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.

Landscape Design Principles: Plant Placement, Proportions and Scale

Posted on March 20, 2019 by Scott Vogt

Plant placement, proportions and scale – these three elements of a successful design are really straight forward, but often overlooked. They hinge on a certain level of understanding regarding plant height and spread at maturity. These design principles also require you to incorporate clusters, sweeps and groupings of plants that look natural together with a succession of bloom all through the year.

Plant Placement

When I start a design, I think about where the bed is going to be viewed. Is it from the street? Is it from the living room? Will I want to view it from different vantage points? This helps me frame the landscape. For instance, if you have a foundation planting, you would obviously put the taller plants in the back working down in layers to the smaller plants along the border/edge of the bed. If you were designing an island planting that would be viewed from both sides, I would plant the taller plants in the center with shorter plants spaced around the central focal point. It seems obvious, but we don’t always think about sight lines.

Another element of effective plant placement is bloom time. With native plants, you need to think about succession of bloom. You want to have plants coming into bloom and going out of bloom throughout the year. Don’t plant two spring blooming plants next to each other, but rather plant a spring blooming wildflower next to a grass or later season blooming wildflower. By incorporating plants that have color at varying times, you have something interesting happening year-round.

Proportion and Scale

I don’t always observe or think about proportion and scale until it is too late. The beds you design and the plants you include should look appropriate with the size of your home or the size of the flower bed. As a general rule, I include plants that are no larger than half the bed width. For instance, if your area is eight feet wide, try to find plants that are no taller than four feet. Sometimes, smaller beds are all we have to work with, such as the small area between a sidewalk and your home. Maybe it is only three feet wide. Don’t try to put plants that are four to five feet all in that space. It will flop onto the sidewalk and look out of place.

*Compass Plant is a beautiful wildflower that gets eight feet tall. It is out of scale in a smaller space. Give it room to gr*ow.

If you are starting from scratch, lay out a garden hose away from your foundation. Take note of the gentle curve around your home. I like to have at least four to six feet of width to work with. That gives you so many more plants to choose and include in your design. On the corners, I like to give myself a little more room of maybe up to 10-12 feet. This allows larger plants to be combined to soften the corner. You probably have a picture in your mind of what you want to frame the views and keep it simple. A garden that is too busy and out of proportion detracts from your home rather than complementing it.

Again, it is important to know how tall and wide each of the plants will grow. I like to include plants that will fill in the spaces available to them. Really think about the plants you want to have near sidewalks, windows, patios, and porches. You don’t want to be continually cutting them back when they have outgrown the space.

It sounds so simple, but these are the design principles I struggle with the most. There is so much to consider with each design, from site analysis, plant habit and bloom times, textural elements, and so much more. We can’t have it all, but a basic understanding of scale, proportions and plant placement will help you create a successful design. Now is the time to get started. If you need help, we will be happy to work with you during our remaining Native Plant School classes or at the FloraKansas Native Plant Festival.

Landscape Design Principle: Lines

Posted on March 6, 2019 by Scott Vogt

A native plant design is a highly subjective project. The plants you like may not be the ones I would choose and vice versa. Your garden area is unique to you. Sun, soil, moisture conditions can vary as well. The canvas you are painting on will look distinctly different than my artistic design. As we strive to create a sense of place in our landscapes, our medium is the land. Even though each garden is one-of-a-kind, there are a few design principles that we all should follow. Over the coming weeks, we will discuss some of these design principles.

Today, we will be tackle lines within the garden.

Lines should be used to draw people in and through the garden. They appeal to the senses. They lead you through the garden and help frame views we see or don’t want seen.

Straight lines

Long, straight rows of plants can be rather formal. They are structural, often symmetrical and lead the eye directly to the focal point like the front door. Straight lines can be boring if you don’t cluster plants and repeat patterns. The strong straight line of a fence can be softened with a sweeping curved edge or accentuated with parallel plantings that run the length of the fence.

Vertical lines

These lines move you up and down in the landscape. Taller trees, larger structural features such as an arbor should make your eyes go upward. They make the space feel larger and help enclose the space.

Horizontal lines

Just like vertical lines lead your eye skyward, horizontal lines lead your eye along the ground plane. These low lines help define the space and work to tie everything together. Rock walls, edging with plants or stone, hedges, or a clean line between turf and plants are examples that create these intentional low lines.

