Wetland Wildflowers

With the recent rainfall, I have been reminded that native plants are a wonderful and underused means to create a natural setting around a water feature or low area in your landscape. Most prairie wildflowers and grasses don’t do well in soggy soil and excessive moisture results in rot and other deadly diseases. However, there are a handful of plants that grow in wet areas within a prairie or along pond margins. These wetland wildflowers appreciate wet feet and some even thrive in standing water. Rather than radically altering the drainage of a soggy, poorly drained site within your garden, try some of these plants that grow well in such conditions. 

Swamp milkweed (Asclepias incarnata)

As the name implies, swamp milkweed prefers wet locations in full sun to partial shade. Here at the Arboretum we have it growing next to the pond and stream. In the wild, it is found in prairie seeps and potholes, at the edges of marshes, and in wet ditches. Swamp milkweed grows 3 to 4 feet tall and blooms from July, August and early September. The vanilla-scented flowers are typically pale pink to rose-purple and are a favorite for migrating monarchs. 

Swamp Milkweed in bloom

Joe Pye weed (Eutrochium maculatum)

This tall, native perennial is found in moist meadows and marshes. The attractive leaves and purple spotted stems fill out this 6 foot tall wildflower. The rosy-pink bloorms in mid to late summer are a favorite of many pollinators. Joe Pye weed performs best in moist to wet soils in full sun. Smaller forms like ‘Baby Joe’ and ‘Little Joe’ are nice alternatives if you don’t have much space. 

Eutrochium maculatum ‘Gateway’

Blazing Star- (Liatris sp.)

You don’t typically think of blazing star as a wetland wildflower, since most species prefer dry sites. However, there are several species of Liatris that can handle wetter conditions. Kansas gayfeather (Liatris pycnostachya) and dense blazing star (Liatris spicata) are typically found in moist prairies and meadows. These blazing stars grow 3 to 4 feet tall with narrow, lance-like leaves and blooms in mid- to late summer.  The pinkish purple flowers grow on 12- to 18-inch-long, upright spikes.  Flowering begins at the top of the spike and moves down the stem.   

Liatris pycnostachya and gray headed coneflower on the pond edge

Other wetland wildflowers

  • Acorus calamus – Sweet Flag
  • Actinomeris alternifolia – Wingstem
  • Aster novae-angliae – New England Aster
  • Eupatorium perfoliatum – Common Boneset
  • Filipendula species – Meadow Sweet
  • Galium odoratum – Sweet Woodruff
  • Helenium autumnale-Helen’s Flower
  • Helianthus angustifolius – Swamp Sunflower
  • Hibiscus species – Rose Mallow
  • Iris virginica – Southern Blue Flag
  • Lobelia cardinalis – Cardinal Flower
  • Lobelia siphilitica – Blue Cardinal Flower
  • Mertensia virginica – Virginia Bluebell
  • Monarda species – Bee Balm
  • Physostegia virginiana – Obedient Plant
  • Pycnanthemum tenuifolium – Narrow Leaved Mountain Mint
  • Ratibida pinnata – Gray headed Coneflower
  • Senna hebecarpa – Wild Senna
  • Thalictrum dasycarpum – Purple Meadow Rue
  • Tradescantia sp. – Spiderwort
  • Verbena hastata – Blue Vervain
  • Veronicastrum virginicum – Culvers Root
  • Vernonia noveboracensis – Ironweed

Native grasses are quite adaptable, but several grasses and sedges can grow well in moist to wet soils. Big bluestem (Andropogon gerardii), switch grass (Panicum virgatum), prairie cordgrass (Spartina pectinata) can be found in roadside ditches, prairie bogs, and along pond edges. There are many native sedges such as gray’s sedge (Carex grayi) that perform well in moist soils in partial to full sun as well. 

