Right now in prairies, woodlands, roadside ditches and home gardens, wonderful displays of native grasses along with wildflowers blooming yellow, white, and lavender are putting on quite a show. The yellow wildflowers are most likely either sunflowers or goldenrods. Each is quite beautiful and teeming with pollinators.
Goldenrods are just as diverse and variable as sunflowers. While many landscape plants have already reached their peak and the flowers have faded by September, goldenrods have become the stars of the show as they brighten up the landscape. Their golden yellow autumn inflorescences are striking.
In spite of their attractiveness, goldenrods have a reputation for causing allergies. In truth, this is unlikely, because goldenrod pollen is large and heavy and is not carried by the wind. Rather, it is giant ragweed (Ambrosia sp.) that is spreading pollen through the air at the same time.
These wildflowers are insect-pollinated by many wasps, moths, beetles, honey bees, monarch butterflies and other beneficial pollinators searching for a sip of nectar. In total, 11 specialist bees and 115 different caterpillars need these plants. There are around 50 species of insects with immature forms that feed on the stems of goldenrod. In addition, seeds and foliage provide food for some birds and mammals. Across the board, goldenrods are of huge value to wildlife and one of the keystone wildflowers for pollinators.
Goldenrods are adaptable to a wide range of conditions in nature, making them a great choice as a landscape plant. They grow naturally in soils from wet to dry. Even the drought conditions we have been experiencing have not kept these denizens of the prairie from blooming. There is a goldenrod that will grow in your garden.
For all their positive attributes, there are goldenrod species that don’t belong in a formal garden. Canada goldenrod for example is a highly aggressive species that spreads by underground rhizomes and seed, ultimately pushing out other smaller desirable plants. It will take over a garden in a couple of years. However, in a prairie setting with the deep roots of native grasses and competition from other plants, it can be mostly kept in check. That is why we recommend clump-forming goldenrods as a more reliable choice for the landscape relegating those aggressive species to the prairie or outskirts of the landscape (along a fence or in an alley) where they are free to roam and spread.
I like Solidago rigida, Solidago nemoralis, Solidago ‘Wichita Mountains’, Solidago canadensis ‘Golden Baby’, and Solidago ‘Fireworks’ for sunny areas. For shade, I choose to plant Solidago odora, Solidago ulmifolius or Solidago caesia. It is safe to say that goldenrods are powerhouse plants that deserve a place in your native garden.
Two years ago, I reported on an unusual convergence of migratory paths during the 2020 monarch fallout event here at the Arboretum. As we anticipate an abrupt change in weather and the official arrival of fall with tomorrow’s autumnal equinox, I encourage everyone to keep an eye out for similar monarch migration events in your natural areas.
(Original publication date: October 7, 2020)
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.
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.
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.
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.
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.
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.
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.
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.
One of the questions we get at every fall plant sale is “can we plant these grasses now?” The answer is “yes, we encourage fall planting of native grasses”, but with some caveats.
Here are a few questions to answer before you jump into planting native grasses this fall such as:
Is your area ready to plant now?
Are you able to water it daily for the first few weeks and into the winter if needed?
Do you have the right location for these grasses?
I tend to err on the side of caution for late fall planting because losses can be incurred. However, you can be successful if you follow a few guidelines.
Around South Central Kansas, our first average frost is October 15. Typically, we plant native grasses as soon as possible in late August or early September to give them more time in the ground to get established. As a general rule, it is best to have native grasses in the ground three to four weeks prior to the first fall frost. This will give the plant time to get established with roots fully attached to the soil to absorb water and nutrients through winter.
This attachment by the roots to the soil is so important because it keeps the grass from being heaved out of the ground. The natural freezing and thawing of the soil during the winter can be extremely strong, pushing partially established plants out of the ground and breaking roots, which results in desiccation and death of the plant. Properly establishing plants before winter will protect them from this force.
Another factor to successfully transplanting grasses in the fall is soil temperature. Typically, native grasses will continue to grow (root) with soil temperature above 60 degrees. So installing grass plugs in August through mid-September is a proven strategy, because soil temperatures remain optimum until after the first frost.
