Native Grasses for Color, Movement and Structure

Posted on March 31, 2021 by Scott Vogt

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.

**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.

*Cheyenne Sky Switchgrass with Rigid Goldenrod*

**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.

**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’.

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 with Native Kansas Oaks

Posted on March 25, 2021 by Brad Guhr

*Filtered light coming through a stately open-grown burr oak*.

There are many appealing reasons to consider landscaping with native Kansas oaks. Oaks are

long-lived with strong branches,
can grow to be large and stately,
provide welcome shade from the hot Kansas summer sun,
allow some filtered light to pass through to allow growth of understory vegetation, and
enhance the wildlife diversity in any landscape by attracting insects.

Native Kansas Oaks

Kansas is predominately a prairie state. Fire and grazing have helped keep grasses and wildflowers as the dominant form of vegetation for thousands of years. Kansas does, however, get enough precipitation to support trees, especially many drought-tolerant species of oaks. And when they are not being burned or grazed down to the ground on a regular basis, they can thrive here.

With the Rocky Mountain rain shadow influencing the precipitation map for Kansas, we have increasing bands of precipitation moving from west to east across the state.

Trees generally need more water than prairie grasses and wildflowers. Therefore, it is understandable that eastern Kansas climate is most hospitable for growing trees. The following Küchler Vegetation Map of Kansas confirms the association between greater precipitation and the historical presence of trees by the location of oak-hickory forests, oak savannas, and other timbered regions in the eastern part of the state.

The trees that thrive throughout eastern Kansas may also be able to grow further west into Kansas, but will be limited to locations near streams or urban landscapes where they can receive supplemental irrigation.

Using the fantastic recently published book, Trees, Shrubs, and Woody Vines in Kansas by Michael Haddock and Craig Freeman, I compiled the following table of the oaks native to Kansas. I have listed the 12 native oak species in order from most to least common in Kansas. I did this to serve as a guide to the species that generally have the greatest tolerance to drought conditions and that are therefore more likely to succeed even in the drier parts of the state.

Attracting Wildlife

Regarding the benefits of oaks I provided in the introduction, I want to expand a bit on the benefits of attracting wildlife.

Filtered light sustains understory vegetation

Oaks in general and especially more drought-tolerant oaks like burr oak allow more light to filter through its leaf canopy to the understory than other tree species such as elms and maples. As I describe briefly in a post about a local, large burr oak tree, burr oak savanna plant communities of Eastern Kansas were historically able to support diverse arrays of grasses and wildflowers under their canopy that promote a healthy ecosystem of biological diversity. Urban folks can follow this model and grow prairie-like native plant gardens under the canopy of oaks. This also helps explain why it is easier to grow turf grass in the filtered light conditions under an oak than it is under the shadier understory of an elm or maple.

Oaks – the best trees for supporting wildlife

Professor Doug Tallamy in the Department of Entomology and Wildlife Ecology at the University of Delaware is a big proponent of using native oaks to attract wildlife. His book Bringing Nature Home: How Native Plants Sustain Wildlife in Our Gardens makes a strong case for using oaks to attract caterpillars, and subsequently birds that feed caterpillars to their young, to enhance the biological diversity of a landscape. His research shows that the oak genus (Quercus) attracts more caterpillars to its leaves, flowers, bark, acorns, and roots than any other genus of trees. In fact, this genus is so important to Tallamy that his most recent book The Nature of Oaks: The Rich Ecology of Our Most Essential Native Trees focuses entirely on the subject.

Five Favorite Oaks

While I think there are appealing components to all 12 of the native Kansas oaks, I have narrowed my focus for the purposes of this post to promoting five favorite oak species.

USDA maps denote the natural range of each species. A given tree may still thrive in say an urban area outside of this range when offered wind and drought protection from structures, other trees, and/or supplemental irrigation.

This 55′ wide by 45′ tall burr oak outside my office window is great example of how this species takes a wide-open stance when grown in full sun. The root structure cross-section drawing pasted proportionately below this tree was found in the Nebraska Conservation Bulletin Number 37.

Burr oak savannas were part of the focus of my graduate research and I simply love the majestic, strong-branched open-grown shape of this species. The shape and distinct look of a mature Q. macrocarpa specimen in winter is as interesting to me as its leafy green look during the growing season. It is bimodal in its moisture distribution, meaning it can survive in both dry upland conditions as well as low floodplain conditions. Thick, gnarly bark makes this tree more fire tolerant than most, and when top-killed, its taproot allows it to immediately re-sprout. The large acorn fruits (hence the Latin name “macrocarpa“) are food for many insects, mammals, and birds (e.g., turkeys and wood ducks). To appreciate the value of a burr oak to wildlife, click on this Illinois wildflowers link and scroll down to the impressive list of “faunal associations.” Burr oak leaves turn yellowish-brown before dropping in the fall.

The attractive ashy gray bark, toothy margined leaves and stately round shape of the drought-tolerant chinquapin oak make it an appealing landscaping tree. One-inch sweet acorns are a favorite food for many birds and mammals and the leaves turn yellow-orange to orangish-brown before dropping in fall. This species prefers well-drained soils but tolerates a variety of soil textures and moisture regimes.

Dwarf chinquapin oak only reaches a mature height of approximately 20 feet and certainly can be used in different landscaping scenarios than any of the four other medium to large landscaping trees recommended here. You may use it as a featured shrub or planted with many to form a screen. This species prefers sandy or clayey soils whereas the larger Q. muehlenbergii does best in calcareous soils. In spite of its small size, dwarf chinquapin oak can produce large quantities of acorns which along with the leaves and bark provide food for numerous species of insects, birds and mammals. This oak is known to produce underground runners to spread clonally.

