldom kill grass ---- rather, than nubbing a plant
down to the crown and growing point, larvae will select a more tender adjacent grass
blade to feed upon. Of course, under heavy feeding pressure, larvae may be forced to
feed deeper down on a plant, but usually, when the food supply becomes scarce or
"tough", the larvae will move "in mass" to adjacent areas where there is a "fresh stand"
of food to feed on.

- Kansas State University Agricultural Experiment Station and Cooperative Extension Service
Army worm damage looks a lot like drought stress at first glance. The grass turns patchy and brown.
This lawn was green and lush 72 hours before this photo was taken, an example of how quickly these little worms can feed.
Fescue at the Dyck Arboretum, beginning to resprout on August 18, 3 to 4 days after the army worms have finished feeding.
Stay tuned for updates in the coming weeks.

Use a Targeted Pesticide

Insecticides containing acephate and spinosad are effective at killing caterpillars, but we opt for friendlier treatments since these are known to harm the bees, birds and butterflies that call the Arboretum home. To avoid unnecessary kill off of non-target insects, I use Bt: Bacillus thuringiensis. This is a biological pesticide that uses bacteria to infect the gut of the army worm. In the alkaline gut environment of insects, it turns toxic and gives them a terminal tummy ache. We also use this around the Arboretum to keep bagworm populations in check when they start to overwhelm our cedar trees. According to current research on Bt, it is non-toxic to humans, pets, birds, and fish. It also has a short life once sprayed, which means reapplication is necessary, but also ensures you aren’t killing more insects than you intended to.

Monoculture Dilema

This is the precisely the problem with monoculture lawns. They require consistent maintenance, chemical and physical, to achieve that uniform, western European ideal of ‘perfection’. As we consider seeding new grassy areas of the Arboretum, we may be looking to a fescue mix, or a seed mix that includes sedges and native grasses together. This means that if an infestation comes along, hopefully not all species in that mix will be palatable and leave some green behind while the rest of the species recover.

If you see a few army worms here and there, don’t panic. Only large populations require a chemical response. But to those of you who will encounter them by the millions this summer like I did, good luck!

Seeded Prairie Checkup

I recently did a seeded prairie checkup to see how our December 2020 sidewalk planting described in the earlier blog post “Seeding After Disturbance” is doing. I’ve been informally monitoring it regularly since spring and have been encouraged by the progress I’ve seen.

Sidewalk edge seeded planting site this week on 8/10/21
The same planting site on the day it was planted 12/28/20 w/ planters Janelle and Kendra

Good Germination

We’ve been lucky with the weather since this planting. Conditions to promote good seed germination have been excellent. Remember the deep freeze we had in February? While it tested our human resiliency and strained our heating bills, it was good for this seeded prairie. Adequate precipitation and freeze/thaw action commenced throughout February and March. These conditions helped work the seed down into the soil while also breaking down their seed coats to help prepare them for germination.

Warmer temperatures along with rains in April and May promoted good germination. Identifiable prairie seedlings from the planted species list identified in the earlier blog post were evident amidst the expected seedlings of annuals like ragweed, sunflower, and foxtail.

Annual sunflower, giant ragweed, and foxtail grass serve as a shading nurse crop for tender, young perennial prairie plants

Thanks to the planting areas’ proximity to a water spigot, I was able to do some supplemental irrigation during the hot, dry weeks of late June and early July to keep the new seedlings from burning up while the seedling roots were small. But periodic rains in July and early August along with mottled shade from the nurse crop of sunflowers and annual grasses provided the conditions needed to help the prairie seedlings get well established as we head into fall.

Species Identified

A brief perusal of seedlings during this week’s seeded prairie checkup helped me find and photograph 14 of the 43 species that were part of the Prairie Moon Nursery seed mix. My prairie seedling identification skills are rusty, but I was able to identify the following seedlings to at least genus and some to species.

Seedlings of these identified species are thick throughout the planting and I’m confident that a good number of the rest of the 43 species in the mix will also show up eventually.

Weed Management

Typical management for a less-manicured seeded planting is simply to mow it a couple of times during the growing season to keep annuals from going to seed. Since such an approach for a higher profile area near the visitor center may look a bit scalped and perhaps not as appealing, we are taking the approach of cutting or pulling stems of the annuals. It is more labor intensive than mowing but not an unmanageable approach for small sidewalk edge planting, and regular volunteer, Gerry Selzer, has cheerfully embraced this task.

This weedy sidewalk edge vegetation is shading and hosting a variety of prairie seedlings underneath
The rare and coveted Gerrius selzeranii

Attracting Insects

One of the main reasons for planting this diverse wildflower seed mix in addition to adding pretty splashes of flower colors, is to attract insects and biological diversity to our sidewalk edge prairie beds. In two or three years, these planted species will be flowering and attracting insects with their flower nectar and host plant vegetation. I look forward to engaging school kids and teachers with regular investigations of these sidewalk edges to learn more about relationship between prairie plants and insects.

A new black-eyed susan is already playing host to caterpillars, possibly of species of checkerspot butterfly

Overall, I’m pleased with the progress of this planting as seen during this seeded prairie checkup. Days are getting shorter and we are almost to the cooler months of this planting’s first year when I can be pretty sure that these young prairie seedlings will have deep enough roots to survive about any weather conditions. Stay tuned for future updates about the development of this planting and consider how you too might add a seeded planting somewhere in your landscape.

Tree Stress

This spring we have several trees showing signs of stress that are not particularly attractive.  Since last fall, something has happened to them.  They leafed out late and/or they have some dead branches throughout the tree.  More than likely, it is a result of the historic cold temperatures this winter.  But it made me wonder about some other reasons these trees may be stressed this spring. 

Why trees?

Trees in Kansas are a luxury and one of your property’s greatest assets. To sit under a mature tree on a warm afternoon, enjoy the blue skies and sip your favorite cool drink is a special experience.