Curved lines

Curved lines look intentional and informal. Gently bending lines can be used to lead people slowly around a corner to an architectural feature or element such as a bench, garden shed, arbor or vegetable garden, which adds mystery and intrigue to your garden space. Curved lines can help dissolve rigid straight lines of a walkway, fence, house or other structural feature. Curved lines fit better in a natural asymmetrical design using native plants. I like to place a garden hose on the ground to help me visualize these meandering lines. As you step back to look, you are able to move the hose to create the effect that is most appealing before you break ground on your new garden.

Be intentional in grouping plants.

No matter the lines you use in your landscape, plants obviously play a key role. Formal and informal looks can be achieved with the use of certain plants grouped together or spread apart. Cluster plants together for more visual appeal. Repeat structural plants like native grasses and incorporate filler plants throughout the design that bloom at different times during the year to draw you into the garden and through the garden. Plants that spill over onto the straight lines of a walkway soften the edge. The possibilities are endless because there are so many plants to choose. How you use lines will distinguish your design from others. Really think about this important design principle and what lines you want to use.

Next time, we will talk about plant placement, proportions and scale.

How to Increase the Value of Your Prairie Garden

Posted on January 23, 2019 by Scott Vogt

Prairie gardens have become increasingly popular over the past ten years as homeowners and businesses seek to directly reverse the trend of prairie degradation. Using prairie plants in the landscape is one way you can implement small-scale conservation and stewardship practices and become a part of a growing patchwork of prairie gardens in the Great Plains region.

These patchwork prairies will not replace what has already been lost, but can begin to help raise awareness about conserving any remaining prairie remnants. Hopefully, we will no longer take for granted the prairies around us and work toward managing and conserving this landscape that is quickly vanishing.

You may ask yourself, “Can a backyard prairie garden really make an impact? How do I increase the value of my prairie garden?” The value of a small prairie garden seems minuscule compared to the large prairie tracts that are being lost each year.

Here are a few things you can do to maximize the impact of your small patchwork prairie garden and further your backyard conservation efforts.

Plant a diverse prairie garden

As you design your garden, look to include as many different species as possible. It is important to have a succession of bloom from spring through fall. Include some of the native grasses to provide vertical elements and alternative textures. These elements will support and frame some of the native wildflowers. Your garden can become a conversation starter within your neighborhood. Your neighbors’ perspective may shift as your intentionally “wild” and slightly “messy” garden creates habitat for wildlife and pollinators. People will notice the difference. Your garden, along with many other prairie gardens throughout neighborhoods, will add value to the environment and broaden the conversations we can have.

*Fall Blooming Asters with Little bluestem*

Connect with where you live

For many of us, we take for granted the prairies around us. Even though we have some of the largest tracts of prairie like the Flint Hills at our doorsteps, we often don’t see the peril they face. So in light of these difficulties, it is imperative that we use native species from our region. Create a sense of place by incorporating as many plants of a local eco-type as possible. These plants are adapted to your climate and soil. Cultivated varieties and hybrids give us consistent characteristics and qualities. However, they often lack the same landscape value to pollinators as the true species and are most likely not from your region. Choose your plants wisely to maximize the impact they have to the garden aesthetic and the wildlife that need them.

Create an immersive experience

Layers of plants from different perspectives or vantage points will offer you the most enjoyment from your garden. As you are drawn through the landscape, surrounded by lush plantings, you can enjoy the changes from season to season. Sunlight, texture, color, and varying heights combine to provide unique encounters with your landscape. The value of these experiences for your body and soul cannot be measured. Quiet reflection can calm you after a hard day or bring you some perspective in your life.

*Early summer in the Kansas Wildflower Exhibit*

Most gardens will never be as perfect as we want them to be, but they still have value for us and our environment. They are valuable to wildlife and pollinators. Valuable for the broader conversation about stewardship of the land. Valuable to us as we become more aware of the role we can play in conservation and as we develop a relationship with the land.

Don’t sell short the importance of the prairie, no matter how big or how small. Every step taken, every wildflower or grass propagated, every patchwork prairie garden planted has value.

What is the Key to Native Plant Happiness?

Posted on April 11, 2018 by Scott Vogt

One of the questions we get every year at the FloraKansas Native Plant Festival, is “why didn’t my ___ come back this year?” It is a great question. Every year at the Arboretum, we ask the same question with some of the plants we establish and want to grow. I wish there was a right answer for every situation and every scenario, but every landscape is unique. Here’s the hard truth that many gardeners don’t often want to hear: the key to native plant happiness lies in identifying this uniqueness and finding the right plants for your plot.