If there’s a drainage problem in your yard, you may be inclined to install a dry creek bed or a French drain. But don’t be too quick to go to all that work. An alternative route is to simply use plants that prefer to live in wet areas. Match plants that are native and naturalize in wet conditions. Wetland wildflowers have adaptations to grow in wet soil, so they are effective landscaping solutions for areas with drainage issues.

Wildflowers for Low Maintenance Areas

When you mention wildflowers, people tend to visualize broad swaths of colorful flowers growing in meadows. This effect is often very difficult to achieve because of problems with soil preparation, plant establishment, weed control, and long term maintenance. Finding a solution to these problems usually requires more time and effort than most people want to invest.

Black-eyed Susan (Rudbeckia hirta)

Many wildflowers can be naturalized in low maintenance and unmown areas where they can reseed themselves or spread via roots. Black-eyed susan (Rudbeckia hirta) is a good candidate for naturalizing. Common in Kansas, the bright yellow ray florets with the characteristic brown, domed centers are a familiar site in June and July. Black-eyed susan is a vigorous biennial to short lived perennial that self-seeds readily. It will thrive in low a maintenance area with little care. 

Black-eyed Susan

Clasping coneflower (Dracopis amplexicauslis)

This annual grows 18-24 inches tall and produces masses of large yellow flowers from late May well into July.  The flowers are similar in appearance to black-eyed susans, but the ray flowers tend to droop downward. Also, they often have a dark red-brown band near the base of each individual ray floret. Clasping coneflower, a copious seed producer, thrives in clay soils and will often form dense colonies in moist soils. In late May and June, it is very showy in low fields and ditches in the Flint Hills of southeast Kansas.

Showy evening primrose (Oenothera speciosa)

This somewhat sprawling to upright perennial is common along roadsides in central Kansas. While white is the most common color, pink flowered forms can be found in this area as well. It generally blooms heavily from mid-April into June and then produces sporadic blossoms throughout the summer and fall. It seeds readily but usually takes two years to produce blooms. Here at the Arboretum, we have both the pink and white forms that produce a solid mass of flowers for over six weeks in the spring.

Showy Evening Primrose Photo by Emily Weaver

Mexican hat (Ratibida columnifera ‘Red’) and yellow columnar coneflower (Ratibida columnifera)

Typically, these upright clump forming perennials have abundant red tinged or bright yellow daisies with drooping ray petals around a prominent central cone – resembling a sombrero. The flowers are pollinator magnets, providing weeks of color and insect food. These wildflowers perform best in full sun and medium to dry moisture.  The attractive seed heads add late season interest and birds seek out the seeds in the fall and winter. 

Columnar coneflower photo by Emily Weaver

Other wildflowers

  • Bee balm, Monarda fistulosa
  • Leavenworth eryngo, Eryngium leavenworthii
  • Willowleaf Sunflower, Helianthus salicifolius
  • Maximillian Sunflower, Helianthus maximilianii
  • Common milkweed, Asclepias syriaca
  • Showy goldenrod, Solidago speciosa
  • Canadian goldenrod, Solidago canadensis
  • Grayhead coneflower, Ratibida pinnata
  • New England Aster, Aster novae-angliae
  • Hoary vervain, Verbena stricta
  • Blue vervain, Verbena hastata

All of these species are true wildflowers. They are aggressive, thrive with neglect and will continue to reseed and spread for many years. We recommend planting them from seed in late fall or early winter. Other desirable wildflowers can be added to these natural areas but do not try to plant these in your perennial border among your garden variety perennials and annuals. They will soon take over. They are best left to brighten the wilder areas of your yard and garden. Enjoy them from a distance.

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.

Lessons from my small shade garden

I have two large pin oak trees in my back yard.  They are one of the reasons I purchased the house.  They are healthy – for the most part – and don’t suffer the blight of most pin oak trees in south central Kansas, Iron Chlorosis.  I appreciate the shade they give my house, especially in the late afternoon.  Each of them is about 50 years old. I have long been envisioning a shade garden underneath them.