Trees need to withstand the rigors of the climate. Trees block harsh winter winds, give you privacy, delineate boundaries, offer great fall color, attract birds and other wildlife that enhance your enjoyment or your landscape, and increase its resale value. Trees are important for all of these reasons and more, but they are not invincible. At any moment, signs of stress can emerge, so we need to understand and make every effort to alleviate problems that may arise. 

Open-grown burr oaks are wider than they are tall (Photo by Lamar Roth)

Tree Stress Symptoms

Stressed trees are easy to pick out in the landscape. Symptoms will manifest in a number of ways including flaking bark, secretions, distorted or missing growth, insects, foliage issues, dead branches and lack of vigor. 

These symptoms are visual clues to internal, external or environmental stressors. Left untreated, these stressors could ultimately kill your tree. Stressed trees are beacons to insects because they are weaker and vulnerable to attack.  Compounding factors over a number of years from the same stressors or multiple stressors lead to tree fatality. Here are some common causes of stress in trees. 

Poor Tree Watering Techniques  

It is true that trees need water to survive, but they need just the right amount of water.  Too much or too little can cause a tree to be under stress. These problems can be compounded when planted in our clay soils. Defoliation, yellowing of the leaves and branch die back are all symptoms to avoid. Most trees, if properly situated, can withstand seasons of drought without much extra inputs. 

Monitor trees during stressful times such as drought to make sure they don’t need a deep soaking. Keep in mind that waterlogged soils are more problematic than drier soils because proper air exchange by the roots in hindered by extremely wet conditions. Sometimes we see a tree under stress from drought and do more damage by giving it too much water. Give it a deep soaking, but let it dry out between watering.   

Install the tree properly 

One of the first lessons I learned as a novice horticulturist is how to plant a tree. “How hard can it be?”, you may say.  Just dig a hole, put it into the ground, water it for a while and watch it grow. More trees are killed by improper installation than you might realize. Choosing the right tree for the soil conditions, along with understanding mature size, will go a long way to helping that tree survive and thrive. 

In our clay soils, I plant the root flair a few inches higher than the soil line in a hole that is at least twice the size of the root ball. I make a small basin around the tree that makes it easier to water and then lightly mulch the basin. It is important to keep mulch away from the trunk of the tree. I stake the tree for the first year and remember to remove the wires that will eventually girdle the tree if forgotten.

For some additional tips on how to properly plant trees, check out my blog post “Steps to Planting a Tree”.

Beware Lawn mowers and Weed eaters

Anything you can do to keep mowers and weed eaters away from the trunk of trees is vitally important. I have seen too many tree trunks damaged by mowers bumping them and people string trimming around the base of the tree, trying to cut down every sprig of grass. A small two to three foot mulch ring provides just the right buffer between the trunk and lawn.  I have seen a string trimmer completely girdle the soft bark of a maple tree and kill it in a couple weeks. If you have invested in a tree, protect it from these tree killers.   

Mulch Around Trees Properly

The advantages of mulch around trees are obvious. It is one of the easiest things to do and it improves the aesthetics of the landscape. However, too much mulch, mulch touching the trunk, or mulch volcanos around your trees could cause major tree stress. These stressors are totally avoidable with one to two inches of mulch around the trunk, but not touching the trunk. It is important to keep the mulch several inches away from the trunk. Too much mulch will cake up and seal off the soil, impeding proper air exchange by the roots.    

Too much mulch piled up at the base of the tree can lead to fungus, rot, low oxygen levels and tree death.
This is an example of a mulch volcano. Be sure to pull mulch away from trunk of tree and spread out.

Improper Tree Pruning

Pruning your trees as they mature is a necessary function. I generally prune our deciduous trees during the winter when they are dormant, making sure not to remove more than 1/3 of the growth at a time. Proper timing will allow the tree to begin to heal without opening up the tree to potential diseases and pests. Evergreen trees can be pruned any time but I avoid the hottest part of the year.   

Construction Injuries to Trees 

Trees often suffer during and after construction projects. Compacted soils and branch or trunk damage can stunt the growth for several years after the project has been completed.  It often takes years for compact soils to improve.  I killed several nice maple trees after our Visitor Center was constructed because the soil was too compacted.  The soil would not drain and they were essentially planted into an undraining bowl.  The roots were completely surrounded by water and they drowned and stunk when I pulled the dead trees out.  Remember to protect/ fence off any trees you want to save during a construction project. 

Environmental Injuries

There are so many nice trees and shrubs from which to choose. We often push the hardiness zones to grow trees that are borderline hardy in our area. As I mentioned earlier, we have a sawtooth oak and gingko that suffered damage from the extreme cold earlier this year. The are coming out of it, but they will look tough for a few years. These trees are not native and remind me to choose native plants first. It also reminds me to be aware of the hardiness of plants we install. Match plants up to your site, including sun, soil, exposure, hardiness, mature size, and moisture.

Sawtooth Oak winter damage

Trees are resilient, but we can help them by considering their needs. A little homework before planting can alleviate problems through the years. Trees are alive and ultimately affected by so many factors, some of which are out of our control. Who know what the next pest will be? Who knows when the next drought will occur? All we can do is try to create/match an environment conducive to growth.

Buffalograss Seeding Experiment Update

Last November, I set out to establish buffalograss a different way than I have traditionally done. Normally, I have areas prepared this time of year for buffalograss seeding. May and June are considered the best time to plant buffalograss because it is a native warm season grass.  It needs to be planted when soil temperatures are above 60 degrees.

In South central Kansas, it is recommended that seeding of buffalograss be completed no later than August 15. Later seeding is not very successful because the newly germinated seedlings do not get fully rooted before winter. That has been a good rule of thumb, but requires so much water in the summer to get the seeds to germinate.