Black oak is named for its dark bark color at maturity. It has a deep taproot with widespread laterals which make it a very drought-tolerant tree that is adaptable to a variety of soil types. It does especially well in sandy soils. As described for other oak species, black oak provides food for numerous insects, birds and mammals.

Shumard oak is a popular landscaping tree because of its strong branches, long life and red fall color. It is adaptable to a variety of soils and its acorns provide food for various types of wildlife including insects, birds, and mammals. Although its natural environment is along streams in Eastern Kansas, it is tolerant of drier areas further west in protected urban areas. A shumard oak I planted in my yard loses its leaves late fall, by around Thanksgiving.

Things to Think About

Tree size/location

When locating a tree, leaving room for the eventual size of the mature tree will save you or future caretakers time and money. Conflicts between growing tree branches and buildings, utility wires, city code street clearances, and branches of other trees can lead to tree trimming headaches, so consideration given to a tree’s height and spread is important. Also, the closer a tree is to a sidewalk or driveway, the more likely its roots are to alter the grade of and contribute to the cracking of that concrete.

How long will it hold its leaves?

Some oaks lose their leaves in fall, but others hold onto them until spring. I can think of a couple of reasons this may be important to you. If you like to do your leaf raking in fall, don’t choose an oak that holds leaves till spring. If you want your oak to cast shade in summer but not winter, be sure to choose an oak that drops its leaves in fall. For example, this may be an important consideration for a tree that shades a house in summer, but allows solar panels to work in the winter.

Oak leaves are slower to decompose

Know that oak leaves have higher tannin content than many other tree species, and therefore, take longer to decompose. I like to use all my tree leaves for garden mulch and since the oaks I’ve planted in my landscape are all pretty small still, this has not been a big concern. However, if you compost your leaves or have heard the myth that tannin-rich oak leaves will make your soil more acidic, read this article.

Slower growing trees still provide rewards

A common complaint I hear about oaks is that they grow too slow. Therefore, folks may opt for the short-term gain of quick shade provided by a poplar or silver maple instead of a longer lived oak. A poplar lifespan may be 30-50 years, a silver maple 50-100 years, and an oak 150-250 years. But what you gain in quicker shade with the poplar and silver maple, you give up in durability, attraction to wildlife, and passing along quality trees to future property owners. The above recommended oaks all would be considered slow to moderate rate growing trees. Do know that you can increase the growth rate of an oak with mulching, supplemental water, and fertilizer. Maybe it is the skewed perspective of an oak lover, but I would think that oaks even improve property value. And remember, a tree is planted for the next generation as much as it is for you.

Landscaping to Attract Pollinators

Posted on March 17, 2021 by Scott Vogt

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.

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.

New Native Plants: Part II

Posted on March 10, 2021 by Katie Schmidt

This is the second post in a two part series exploring new plants available at the spring fundraiser. After 22 years of Florakansas, we are still finding new garden-worthy natives to offer our community, and the commercial horticulture industry is always introducing new plant varieties to try.

Allium ‘Lavender Bubbles’

Ornamental onion is a landscaping favorite because of its tidy habit and pollinator-friendly blooms. We will have the native species A. cernuum and A. stellatum available, but when you need a bit more purple punch ‘Lavender Bubbles’ is the way to go. This variety blooms later in the summer than the well-loved ‘Millennium’, and has darker blooms.

Ephedra regliana

*Ephedra regalia, known as joint fir, is a diminutive ancient plant that adds some evergreen whimsy to a rock garden or border planting. Photo by I, James Roberts, CC BY-SA 3.0 via Wikimedia Commons.*

Tolerant of alkaline soils and extreme drought, this plant can be found growing wild from Kyrgyzstan to China. A relative of ancient conifers, its showy red fruits develop in late summer. It absolutely demands good drainage, poor soil, and full sun. It would fit right in with a cactus garden or desert aesthetic.

Eupatorium ‘Prairie Jewel’

Eupatorium altissimum is a native Kansas plant that does not get the credit it deserves. It is seen as a tall, gangly plant with small, unimpressive white blooms. I have begun to appreciate it more and more as a drought tolerant back drop plant; something to grow at the back of the garden to add height and greenery. I call the flowers ‘baby’s breath of the prairie’ because they are so useful in bouquets. The ‘Prairie Jewel’ variety has striking leaf coloration that keeps it interesting, even when not in bloom.

Calamintha nepeta var. nepeta

Calmintha nepeta var. nepeta blends into many garden styles and makes a lovely addition to the perennial garden. Photo by I, KENPEI, CC BY-SA 3.0 http://creativecommons.org/licenses/by-sa/3.0/, via Wikimedia Commons

This is a plant I am very excited to try out in my own garden. Its white blooms and puffy habit make for great filler in weed-prone spaces that would benefit from dense cover and competition. Native to Europe, this mint family member carries its well-known pros and cons: it can be aggressive if left to spread unchecked, but it is beloved by pollinators.

Remember, members get first pick of the plants through pre-order services and our special Members-only Day on April 22. If you see some new plants here you just can’t live without, consider joining our growing membership of nature lovers! These plants and many more will be available to non-members April 23-26.

Succession of Bloom

Posted on March 3, 2021 by Scott Vogt

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.