Coneflowers blooming in the lush prairie garden

Match Plants to Your Site

Your landscape is a micro-climate all its own. The soil, sun exposure, orientation to your house, root competition from trees, and many other factors make your garden special. Even your neighbor overwatering their lawn can impact what plants grow best in your scene. There are hundreds of factors that relate to the happiness of your plants and whether or not they will thrive.

The most critical step when establishing your native plant garden is matching the plants with your site. Sometimes I want to try a certain plant in a certain spot that has no business being planted there. I have done it too many times to mention and the result is always the same. I am left holding the hand of a struggling plant that would be much happier someplace else. In the end, I either move it or lose it.

Summer blooms of Kansas gayfeather and gray-headed coneflower

Do Your Homework

If we are honest, I think we have all planted before preparing. The wilting plant in the flower bed is a constant reminder to me that I didn’t do my homework. Look at your landscape. Is it sunny or in the shade? Is the soil clay or sand?

Become familiar with prairie plants that grow in similar situations and evaluate the elements that will impact their survival. Choose plants that will thrive in the micro-climate of your yard. Sun-loving native plants need at least 6 hours of direct sunlight to grow happily. If your flower bed receives less than 6 hours of sun, look at more shade-loving natives.

A thriving landscape begins with matching plants to your one-of-a-kind area. For a lower-maintenance garden, choose plants that occur in the same or similar prairie climates. Anytime you stray too far off, the plants don’t flourish and they require more effort to keep alive. Planting a swamp milkweed on a dry hill or a Missouri evening primrose in a bog will never work.

Butterfly milkweed on a well-drained slope

Learn From Your Mistakes

Good gardeners have lost their share of plants over the years, but what makes them good gardeners is that they learn from their mistakes. With lots of trial and error under their belts, they/we should make better choices…in theory at least.

Other design elements such as succession of bloom, patterns, year round interest, heights, and visual elements become less important when your plant is unhappy in its current location. You must get the right plants in the right place and the other elements will come much easier. A healthy garden begins with a connection to your landscape personally. As you watch and learn what your landscape needs and what it can sustain, you will be able to link the appropriate plants to the location. This important step in the design process allows you to spend more time enjoying and less time “working” in your garden. We all want that from our gardens.

Just one more thing…

Sometimes plants, through no fault of our own, defy all of the above-mentioned rules and simply don’t return. Even in the prairie, plants are ephemeral and rely on self-seeding to continue to grow in an area. As you become more familiar with native plants (and I’m still learning too), you will be able to identify these species. It is their nature to be short lived. True native coneflowers have this characteristic. They are worth planting, but may need to be supplemented with new plants from time to time to keep the area full.

Pale coneflower

Planting for Pollinators

Posted on July 5, 2017 by Scott Vogt

Last week, I was visiting with someone about pollinators or the lack thereof. It seems that we had an initial flush of monarchs and other beneficial insects earlier this spring, but since then many of the pollinators have become scarce. There are beautiful wildflowers in bloom but very little insect activity. We have all seen the dramatic statistics tracking the plight of pollinators and their losses, so what is happening?

That is a difficult question, because there are often a combination of factors that are associated with the demise of many of the pollinators we take for granted. Pollinators have been impacted by habitat loss, pesticides, pathogens, mites, invasive species of plants, parasites and an erratic climate. Different species are affected by different forces, but overall the result is the same, fewer pollinators.

So what can we do to help pollinators? Here is a list of ways that any gardener can have an impact.

Plant Pollinator-Friendly Plants

Certainly, milkweeds are the best wildflowers for attracting monarchs to your yard. We have seen this throughout the Arboretum as caterpillars munch on the milkweed leaves. Other blooming wildflowers offer their nectar to a host of insects. The wildflowers are the buffet. I like to have members of the aster family such as coneflowers, asters, goldenrods, blackeyed susans and blazing stars. (Peruse our native plant list and sample landscape designs for some inspiration.)

Tiger Swallowtail butterfly on a Gayfeather. Photo by Janelle Flory Schrock.

Plant for All Life Stages

We recommend planting wildflowers that bloom at different times of the year. A mixture of wildflowers coming into bloom and going out of bloom throughout the year provides a ready food source for adults and their larvae. This approach mimics the natural prairie and the changing seasons. Maybe plant some dill or Zizia sp. for the swallowtail butterfly caterpillars.