With this new approach, one plants the buffalograss seeds along with annual ryegrass in the fall or early winter. In theory, the annual ryegrass, a cool season grass, will germinate and hold the soil through the winter. The buffalograss seeds will work their way into the soil with the natural freeze/thaw of the soil throughout the winter. These seeds will then germinate the following spring on their own with annual rainfall and warm 60 degree soil temperature. 

Area before planting, November 2020
Annual ryegrass mowed for the second time this spring.

Update

The buffalograss is starting to germinate. I have not irrigated it this spring, which is a huge time and money saver.   Over the next few weeks, I will monitor it for dryness. Beneficial and timely rains have allowed the seed to germinate on its own. Essentially, this process mimics the natural seeding process. 

In the center of the image, is a buffalograss seedling.

We are mowing the annual ryegrass weekly.  It is important to keep the canopy open so the sun warms the soil, allowing the buffalograss seeds to continue to germinate. The seeded annual ryegrass will expire on its own as we move into warmer summer temperatures. As the ryegrass dies, the roots continue to hold the soil. Buffalograss will then be able to spread and fill in the area through the rest of the summer.

What I would do differently

  • Reduce the seeding rate of the annual ryegrass: It is recommended that you plant 3-4 lbs./1000 sq. ft. I would only seed 2-3 lbs./1000 sq. ft. The seeds will still germinate to hold the soil through the winter, but not be so dense that they shade out the buffalograss seeds in the spring. 
  • Plant buffalograss seed first and slightly cover it: I had some buffalograss seed float off the soil as I established the annual ryegrass seed last fall. 
  • Start the process earlier in the fall after the first freeze (October 15):  It would have been better to get the annual ryegrass established with slightly warmer temperatures, but not so warm that the buffalograss seed germinates. 

I will continue to monitor the progress of the buffalograss planting.  For smaller areas this seems to be a viable alternative to the traditional buffalograss planting. There are additional costs with the purchase of the annual ryegrass seed, but you save so much time and water compared to the traditional seeding method. Look for another update on the buffalograss seeding in a couple of months as the buffalograss begins to spread.     

Weed Profile: Dame’s Rocket

As stewards of our landscapes, we need to be constantly vigilant as we monitor for problematic weeds and invasive species.  We have some usual culprits such as bindweed, bermuda grass, Johnson grass and Bradford pear trees.  However, I have noticed another subtle spreader that is quite attractive but quite pushy – Dame’s rocket. 

For years, I have been monitoring a growing population of Dame’s rocket in one of our bordering hedgerows.  It is beautiful right now with its bright purple blooms, but don’t be fooled. This desirable plant will wreak havoc on the natural environment if left unchecked.  Larger populations will even threaten the survival of native plants and degrade habitat and water quality.

Dame’s Rocket in full bloom

Dame’s rocket (Hesperis matronalis) is a tall, annual, biennial or short-lived perennial, which produces either white, pink or purple flowers in the April and May. It was introduced to North America in the 1600’s from Eurasia. The attractive blooms have made it a garden favorite. It is often seen in roadside ditches, hedgerows, older farmsteads. However, in recent years, Dame’s rocket has gone rogue, moving from yards and garden plantings into adjoining landscapes.

Phlox’s Doppelgänger

From the Mustard family (Brassicaceae), this weed resembles tall garden phlox in height and color. However, Phlox is in the Phlox family (Polemoniaceae). Perhaps the most distinguishing difference between the two is that Dame’s rocket has four petals, while phlox has five. As part of the mustard family, it produces an abundance of seed. These seeds are dispersed by mammals and eaten by birds. When the seed pods ripen, they shoot seed in all directions, including the coats of wildlife. These mammals unknowingly spread the seed to nearby waterways, hedgerows, pond edges, and maybe your landscape. Dame’s rocket is reported in most states equal or north of Kansas longitudinally. It is reported as invasive in CO, CT, IN, MD, MI, NJ, PA, TN, VA, WI, and WV.

Dame’s rocket spreading from it’s original colony

Dame’s Rocket is closely related to other problematic weeds of the mustard, family such as garlic mustard, hedge mustard, wild radish and yellow rocket. All of these weeds are prolific and opportunistic, infesting field margins, woodlands, open grassland and wetlands.  It appears to have allelopathic tendencies (the ability to produce chemicals that prevent or reduce the growth of other plants) similar to garlic mustard. With these tendencies, Dame’s rocket and garlic mustard will quickly form dense monocultures within a few years, pushing out other desirable native plants.  As has happened to our little planting, it quickly colonizes by spreading in every direction. 

Garlic Mustard

Controlling Dame’s Rocket

To control Dame’s rocket, pulling before it produces seed is the best option if the population isn’t too large.  Make sure to remove the whole plant roots and all. Discard the plants in the trash. 

Spraying is another option with a 2,4-D product. A systemic herbicide applied as a foliar spray can be effective. Herbicide is best applied to the basal rosettes (low round clumps of leaves) in late fall or early spring, when other plants are dormant. Always read and follow the directions on the label when using herbicide. Any plan must also be mindful of desirable native plant species and habitat conditions in a targeted location that may be vulnerable to herbicide uses. This is a reason to spray as a last resort. Cutting or mowing can also prevent seed production and spread until other management techniques can be initiated.   

Over the past few years, I have changed my tune regarding Dame’s rocket. As beautiful as Dame’s rocket may appear, it is an invasive species with the potential to damage entire natural ecosystems. I used to say, it is doing no harm growing in the hedgerows. Those are just waste areas that need a little beautification, I thought. Then I started seeing it in other small populations away from the original colony.  Be on the lookout for it and take action before it spreads and really becomes a problem in your landscape or your neighbors landscape.