Last spring, I finally got around to planting a few shade plants in a small space I had developed long ago under one of these trees.  I was determined to find some plants that would grow in the shadow of this tree.  Root competition is a problem as well.  Honestly, I have struggled to grow anything under their shade. 

Woodland Phlox

Here are a few of the plants that survived in my shade garden, with a few even already blooming this spring.

  • Woodland Phlox
  • Barren Strawberry
  • American Columbine
  • Yellow Columbine
  • Bluebird Columbine
  • Variegated Solomon’s Seal
  • Solomon’s Seal
  • Elm-leaf Goldenrod
  • White Woodland Aster
  • Mayapple
  • Liverleaf
  • Golden Ragwort
  • Herman’s Pride Yellow Archangel
  • Sweet Woodruff
  • Rose Sedge
  • Evergold Sedge
  • Plantain Sedge
  • Pennsylania Sedge
  • June Hosta
Rose Sedge
Plantain Sedge

Watering

As you can see, I had quite a few plants survive these adverse conditions.  One of the biggest lessons was to regularly water the area.  I spent the first three weeks after planting hand watering each plant.  Once I noticed that the plants were starting to put on new growth, I backed off the watering and just watered as needed.  I would frequently check the top inch or two of soil for moisture.  If it seemed dry, I would hand water again.  I followed this regimen throughout the remainder of the growing season.  Keep in mind that you are trying to grow shade plants in an area that was once predominately prairie.  Supplemental moisture is required for those plants to survive. 

Sweet Woodruff

Leaves

Essentially, I left the leaves as they fell from the tree to a depth of one to three inches.  These leaves are good insulation and eventually break down to release nutrients.  Of course, too many leaves can be a problem too.  Gently remove excess leaves that blow in from other areas.

Barren Strawberry

Disappearance

I had some plants disappear last summer.  Some of the Solomon ’s seal faded into the soil.  Remarkably they are coming back to life this spring.  I kept watering them even though they went dormant.  A spring ephemeral like mayapple is supposed to go dormant, so I was certain it would return. However, the solomon’s seal made me wonder about their survivability.  Shade plants are resilient.  They surprised me with their return this spring. 

Mayapple
Solomon’s Seal

A few additions

Bolstered by my success, here are a few plants I plan to add to this new shade garden.

  • Geranium maculatum ‘Crane Dance’
  • Celandine Poppy
  • Crested Iris
  • Jack in the pulpit
  • Bluestem Goldenrod
  • Early Meadow Rue

I have been reluctant to start converting my dark and barren patch of ground into a shade garden.  It has been really rewarding to see this garden come to life this spring.  It took a little forethought and tenacity to make this garden take shape.  It is not perfect, but I have a better handle on how to enhance it and help it through our Kansas summers.

Native Grasses for Color, Movement and Structure

Many people have a love/hate relationship with ornamental grasses.  They know they need them in the landscape, but the loose, naturalistic look of grasses makes the garden seem untidy or a little too “wild”.  However, these attitudes are beginning to change, especially as people notice how landscape designers like Piet Oudolf incorporate native grasses throughout their designs.  Unkempt gardens are suddenly becoming vogue.    

Native grasses can be wonderful assets, bringing color, structure and varying textures to the garden. In the autumn and winter, grasses harmonize and soften the landscape providing movement with the gentlest breeze. More and more, I have been blending grasses into designs.  Grasses anchor a landscape and they are tough and resilient, too. Drifts of grasses all through the design along with mixing and matching grasses with wildflowers for structure and contrast looks more prairie-esque. 

There are new varieties of ornamental grasses to choose from every year.  Native grasses with their deep roots are suited to dry and sunny conditions, some even can thrive in wetter soils.  The following list of grasses we use here at the Arboretum in sunny borders and intermingled with wildflowers. They will be available at the spring FloraKansas: Native Plant Festival.