We have had success with planting native grass in the fall. The most obvious benefit of this approach is that the grasses will break dormancy next spring fully established and ready to grow. As temperatures warm they will have a head start over early spring plantings.
Note: It is always good practice to check the soil around fall planted perennials (including grasses), trees and shrubs during the winter for moisture. If the top one to two inches of soil is dry, it is good to give them a light watering. Remember, they are dormant so they don’t need much.
Warm Season Grasses for fall planting:
Big Bluestem Andropogon gerardii and cultivars
Sideoats Grama Bouteloua curtipendula
Blue Grama Bouteloua gracilis
River oats Chasmanthium latifolium
Pink Muhly Grass Muhlenbergia reverchonii
Mexican Feather Grass Nassella tenuissima
Switchgrass Panicum virgatum and cultivars
Little Bluestem Schizachyrium scoparium and cultivars
While walking on the island recently, I saw a change in the vegetation this year. During the renovation we brought in new soil, drove around, made new ruts, and stirred up the seed bank below. This disturbance altered the landscape enormously, and it will take years to transform back to what it was, if ever.
The first thing I noticed is how many more annual plant species there are on the island. Some are weeds – like velvet leaf, Abutilon therophrasti – and some are native species, though they may be unwelcome spreaders, like annual sunflower. These either arrived with the new soil, or were churned up to the surface while driving with heavy equipment. When annuals appear suddenly in a bare patch of an otherwise mature and established prairie, with a little help they will disappear just as quickly. We cut the seed heads off to stop them from returning next year, and soon they will be outcompeted by the perennials and grasses.
But I do hope some annuals stick around! Partridge pea, a favorite of mine and host to Sulphur butterflies, has appeared on the island once again, and I’d like to see more of it seed out. This plant loves tough, disturbed areas, so it is no surprise it showed up here.
New Animal Activity
We have noticed our aspen trees falling one by one, and see the sharp points of their chiseled trunks. We have a beaver on our island! While we have never caught sight of it, it is obviously enjoying our grounds immensely. With the aspens mostly gone from the center of the island, the views have changed. Visibility is better to the east and it is sunnier in the sitting area.
Beavers are shapers of entire ecosystems, and they are integral to rivers and streams. And while I love the idea of having a beaver around, our pond is in fact not a natural water way, and too many of our memorial trees are at risk from our industrious friend. But he sure has caused his share of disturbance around here! The shrubs growing beneath the aspens appreciate the increased sunlight, I am sure. We successfully lived-trapped one of the two beavers, and relocated it to a new pond with the permission of the property owner.
Who Are You?
There have even been a few perennials popping up that are new to me. These might have been in the soil for years, but sprouting only when given open soil and right conditions. One of these is narrow leaf golden aster. A lovely little plant making its debut right along the edge of the gravel path. There is also a large, very conspicuous patch of Rudbeckia subtomentosa that I didn’t know we had on the grounds. Just when I think I have seen every inch of our grounds, it is nice to be surprised by these new flower faces!
Please DO Disturb
Prairies, even tiny ones on the island or in our residential gardens, are meant to change. Nothing is static in nature, and when we humans want it all to stay orderly, predictable and exactly the same year after year, we are playing a losing game. It’s much better to embrace the changes in our gardens and landscapes, and even encourage them.
Some perennials will live fifty years, while others may only live five. Everything has its expected lifespan, so when those bare spots appear in your garden, consider throwing out some native annual seed like Coreopsis tinctoria or partridge pea. These will fill the gap, provide lovely blooms, then fade away once your other plants cover the soil. After all, prairie landscapes evolved to be disturbed, either by fire, flood, or the thundering of bison hooves. Each of these creates open soil for new plants to grow and compete with the existing grasses and forbs.
Are you looking to create a dynamic, ever-changing prairie habitat of your own? Visit FloraKansas Native Plant Days next week and ask staff what native plants will work best in your landscape.