Monarch Fallout and A Predator Story

Monarch Fallout

It happened again in 2020. The convergence of the peak of the September monarch southerly migration over Southcentral Kansas was met by a strong south wind, causing a “fallout” of monarchs at the Dyck Arboretum. Rather than waste energy fighting the headwind, monarchs find a place of refuge to rest and sip nectar. I would estimate that I’ve seen this phenomenon happen five times in the Arb since 2005 and this year’s was the most memorable for a few different reasons including big numbers, fallout location, and a predator story.

Monarchs in the Hedge Row at Dyck Arboretum, 9/20/2020 – Photo by Gerry Epp

Big Numbers

The monarch numbers I observed on Monday, 9/21/2020 seemed to me to be more stunning than I can ever remember. I estimated conservatively in a report to Journey North, there were at least 500 monarchs resting in the Arboretum that day. But after giving it more consideration and talking to a local monarch tagger, Karen Fulk, I wonder if that number was more accurately in the thousands.

Karen’s many years of efforts to tag monarchs in Hesston has her keenly in touch with monarch phenology and migration patterns. She reports that the peak of migration through south central Kansas is usually between 9/22 and 9/27. This year, however, she started seeing an uptick in numbers when a cold front and north wind jump-started the southerly monarch migration a bit earlier.

Karen usually tags 300 annually during the fall migration. This year, Chip Taylor at Monarch Watch, knowing that migration numbers were higher this year, suggested that taggers order extra tags. Karen increased her number to 500 tags and was able to apply most of those when the fallout began Friday 9/18/2020 through Sunday 9/20/2020. Arboretum member, Gerry Epp, further documented this event by posting photos of the fallout on his Facebook page, 9/20/2020.

Monarchs on Seven Son Flower at Dyck Arboretum, 9/20/2020 – Photo by Gerry Epp

Fallout Location

With some repetition now in seeing these fallouts occur in the same place, I want to give some thought to why they congregate where they do at Dyck Arboretum. Karen usually tags at three places in Hesston based on the ability to catch and tag the maximum number in one place, and Dyck Arboretum is where she does the majority of her work. She estimated that 95% of her tagging this year happened at the Arboretum, based on seeing the greatest number of butterflies here.

I would hypothesize that they repeatedly congregate in the small 1/8th-acre area at the Arboretum amphitheater/pinetum for three reasons. One, they are seeking protection from the elements of wind and heat. This is about energy conservation. By escaping the wind and congregating in large groups on the north side of the dense hedge row of Osage orange trees, they are finding a microclimate that is cooler, more humid, and less turbulent than they would find on the south side.

Monarchs on Seven Son Flower at Dyck Arboretum, 9/20/2020 – Photo by Gerry Epp

Two, this location is next to a number of nectar sources. Why not rest where you can eat/drink too? Nearby native plant beds and a reconstructed prairie had a timely profusion of flowering from many species of the genera Helianthus (sunflower), Solidago (goldenrod), Symphotrichium (aster), Liatris (gayfeather), Eryngium (eryngo), and Heptacodium (seven son flower).

Three, a number of white pines in this location may resemble the trees of the Oyamel fir forests in Mexico. I don’t have any proof of this theory, but it seems plausible to me.

Predator Story

The newest wrinkle of this monarch fallout experience was the side story of five immature Mississippi kites. They were probably migrating with the monarchs and decided also to not fight the strong south wind. For a day and a half that I observed, this hungry bunch of pentomic predators took advantage of an abundant food supply. They hung out in the top of one of the white pines and took turns swooping through the monarch clouds to easily catch a snack.

Mississippi Kite Eating A Monarch at Dyck Arboretum, 9/22/2020 – Photo by Janelle Flory Schrock

Sometimes they missed catching their target, but usually, these agile insect catchers snagged their prey. Typically they would return to their perch to eat their catch, but sometimes they would eat in flight or “on the wing” as I hear experienced birders say. At one point, I counted approximately 120 monarch wings that had fluttered down to form what I’ll call a monarch confetti debris field. At four wings per monarch, that represented the carnage of about 30 monarchs. However, a number of wings had already been collected by onlookers, so it is not unreasonable to think that the number of monarchs preyed upon were double or triple what I saw.

Monarch Wings at Dyck Arboretum, 9/20/2020 – Photo by Brad Guhr

Monarch Toxicity

This predator behavior was a surprising observation. Monarch larvae eat milkweed and sequester in the mature butterfly wings and exoskeleton the milkweed toxins called cardiac glycosides. These heart poisons can seriously affect vertebrate predators, including birds, and often cause them to vomit and subsequently avoid eating them further. However, these young kites not only ate monarchs all day Monday, but they continued their feeding frenzy the next morning. Either their stomachs weren’t too adversely soured, or the calories needed to continue this migratory journey were simply too important.

A Google literature review turned up no articles mentioning this habit of Mississippi kites eating monarchs. However, a follow-up conversation with University of Kansas biology instructor, Brad Williamson, helped me understand that this observation is not so irrational. He explained that the monarch population is not 100% toxic.

“The individual toxicity depends a lot on the particular milkweed species that hosted the larval stage. Asclepias syriaca (common milkweed) and Cynanchum laeve (honeyvine milkweed) are not nearly as toxic as A. verticillata (whorled milkweed). There is an entire range of toxicity and it makes for some great mathematical modeling questions–just how much toxicity (percent toxic) in the population is necessary for protection for the entire population? How much metabolic costs are there for monarchs trying to process highly toxic host plants? Turns out that only 25-40% of the population being toxic confers protection for the remaining population.” (I will include below a bibliography on monarch toxicity that Brad Williamson provided if any of you are interested as I am in learning more about this topic.)

There were a lot of interesting biological and ecological issues at play here with these monarchs and kites. It was just one more interesting natural history story with subplots to be observed by those of us living in the Monarch Flyway. Until I’m able to one day witness the hundreds of millions of monarchs wintering in the the Oyamel forests of central Mexico, I am completely content having a front row seat to this fascinating migration phenomenon right here in Kansas.