Big Bluestem (Andropogon gerardii)

This is the king of the prairie grasses, reaching to the skies and sending its roots deep.  It perseveres in tallgrass prairies. The vertical stems stand firmly, sway with only a slight breeze, and change vibrantly in the fall to shades of red and orange.  The three-pronged seed heads resemble a turkey’s foot, hence its other name “Turkey Foot Grass”.  Plant it in full sun in a medium to moist soil. ‘Blackhawks’, ‘Red October’ or ‘Rain Dance’ are nice varieties to use in the landscape. 

Big Bluestem/Turkey foot grass

Switchgrass (Panicum virgatum)

The airy seed heads and upright habit make this a great landscape grass.  These forms make quite a statement in the fall and winter landscape.  They add structure, texture and movement. For best results, plant them in a sunny spot in a medium to moist soil. It is very drought tolerant. Discover these varieties: ‘Northwind’- consistent upright form to four feet tall and golden yellow fall color, ‘Cheyenne Sky’- red leaves develop early in the summer and grows to three feet, and ‘Dallas Blues’- tall (to 8 feet), with blue foliage and purple seed heads.

Northwind Switchgrass
Cheyenne Sky Switchgrass with Rigid Goldenrod

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Indian Grass (Sorghastrum nutans)

The yellow/tan plumes and vase-shaped habit make this grass easy to recognize in prairies. I use them in naturalistic plantings or formal plantings.  Give them space, because mature plants can be five feet across the top. It grows best in a medium to dry soil and all-day sun. Heavy clay soils make it robust, but it thrives in many different soil types.

Indiangrass Seedhead Plumes

Blue Grama (Bouteloua gracillis ‘Blonde Ambition’)      

This Blue Grama Grass is apparently on steroids. I cannot believe how vigorously it grew this year, ultimately reaching two feet tall. This taller form has bright blue-green leaves that are topped by a host of eyelash-like golden yellow flowers. They wave in the wind and ambitiously last from summer into the fall and winter months.  I used it along a walkway but it is so attractive that it could stand on its own providing many months of ornamental interest. This beautiful grass was discovered by David Salman of High Country Gardens.


Little Bluestem (Schizachyrium scoparium)

At home in a formal planting or prairie garden, you don’t have to sacrifice anything by planting Little Bluestem. for the most part it remains upright even through the winter. The gentlest breeze puts the plant in motion. The blue-green leaves are highlighted by pink that gradually turn to rich copper, pink, and mahogany tones in the fall. It truly has a carousel of color. It provides a beautiful backdrop to perennials like coneflowers or black-eyed Susans. This graceful, low maintenance Little Bluestem will provide a form that can be used in any sunny landscape. Other garden-worthy varieties of Little Bluestem are ‘Twilight Zone’, ‘Standing Ovation’, ‘Blaze’ and ‘Blue Heaven’.

Blue Heaven’ Little Bluestem


Prairie Dropseed (Sporobolus heterolepis)

At one time, this was the top selling native grass in the country. To see a mass planting in full bloom, you can understand why it is so popular.  The narrow leaves form a perfect fountain of green. In late summer, the fragrant airy seed heads develop.  Some liken the fragrance of the blooms to buttered popcorn. With this plant, you can get your theater popcorn fix without all the calories. It requires almost no maintenance once established. Fall color is burnt orange and rivals Little Bluestem in mass plantings. 

Prairie Dropseed with Giant Blackeyed Susan and Yellow Coneflowers

There’s really nothing like tall grasses waving in the breeze. The colors and textures change with the seasons. Don’t forget, they also provide a crucial habitat for birds and pollinators. They are in more and more of my designs because they add so much to the landscape. They don’t necessarily bloom in the same way that wildflowers do, but native ornamental grasses are both functional and visually appealing throughout the growing season and into the winter.