Monarch caterpillar on milkweed. Photo by Brad Guhr.

Provide Habitat

When you design your landscape, remember to layer trees and shrubs along with wildflowers and grasses. These plants provide shelter from the wind along with nesting sites and food for birds, butterflies and bees. This created habitat is a safe environment for pollinators to find all they need including food, shelter and water. Even a small garden can have a tremendous impact.

Bee Hotel. Photo by John Regier.

Provide Water

We all need water for survival. Pollinators need it too. A clean source of water such as a birdbath, basin, or hollow stone is enough water for pollinators. These features also provide landing spots so that pollinators have a perch. Here are some great plants to complement your water feature.

Pearl Crescent Butterfly. Photo by Dave Osborne.

Reduce Chemicals

There is growing research on the detrimental effects chemicals have on pollinators. Any time we can reduce or eliminate the use of chemicals in the landscape, we are impacting wildlife in a positive way. Allow insects to control unwanted pests. Be willing to accept a few damaged plants, knowing that by not spraying you are saving much more in the long run.

Bumblebee on Echinacea purpurea. Photo by Janelle Flory Schrock.

Learn About the Plight of Endangered Pollinators

There is so much to learn about each type of pollinator. When are they out in the garden? What do they need to complete their lifecycle? Where do they migrate or how do they overwinter? We have so much to learn about these important insects. (One good resource for this is this book, by Heather Holm, which we often carry in our gift shop. Check out MonarchWatch.org or the Xerces Society for Invertebrate Conservation for great resources.)

Gray hairstreak on Eryngium leavenworthii. Photo by Brad Guhr.

Pollinators live perilous lives. Their very existence hangs by a thread. We need them for the food we eat. Plants need pollinators for their survival. So much depends on these tiny little insects. As gardeners, we can support the life cycles of pollinators by including a wide variety of plants in our landscapes. Native wildflowers are the best option to help them prosper. They need our help and you can be part of the solution. You will be amazed at how many pollinators you will see when you introduce just a handful of wildflowers to your landscape.

How to Create a Beautiful and Sustainable Garden

Posted on April 26, 2017 by Scott Vogt

With growing season and FloraKansas on the horizon, we have been asking a few questions of ourselves over the past few months about native plants. Certainly, we have seen the benefits of using native plants in the Arboretum and at our homes, but what would it take to convince someone to install them in their yard who has never tried them or is unfamiliar with them? What would it take to begin to change their minds?

We keep coming back to this idea of beautiful AND good. Aesthetics are important and we all want attractive landscapes, but so is this feeling that what we are doing is good for everyone and everything.

Beautiful orange flowers of Butterflyweed (Asclepias tuberosa)

It can be intimidating to change the way you garden or landscape. Choosing plants just because they are visually appealing simply isn’t a good enough reason anymore. Creating a habitat using plants that are adapted to your site is a far better approach to landscaping. Designs that have attractive combinations of wildflowers, grasses, shrubs and trees may initially capture our imaginations, but more and more people are wanting these plants and their landscapes as a whole to provide additional benefits. Our gardens must now not just look good, but also do double duty to provide for pollinators, attracts birds and other wildlife, develop habitat and positively impact the environment.

The evidence that making such a change will really make a difference in our lives and in our gardens begins with the first native plant. I have seen it time and again – if you plant them, they will come to your garden. If you plant milkweeds, the monarchs will find them; if you plant penstemons, the bumble bees will find them; and if you plant asters, a flock of pollinators will cover them in the fall. It sounds so simple, but it is indeed true. These plants need the pollinators and the pollinators need these plants. The significance of planting your first wildflower can be both beautiful and good.

If you want to be part of the solution and do your part for nature by reducing water usage and eliminating chemicals, attracting countless forms of beneficial wildlife including butterflies, hummingbirds, and pollinators, cleaning storm water runoff, and having a beautiful landscape, start with a few native plants. Each of us CAN have a positive impact. We are stewards of these ecological, environmental, and sustainable gardens. An aesthetically pleasing landscape can also be functional and serve a variety of purposes.

Steps to a beautiful and sustainable landscape

Home landscapes can be transformed using native plants so that they are sustainable, easy to maintain, and beautiful. To start planning your native plant garden, be sure to attend our FloraKansas Spring Plant Sale and look over our 2017 plant list.