Monarch butterflies observed at the Monarch Butterfly Biosphere Reserve in Michoacán, Mexico. Video by Beatrix Amstutz, February 7, 2020.

Plant Milkweed

To assist the monarchs and their annual migration, plant milkweed host plants and other native nectar plants for adults. Check out our annual spring and fall Flora Kansas native plant sales.

Articles on Monarch Toxicity

  • Brower, L. P., and C. M. Moffitt. “Palatability Dynamics of Cardenolides in the Monarch Butterfly.” Nature 249, no. 5454 (1974): 280–283.
  • Brower, Lincoln P. “Avian Predation on the Monarch Butterfly and Its Implications for Mimicry Theory.” The American Naturalist 131 (1988): S4–S6.
  • Brower, Lincoln P., and Susan C. Glazier. “Localization of Heart Poisons in the Monarch Butterfly.” Science 188, no. 4183 (1975): 19–25.
  • Brower, Lincoln P., Peter B. McEvoy, Kenneth L. Williamson, and Maureen A. Flannery. “Variation in Cardiac Glycoside Content of Monarch Butterflies from Natural Populations in Eastern North America.” Science 177, no. 4047 (1972): 426–429.
  • Fink, Linda S., and Lincoln P. Brower. “Birds Can Overcome the Cardenolide Defence of Monarch Butterflies in Mexico.” Nature 291, no. 5810 (1981): 67–70.Malcolm, S. B., and L. P. Brower. “Evolutionary and Ecological Implications of Cardenolide Sequestration in the Monarch Butterfly.” Experientia 45, no. 3 (1989): 284–295.
  • Malcolm, Stephen B. “Milkweeds, Monarch Butterflies and the Ecological Significance of Cardenolides.” Chemoecology 5, no. 3–4 (1994): 101–117.
  • Malcolm, Stephen B., Barbara J. Cockrell, and Lincoln P. Brower. “Cardenolide Fingerprint of Monarch Butterflies Reared on Common Milkweed, Asclepias Syriaca L.” Journal of Chemical Ecology 15, no. 3 (1989): 819–853.
  • Nelson, C. J., J. N. Seiber, and L. P. Brower. “Seasonal and Intraplant Variation of Cardenolide Content in the California Milkweed, Asclepias Eriocarpa, and Implications for Plant Defense.” Journal of Chemical Ecology 7, no. 6 (1981): 981–1010.
  • Roeske, C. N., J. N. Seiber, L. P. Brower, and C. M. Moffitt. “Milkweed Cardenolides and Their Comparative Processing by Monarch Butterflies (Danaus Plexippus L.).” In Biochemical Interaction between Plants and Insects, 93–167. Springer, 1976.
  • Zalucki, Myron P., Lincoln P. Brower, and Alfonso Alonso-M. “Detrimental Effects of Latex and Cardiac Glycosides on Survival and Growth of First-Instar Monarch Butterfly Larvae Danaus Plexippus Feeding on the Sandhill Milkweed Asclepias Humistrata.” Ecological Entomology 26, no. 2 (2001): 212–224.

How to Add Native Plants to an Established Prairie

As we wind down the growing season, now is a great time to take stock of your new prairie garden or established prairie landscape.  Which plants have done well?  What has struggled?  What needs to be moved?  Which plants need to be added?  These questions will help guide your efforts this fall and especially next season. 

If you have an established prairie, it can be challenging to make some desired changes.  To add a few plants to a mature landscape takes some forethought and planning.  The deep rooted natives have a distinct advantage over the immature perennial you are trying to get started.  Here are a few simple steps to help give these new plants a fighting chance.

Choose spots

Maybe you want to add some wildflowers into a prairie setting dominated by native grasses.  Visualize where you want these new plants.  Remember, a prairie has subtle splashes of color.  Sprinkling in a handful of wildflowers will look more natural. 

This couple is slowly adding a few native wildflower into their meadow. Some have even started coming in on their own.

Prepare the soil

With your spots chosen, now it is time to make room for these additions to your prairie.  We flag the spots and then spray them with Roundup.  These spots are usually not more than one foot in diameter.  If you want to avoid spraying, cut the area down to the ground and cover it with heavy cardboard for several months or over winter.  Secure these one foot areas with several inches of mulch or stones. 

Two or three inches of mulch will hold down the cardboard and smother out the existing plants.

Choose the right plant

I keep circling back to this point because it is so important.  If plants have struggled in an area, it is usually because either the soil or the plant is out of balance. Typically, the soil is not to blame. It is more likely that the soil and plant have not been correctly matched. Observe soil, sun and drainage issues and match the proper plant to your area. It is good to have a sense of how some of these natives grow naturally in community.  The more you know, the more successful you will be.   

Establish your plants

After waiting several months or over winter, it is now time to plant.  Establish plants using this method in either spring (April/May) or late summer (August/September).  If you sprayed the small areas, you can simply plant right into the open weed free soil.  If you put down cardboard and covered it with mulch, you can pull back a little of the mulch and slice through the cardboard. Put the plants into the ground and water daily.  Leave the cardboard and mulch to decompose over the next few years, as this will give the new plants a little room to grow with less competition.  The cardboard and mulch will ultimately disappear.

Next Steps

Over the next few years, it will be necessary to monitor these new plants.  It generally takes two to three years for the root systems to get fully established.  Remember to:

  • Water deeply as needed.
  • Make sure they are not getting too crowded by other vegetation. 
  • You may need to cut back nearby grasses so these new plants get enough sunlight.  This will only be necessary during this establishment phase. 
Native grasses are wonderful but a few wildflowers in the prairie make it even more beautiful and dynamic.

This process is not guaranteed to succeed, but we have used it successfully to add some diversity to an established prairie.  This approach can also be used to transform a smaller intensively planted display bed. Either way, plan now so you are ready to plant next season. 