Landscaping to Attract Pollinators

This time of year, we are all evaluating our yards and landscapes as we prepare for spring.  If you are like me, you want your landscape to do so much more.  I want beautiful plants and season-long bloom.  I want to choose plants that require less water.  I want to provide a setting that attracts pollinators and wildlife of all forms.  For those focused on gardening to attract pollinators, here is a checklist to follow to welcome more wildlife into your landscape. 

Meet their basic needs

Generally, pollinators need three things: food (nectar and pollen), water and shelter.  Native plants are more attractive to different pollinators than exotic (non-native) plants.  These native pollinators have adapted to the life cycles of the native wildflowers and seek them out. 

Photo by Dave Osborne

Choose location wisely

Native plants generally require less water and thrive with minimal attention if properly sited and established.  Take the time to do your homework and choose plants that grow best in your soil and site conditions.  Look for a sunny area (6+ hours of direct sunlight) with areas of shelter on the peripheries from strong winds.  Design your landscape to include a water source.  A simple bird bath with a stone inside so pollinators can land will suffice. 

Design in clusters

A cluster of wildflowers of one species in bloom will attract more pollinators than individual plants scattered throughout the landscape.  I like to plant in odd number groups such as three, five, or seven and include plants with purple, yellow, white, blue or violet. 

Provide diverse nectar sources

Wildflowers come in a variety of shapes and sizes.  This diversity is attractive to pollinators, too.  There are over four thousand species of bees in North America.  They are different in size, shape and they feed on different shaped flowers.  Having a diversity of plants means more pollinators can benefit. 

Succession of bloom

Wildflowers should be coming into and out of bloom throughout the growing season.  With several plant species flowering at once, and a sequence of plants flowering through spring, summer and fall, you will sustain a range of pollinator species that fly at different times of the year. 

Plant milkweeds

Monarch Watch encourages the planting of milkweed species because monarch larvae feed exclusively on milkweeds.  Milkweeds are so important to the life cycle of monarchs.  For our area, they recommend common, swamp, butterfly, spider, and Sullivant milkweeds.  We will have these milkweeds at our spring FloraKansas Native Plant Festival.

Native Plant Guide
Monarch caterpillar on common milkweed

Identify your motivation

Is it important to provide habitat for bees and butterflies?  Is it important to conserve water?  Do you want more from your landscape than sporadic blooms and a haphazard design?  Are conservation and stewardship efforts important to you? 

Monarch populations have been dwindling.  Bees are threatened by the environment, disease, pesticides, herbicides, and beehive decline. According to Monarch Watch, the United States consume habitat for monarchs and other wildlife at a rate of 6,000 acres a day, or 2.2 million acres per year.  We could help offset these losses by creating a landscape that welcomes birds, pollinators and other wildlife. 

If you have questions about landscaping with native plants, the Arboretum staff or volunteers can help you plan and design a landscape that will attract pollinators AND meets your expectations.  Check with us during the spring FloraKansas Native Plant Festival.  We offer species and varieties that pollinators love.  No amount of effort is too small to have a positive impact.

Succession of Bloom

Every gardener strives to have a continuous symphony of flowers in their gardens from spring through fall.  However, most gardens, including some of mine, seem patchy in appearance with sporadic blooms from time to time.  Although a continuous floral bloom is the goal, it is often not achieved unless a method called succession planting has been implemented. 

Succession of bloom is used to describe a diverse set of plants in a flower border that will always have interest. At any given time during the growing season there are plants coming into bloom and fading out of bloom.  This consistent bloom is important in a design, especially when using native plants.   

Tallgrass Prairie National Preserve in the Flint Hills. Photo by Brad Guhr

There are no Wave Petunias in the prairie. If you visit a prairie landscape like the Konza Prairie every two to three weeks throughout the year, you will observe plants beginning to bloom, in full bloom or going out of bloom. That is how you need to design your native landscape. Include plants that bloom in every season of the year and then strategically add grasses for movement and texture in the winter months.