Landowner Prairie Restoration Spotlight – Carolyn and Terry Schwab

Terry and Carolyn Schwab live on 109 acres in Eastern Harvey County affectionately known by a former neighbor as the “Foothills to the Flint Hills.” While much of the county land has been converted to cropland over the last century, the Schwab property has remained in remnant prairie.

We received a grant in 2004 to identify and study more than 100 prairie remnants in South Central Kansas and to collect seed for our 18-acre Prairie Window Project prairie reconstruction project on-site at Dyck Arboretum. Until 2010, this work helped us develop a prairie landowner network through which we consulted with landowners and assisted them with their prairie management needs. It was during these years that I had the pleasure of first meeting the Schwabs. Ever since I have enjoyed observing the dedication they bring to being prairie restorationists and natural area enthusiasts.

Terry and Carolyn Schwab and the property they manage (2007)

Increasing Wildlife Diversity

The property was a moderately overgrazed cattle pasture when they acquired it in 1993. The Schwabs’ main goal as land stewards was to increase wildlife diversity through improved habitat and enhance their avid hobbies of bird-watching and fishing.

The remnant prairie and emergent wetland above and around the ponds on their land can consist of hundreds of species of grasses, wildflowers, sedges, and shrubs. High plant diversity translates to high wildlife diversity. Maintaining diverse herbaceous vegetation also serves as a good surface water filter that improves pond health. Terry and Carolyn knew that without grazing or other forms of grassland management, invasion of a handful of tree species (including nonnative species) would create a dense, and comparatively lifeless, forest canopy within decades. Plant species diversity would decrease and wildlife habitat would suffer. They needed to become prairie restoration land stewards.

Dotted gayfeather (Liatris punctata) (Photo by Carolyn Schwab)

Vegetation Management

Controlling woody species and removing nonnative wildflowers became top priorities for the Schwabs in their quest to improve wildlife habitat on their property. Their initial efforts were extensive and laborious. They cut Osage orange and eastern red cedar trees and manually dug out musk thistle. To maintain water levels in the ponds, they repaired holes in the dams and removed trees whose roots can compromise dam life.

Numerous small trees invading in prescribed burning units A and B (2002 aerial photography)
Comparison with the previous photo shows that mechanical removal and prescribed burning have reduced tree cover over a six-year period, especially in units A and B (2008 aerial photography)

They were able to open up the upland areas where they had successfully removed mature trees and restore contiguous areas of grass and wildflower-dominated prairie. In these areas, the Schwabs implemented a regular rotation of mowing and prescribed burning to control any further invasion of woody plants. They networked with a local fire department to help them do this. They found mowing and burning to be much less labor-intensive than manual tree removal and effective tools for long term tree management.

Management Unit B, post-burn in 2009 (Photo by Carolyn Schwab)

Carolyn and Terry have made great improvements in restoring the prairie and emergent wetlands with tree management, but they know that they cannot rest on their laurels. Mature, seed-producing trees on their land and neighboring properties make keeping up with tree invasion a continual challenge. In addition to maintaining a routine of mowing and burning, they continue to cut and treat a number of invading tree species including honey locust, Bradford pear, Osage orange, Siberian elm, eastern red cedar, and the shrub Japanese honeysuckle. They are also on the lookout for the highly invasive, noxious weed sericea lespedeza which is becoming increasingly present in the area.

Conducting a prescribed burn on Unit C in 2010

Wildlife Monitoring

Carolyn invests a great deal of time monitoring and reporting on the biodiversity observed on their property. Daily walks to document bird populations, track phenology of flowering plants, and photograph butterflies are all part of what she sees as being an informed land steward.

Regal fritillary butterflies are dependent on habitat including diverse, large tracts of prairie. Even though the Schwabs have been improving the habitat of their prairie, regal fritillary numbers seem to be declining in recent years on a landscape scale. Carolyn has been planting nectar plants like butterfly milkweed and regal fritillary host plants (prairie violets) in the landscaping around her house to try and further support regal fritillary numbers.

This 2013 regal fritillary on butterfly milkweed (a yellow native landscaping variety near house) was the last one that Carolyn has seen on her property (Photo by Carolyn Schwab)

Carolyn is a top-notch birder. According to the Kansas Bird Listserv Database, a total of 329 species of birds have ever been documented as observed in Harvey County. Carolyn has seen more of these species (270) than anybody. And with easy access to 109 acres of prairie, wetland, woodland, and open water habitat, Carolyn has seen a whopping 232 of these species on her property!

A favorite experience of hers was witnessing a rare event on October 27, 2010. Eastern Harvey County is well east of the main sandhill crane migration flyway and seeing cranes there is not common. That night, however, the Schwabs observed 200+ sandhill cranes settle in for the night at their pond and enjoyed hearing their calls through the night. The cranes took off the next morning, but left behind a lasting memory for Carolyn.

Return of Butterfly Milkweed

The Schwab prairie restoration efforts are not only increasing the presence of grassland bird populations, but plant diversity as well. For years, they have not seen any butterfly milkweed on their property. But during the growing season of 2020, Carolyn reports that she has seen 20 plants.

Butterfly milkweed (Photo by Carolyn Schwab)

Protection for the Future

The Schwabs are considering registering their property with the Kansas Land Trust to protect this native prairie in perpetuity. By establishing a conservation easement on the property, Terry and Carolyn would be establishing guidelines for future landowners to follow that would help protect the prairie, watershed, and the diversity of species therein.

Thank you, Carolyn and Terry for your important prairie restoration land stewardship and for being willing to share your story.

A white-tailed deer doe and two fawns sheltering on one of the Schwab pond islands (Photo by Carolyn Schwab)

Our Maturing Reconstructed Prairie

Six years ago I wrote my first ever Dyck Arboretum blog post about our “Teenage Prairie” Prairie Window Project (PWP) reconstructed prairie. The birth and development of this project was the focus of my early years here at the Arboretum from 2004 to 2010 and at times it indeed felt like developing progeny. Sticking with that maturing prairie/human metaphor, I’d say this prairie today would be in the young adult stage. While it is still maturing, it relies much less on the parental influence of Arboretum staff and its changes from year to year are more subtle.

Prairie Window Project in September 2017
Prairie Window Project in August and October of 2010

I recently gave a 40-minute webinar presentation about the story of developing this PWP prairie. I enjoyed remembering all the educational and community building opportunities this project intensively afforded over a 7-year period and how it still serves us today. From that presentation, I will summarize through images and interpretation the stages this reconstructed prairie has been through.

Conceptual Stage

This reconstructed prairie was a gleam in the eye of Harold and Evie when they started the Dyck Arboretum in 1981. With native gardens already established here, they also wanted visitors to experience the feeling of visiting a larger prairie ecosystem. I was tasked with oversight of this project when I started working here in 2004. Preparations began in 2005 to turn 18 acres of agricultural ground south of our hedge row to a prairie.

The conceptual plan showing our existing grounds (in green) and the proposed PWP to be developed.
The red 1.3-acre rectangle was planted in 2005 and 2007 and the blue 5-acre oval was planted in 2009 and 2010 after earth moving added some topographical relief

Collecting Seed

We wanted this prairie reconstruction to be developed with local ecotype seed collected with in a 60-mile radius, knowing that the plants would be best suited to local fauna, soils, and climate. No other prairie in Kansas had been restored with local seed, and we knew this site could be a unique future seed source for creation of other prairies. We set out to visit more than 100 nearby blueprint prairies to collect data on their plant composition, study the butterfly and bird populations they supported, and scope out where we would best be able to hand-collect seed. Visits to these prairies on a regular basis helped us secure the grass, wildflower, shrub and sedge seed needed to plant a diverse prairie at Dyck Arboretum.

A graduate student collecting seed from a nearby remnant prairie
Volunteers collecting seed from a nearby remnant prairie
Harvesting large volumes of grass seed from nearby Harder Prairie with the aid of a KSU Ag Extension plot combine (Photo by Bob Harder)
Seed collection outings sometimes involved the collection of insects, rocks, sticks and more

Seed Mix

To best mimic the species composition of the blueprint remnant prairies we were observing, prairie restoration literature suggested that we should be aiming for a wildflower:grass ratio of no less than 50:50 and perhaps even has high as 80:20. Other target planting parameters included at least 50 lbs of seed per acre, a minimum of 50 seeds per square foot, and as much species diversity as possible. Five different plantings between 2005 and 2010 met these parameters and more than 120 local ecotype prairie species were planted into the PWP during that time.

Volunteers cleaning seed, removing chaff, and helping us best estimate seed weight that would insure the most accurate species mix calculations as possible
An example of the level of detail that went into planning the seed mix
2005 seed mix ready for planting

Planting Seed

Planting our seed mix with a seed drill or mechanical planter wasn’t realistic given the unique shape of our planting areas and diverse shapes/weight/textures of the seed mix. An alternative plan was to establish a planting grid that would allow for even distribution of seed using 5-gallon buckets. We assigned two buckets and a volunteer per planting unit, distributed seed (sand added for bulk) evenly to all buckets, and instructed volunteers to evenly cover their flag-marked planting unit.

Establishment of planting plots to best insure an even distribution of our seed mix
Volunteers walking to their assigned planting plots in January 2005
A graduate student distributing seed in January 2007

Prairie Management

Prairies require regular disturbance management of grazing and fire to maintain healthy ecosystems and prevent the invasion of woody plants and non-native cool-season grasses. Selective pulling of certain invasive, non-native species was key early in the PWP planting’s development. Once the desired prairie vegetation built sufficient roots after about three years and became well-established, a rotation of mowing (to best simulate grazing), burning and leaving residual has been implemented ever since.

Earth Partnership for Schools teachers pulling invasive non-native yellow sweet clover in June 2010
Volunteers helping conduct a prescribed burn in April 2018

Research

More than a dozen undergraduate and graduate students have been invaluable in collecting data to monitor populations of plant and wildlife species. Their efforts have helped us understand changes in groupings and species as the planting matures and management continues.

Graduate students conducting vegetation sampling July 2008
Vegetation guild importance value changes over 12 years (ANN=Annual, FAL=Fall Forb, ESP=Spring Ephemeral, LEG=Legume, C3G=C3 Grasses, C4G=C4 Grasses) (from study by Nat Dick, 2018)
Small mammal trapping and population monitoring on the PWP (Photo by Leonore Enfield)

Education into the Future

Our PWP reconstructed prairie is regularly used by preschool, K-12, and college students to learn about the plants and wildlife important to the natural history of Kansas. Community bird and butterfly enthusiasts regularly monitor the species that are found within. And visitors seeking recreation on our paths enjoy the prairie backdrop that enhances their Arboretum stroll.

Elementary school students collecting seed for a plant-growing project
Students conducting sweep netting to temporary collect and learn about insect populations
High school students collecting specific leaves as part of a scavenger hunt test during the finals of the Kansas EcoMeet

The Prairie Window Project prairie reconstruction on the southern part of our grounds has been a valuable tool to promote prairie conservation, education, and community building with our membership. This project has been at the heart of our mission to cultivate transformative relationships between people and the land. Pay this prairie a visit sometime and let us know if and how it may hold value for you.

October Richness

Life flies by for all of us and it is easy to miss or forget what happens in a given month. When reviewing recent photographs on my phone, I was pleasantly reminded of all the richness that happened over the last four weeks or so. October in Kansas is that great fall transition period between summer and winter, hot and cold, green and brown, and fast and slow when there is SO MUCH to see. For those that feel that they endure the extremes of Kansas to revel in the moderation that comes with fall, October is your time.