In my opinion, succession of bloom is one of the most important concepts in native plant design, right after site considerations and matching plants up to your site. Take time to acquaint yourself with the life cycles of wildflowers and grasses. The more you know, the easier it will be to seamlessly incorporate them into your design. Succession of bloom always provides something of interest in the garden, but it also provides season-long food for pollinators and other wildlife.   

Starting a List

Put together a list of plants that bloom at different seasons and will grow well in your area.  Include early season bloomers, midseason bloomers, and late season bloomers. Select a set of grasses that combine well with those wildflowers or provide backdrop for other perennials in front of them. 

Native Plant Guide
Working on a landscape design for one of our members.

Begin the Design

As you layout your plants in your design, think about heights and layer of plants. Typically, there are only three or four layers of plants.  Plants 4-18 inches tall in the front, middle layers of 18-24 inches and 24-48 and then taller perennials at 48+ inches tall.  These tiers guide how I combine the plants and layout the design. 

Initial planting next to the Prairie Pavilion.
Needs more grasses and wildflowers to fill the gaps and cover the mulch.

Layout

Always think about foliage and flowers. In matrix planting, made popular by Dutch landscape designer Piet Oudolf, every square inches is covered with plant material.  From the groundcover layer through the seasonal interest layer and on up through the structural layer, plants crowd out weeds and mimic the prairie community.  Keep in mind, blooms will fade, so foliage is important too. Seed heads can be supported and highlighted with grasses. A striking example is the dark seed heads of coneflowers later in the season with little bluestem.

Little Bluestem and Pale Coneflower seedheads

Plant in smaller groups

I prefer to plant is smaller groups such as five, seven or nine individual plants. Often, I will mix in some native grasses with the wildflowers. A larger swath of something out of bloom leaves a large void in the design, especially if it blooms in the spring. Plant closely enough so that foliage intermingles. If plants are spaced too far apart that there is more mulch or soil than plants, this void will draw your eye to the plant that is out of condition. By planting densely, you will hardly notice a plant out of bloom. 

The example below is simplistic, but the concept is the same. Succession planting combines specific plants for your garden that all look good together and bloom at different seasons. Try to avoid planting two different groups of plants next to each other that bloom at the same time. Those groups will leave a larger hole in the landscape.   

Example: nine coneflowers (pink) with five little bluestem ‘Twilight Zone’ (blue) planted next to seven Rudbeckia ‘American Gold Rush’ (yellow) which is planted next to three Aster ‘Raydon’s Favorite (purple).

Your pattern can be continued or another set of seasonal plants can be incorporated into the design. This is also a tier in the overall design. They are all about the same heights. Plant something taller behind and shorter in front of these perennials.

Succession planting is very rewarding, and these simple techniques should guide the process. Again, take time to acquaint yourself with the life cycles of wildflowers and grasses. The more you know the easier it will be to combine them according to bloom time. Succession planting is something that we all respond to, and brings the garden together visually.

Keystone Natives for the Food Web: Part 3 – Shrubs

Over the past few weeks, we have been listing native wildflowers that support the food web. Because many species of insects have suffered significant declines, any help we can give them will make a real difference in their life cycles. Our goal should be to provide habitat for the largest possible number of insects, pollinators and other wildlife. On that theme, here is a list of native shrubs to aid the food web.

Prunus

This diverse genus includes: sandhill plum, dwarf sand cherry, chokecherry, plum, and wild plum. These spring blooming shrubs attract many species of insects, and their fruit later in the season is a favorite of wildlife, including birds. 

These plants support over 450 Lepidoptera species, including Eastern Tiger Swallowtail, Coral Hairstreak, Striped Hairstreak, Red-spotted Purple, Cecropia moth, Promethea moth, and Hummingbird Clearwing. 

Sandhill plum-Prunus angustifolia Photo courtesy of Craig Freeman

Not all of these shrubs are garden worthy because of their spreading/suckering root systems and size. My preference would be to relegate many of these to the outskirts of my property so they can comingle with each other and form a nice thicket. 