I was reminded from these photos of our Dyck Arboretum of the Plains mission – cultivating transformative relationships between people and the land. Let’s review in the following photos the richness that can be found in that interface between the plants/wildlife of Kansas and the people that enjoy this place in October.

Monarch fallout.

October 1 brought a monarch “fallout” when their migration was interrupted by strong south winds. They momentarily took a break from their journey and sought shelter in our Osage orange hedge row.

Tagged monarchs.

Local monarch enthusiast, Karen Fulk, took advantage of the fallout to capture and tag monarchs with identification numbers that help other monarch observers in Mexico or elsewhere to better understand the speed and location of their migration.

Middle school students measuring tree height with the “rough estimate” method.

Santa Fe Middle School students from Newton were able to witness the end of the monarch fallout on October 2 and also enjoyed various activities on the Dyck Arboretum campus that included insect collecting, plant sampling and measuring tree height. The Dyck Arboretum’s Kansas Earth Partnership for Schools (EPS) Program curriculum has a lesson that teaches students how to measure tree height with five different methods including estimation, shadows, algebra, geometry, and trigonometry.

Measuring tree height.
Lorna Harder teaching a 5th Grader about plant identification.

On October 6, former and current Dyck Arboretum board members hosted tours of their homes and land near Hesston for Arboretum Prairie Partners. Lorna and Bob Harder gave a tour of their solar photovoltaic-powered home and surrounding prairie landscape and LeAnn and Stan Clark hosted everyone for dinner on their patio surrounded by extensive native plant landscaping.

Lorna Harder leading a tour of the native prairie she is helping steward.
Director, Scott Vogt, welcoming Arboretum Prairie Partners to a meal on LeAnn and Stan Clark’s patio.

Hesston Elementary students took a field trip to the Arboretum on October 10 to conduct a leaf scavenger hunt, learn about monarch migration, observe different seed dispersal mechanisms and study insect diversity in the prairie.

Hesston Elementary students search for insects in the Arboretum reconstructed prairie.
Finding seeds, grasshoppers, beetles, flies, spiders, true bugs, and more.
Insect sweeping.
Students found a female striped wolf spider carrying its newborn young on its abdomen.
Grasshoppers are plentiful in the prairie during October.
Initial insect skittishness turned to fondness during the field trip.
Beehives at Earhart.

Earhart Environmental Magnet Elementary in Wichita, a Kansas Earth Partnership for Schools participating school, engages their students in environmental education with hands-on activities such as beekeeping. Students tend the bees, grow and maintain native plant gardens as nectar sources, and regularly camp on their grounds to learn more about the natural world around them.

Earhart students check a birdfeeder while searching for insects in one of their courtyard native plant gardens.
Earhart students found a ” burnt marshmallow” Chinese mantid egg casing or ootheca.

On October 17, Walton Elementary (another Kansas EPS School) students came to the Arboretum to collect seed and study how seeds disperse. They each had a target plant they were searching for and from which they were aiming to collect seed. They did the same last year, germinated the seed in their greenhouse over the winter, and had a successful native plant sale in the Walton community.

College students observing a garter snake.

Bethel College environmental science classes visited the Arboretum on October 24 to learn about the native plants and wildlife of Kansas, natural resource management, and ecological restoration. When students become interested in and well-versed about the natural world around them, they will turn into more informed and better-educated environmental decision-makers of the future.

Bethel students found a Pandorus sphinx moth caterpillar crossing an Arboretum sidewalk.
‘Tiger Eyes’ sumac from an Arboretum plant sale was in autumn splendor on October 26 at my house.

Part of establishing a rich sense of place for people in any one location involves not only natural history connection cultural enrichment through the arts. The Dyck Arboretum’s Prairie Window Concert Series (PWCS) features eight live music performances each season. Our 2019-20 season was kicked off with October bookend performances featuring Mark Erelli on September 29 and recently The Steel Wheels on October 26.

Mark Erelli – the first show of the 2019-20 PWCS.
The Steel Wheels – the second show of the 2019-20 PWCS.

On October 29, a stunning cold front rolled through Kansas and chilling temperatures caused delicately-held leaves on trees like ash, maple, Osage orange, and ginko to fall within hours. Social media posts were featuring leaves dropping quickly that day all over Kansas to make for a memorable fall day.

Ginko leaves and ‘iron butterfly’ ironweed.

The 2019 Eco-Meet Championships will be held at Dyck Arboretum in early November. In late October, organizers and high school teams from around the state were visiting the Arboretum to prepare for the big event. The competition will allow some of the brightest science students from around the state to showcase their knowledge on subjects including prairies, woodlands, entomology, and ornithology.

Students from Smoky Valley High visited the Arboretum on October 31 to prepare for Eco-Meet.

The cold nights and relatively warm days of late October have allowed the grass and tree leaves to show off their bright colors that have been hidden all growing season by the green pigments of chlorophyll. Seed heads are opening and dispersal mechanisms that catch the wind or lure animals are on full display. Good ground moisture and warm temperatures are still even allowing for a bit of late-season flowering from some species.

Sugar maple.
Little bluestem.
Seeds dispersing from a common milkweed pod.
The fall prairie is loaded with seeds this season which is good for seed-eating mammals and birds.
It has been a mast year for trees and the ground under this burr oak was covered with acorns.
Late season flowering by Leavenworth eryngo.
Aromatic aster ‘Raydon’s Favorite’.

I’ll leave you with a video (sorry for the terrible camera work) of one of my favorite sights of every October – when the aromatic asters are in full bloom and late-season pollinators belly up to the nectar bar on a warm fall day. Enjoy.

Video of Pollinators nectaring on aromatic aster ‘Raydon’s Favorite’