Prunus besseyi ‘Pawnee Buttes’s is a nice small shrub with excellent characteristics.

Side note: The black cherry (Prunus serotina) is a 35-45 foot tree with fragrant, pendulous flowers that burst open in spring, resulting in loads of fruit cherished by wildlife.  This is one of the top choices among woody trees for its exceptional support of wildlife. 

Dogwoods

Dogwoods support specialist bees, generalist bees and over 100 caterpillars. This too is a diverse genus of varying heights, forms and textures. These spring/summer blooming shrubs or small trees attract aphids, beetles, flies, grasshoppers, sawflies and wasps. The fruit are eaten by birds. Many species form thickets or have dense branching that provides shelter as well. 

Of the native species, the Redtwig Dogwood is the most common.  Its red and yellow stems stand out in the winter landscape. Cultivars include ‘Cardinal’, ‘Arctic Fire’, Arctic Fire Yellow’, and ‘Winer Flame‘. 

Other dogwoods worth mentioning are Cornus amomum ‘Red Rover’, Cornus drummundii (rough-leaf dogwood), and Cornus racemosa

Flowering Dogwood (Cornus florida) is difficult to grow in our area because most cultivars need acidic soil. They are more common in southeast Kansas and into the Ozarks. If you are lucky enough to see these bloom in the wild you will be awestruck. They are one of the most conspicuous and attractive flowering trees in our area. 

Rough-leaf dogwood bloom

Viburnum

Kansas is home to two viburnums, Blackhaw Viburnum (Viburnum  prunifolium) and Rusty Blackhaw Viburnum (Viburnum rufidulum). They can be found in the wild, east of Wichita and into southeast Kansas. The creamy-white blooms in the spring attract all sorts of pollinators. Fruit in the late summer into fall is the first choice of birds. These are large shrubs or small trees that ultimately reach 10-12 feet tall and each has attractive fall color. 

There are hundreds if not thousands of viburnums and viburnum cultivars. A couple others worth mentioning are ‘Allegheny’ which has semi-evergreen foliage and Viburnum dentatum cultivars (Blue Mufffin, All that Glitters, and All that Glows) with their abundant fruit displays. 

Blackhaw Viburnum fruit-Viburnum prunifolium

Other shrubs to consider:

  • New Jersey Tea – Ceanothus americanus
  • black chokeberry – Aronia melanocarpa
  • Willows, Salix sp. – (#1 plant supporting bees)
  • Pussy Willow – Salix discolor
  • buttonbush – Cephalanthus occidentalis
  • elderberry – Sambucus canadensis
  • eastern ninebark – Physocarpus opulifolius
  • St. Johnswort – Hypericum densiflorum
  • spicebush Lindera benzoin
  • swamp rose – Rosa palustris
  • winterberry – Ilex verticillata
  • Witch-hazel - Hamamelis virginiana
  • Inkberry – Ilex glabra
  • Deciduous holly –Ilex decidua
  • Winterberry – Ilex verticillata
  • red chokeberry - Aronia arbutifolia
  • Fragrant Sumac – Rhus aromatica
  • Eastern Ninebark – Physocarpus opulifolius
  • Fringetree – Chionanthus virginicus
New Jersey Tea, Ceanothus americanus

Among woody plants, these shrubs will add much diversity to your landscape and attract a diverse set of wildlife. By offering abundant food sources to insect and wildlife throughout the growing season, you will naturally expand what you see in your garden. We must consciously consider plants that fit both the insects’ needs and our longing for garden beauty. We can have the best of both worlds. 

Side note: Of all plants studied by Doug Tallamy, he found that oaks support the most caterpillars. Obviously, these are not shrubs, but rather large trees. Oaks must be one of your first choices when considering shade trees for your landscape. Recommended trees of south-central Kansas.

Mighty Burr Oak ready for spring and all those caterpillars.