Stumped: Reimagining a garden after tree loss

Ten years ago, my spouse and I purchased our first home in Central Kansas. The backyard was dominated by a large American Elm tree that had miraculously, and with a lot of help from a local arborist, survived the bout of Dutch Elm Disease that had taken nearly all of the American Elms in town in the 1990s.

In June of 2013, an aged American Elm tree beautifully shaded our backyard.

What this meant was that, like many Kansas homeowners, we had a large area of dry shade to contend with. Informed by my spouse’s childhood experiences growing up in the bush of South Sudan, we were not inclined to water our lawn just to maintain the status quo. So, the challenge was, how do we increase biodiversity in this backyard without using supplemental watering? We were stumped.

We tried a few things in the deep shade of the tree – transplanted spiderwort, river oats and columbine from a friend. And although these species hung in there pretty well, they certainly did not thrive. Ideally, they would have liked a little more sun and a lot more rain.

Here at the Arboretum, in our list of frequently asked questions at FloraKansas Native Plant Days events, “Which Kansas native plants will grow well in dry shade?” rises to the top. Unfortunately, the answer is “Hardly any.”

In a prairie ecosystem, trees will only flourish along creekbanks or near another water source. The garden condition “dry shade” is a human-created environment that simply does not exist in nature. For humans, and particularly for those of us who are relatively new to gardening with native plants, this is often a difficult reality to process and to accept.

Over the years, several major ice storms and wind events have weakened the structure of the tree. The final blow came in August of 2021. It was time to have the tree removed.

Another reality that was difficult for us to accept was that the elm tree was in an irreversible decline. The health of the tree had been compromised by an ice storm in 2007. Slowly over time, the rotting that had begun after that first injury made the elm more susceptible to being damaged again. As it became clear to us that this tree was in a death process, we focused our efforts on developing the front yard and enjoyed the shade while we could.

After the tree had been removed, we needed to reimagine what our backyard was going to be.

In the fall of 2021, we finally admitted to ourselves that the tree needed to be removed. We allowed ourselves a year to sit with the new reality of a full sun back yard. We left the stump and planted it with yarrow, little bluestem and soapwort. We have also contemplated growing mushrooms in the stump. Over time, we will watch the stump disintegrate and return to the earth. For now, it provides a lovely focal point.

In the raised rock garden beds surrounding the stump and along the south fence, we have filled in with plants that prefer well-drained soil, including butterfly milkweed, Missouri evening primrose, blue flax, soapwort, and several adaptable creeping groundcovers. Also, I couldn’t help but try my guilty pleasure plant that would prefer to be at higher elevations, pineleaf penstemon.

In a test area that was formerly in deep shade, we have seeded buffalograss and encouraged it to spread. In retrospect, I wish we had done this to the whole lawn area right away, because this spring, much of the former fescue lawn has mostly been populated by dandelions, wild lettuce, henbit, clover and spurge. Nevertheless, we are motivated to continue to populate the back yard with sun loving prairie plants.

The lawn is currently a polyculture of warm season grasses and annual weeds (please don’t judge!), but we are on our way to establishing buffalograss and determining where we would like to plant native perennials.

I know there are likely many things we could have done so much better. Do I have regrets? Definitely. Could we have saved that elm tree by trimming it every year? Probably. In stewarding this small piece of the land, we are far from perfect. But honestly, in this process, I’ve learned that the land is more forgiving than humans are, as long as you don’t try to bend it to your own will. If you listen and observe your garden, over time, it will tell you how it wants to be. It will allow you to make mistakes, and then correct them. It will teach you to view the cycle of life in new ways. And if you can hold back from trying to control it too much, you will be rewarded by new and unexpected discoveries on a daily basis.

Tree loss at the Arboretum

One of the hardships of being a gardener is the loss of a long established tree. It is no different here at the Arboretum. We have lost a few trees that were planted at the founding of the Arboretum. The loss of these large specimen trees leave a huge hole in the landscape that will take another few decades to fill.

Austrian Pines

We continue to lose a few pine trees each year. All of our Scotch pines are gone due to pine wilt. We are now losing larger ponderosa and Austrian pines. We have a tree that is over 40 years old that was green last fall but is now totally brown, dead in less than six months. This could be due to a number of factors such as drought (although we watered it last summer into the fall), or some sort of tip blight. We believe this browning is blight. We are removing these trees as they die, which is heartbreaking.

Austrian Pine turning brown from the bottom to the top

Southwestern White Pine

This was one of the evergreen trees I recommended to plant a few years ago. It is no longer a viable alternative to some of the other two and three needle pines that have been lost to disease. We have lost a row of these due to pine wilt. Pine wilt causes a rapid decline of a pine tree in just a few months. The infected trees must be removed and burned to stop the spread.

River birch

In our parking lot median, we have slowly been losing an original row of river birch. Admittedly, this was not the ideal location for river birch. We were watering these trees almost weekly in the summer since they are not very drought tolerant and have shallow roots, which leaves them stressed in the heat sink of the parking lot. I see this same river birch scenario in other landscapes with river birch planted front yards and drier areas. Often times, these trees are struggling just as ours were unless they are receiving frequent irrigation through the summer. As their name implies, they grow best in wetter areas along streams, swales and ponds. We are replacing our river birch with a variety of deeper rooted trees such as oaks.

River Birch in parking lot median

Autumn Purple Ash

What a big surprise this spring when this large white ash didn’t leaf out. One side has leaves, but the other side is completely bare. It has been infested with borers with have damaged the trunk, branches and stems. It showed no signs of disease last year. Even if I had seen and diagnosed the problem last fall, the treatment would not have been very effective. The result would have been the same. We are holding out hope that it will miraculously leaf out yet this spring. If not, it will need to be removed.

Autumn purple ash struggling to leaf out

Pin Oak

It is well known that pin oaks suffer from iron chlorosis, which causes a yellowing of the leaves. Chlorosis in pin oaks is usually due to a deficiency of iron in the leaves. Iron is important for chlorophyll synthesis in plants, so when it is deficient, leaves cannot make chlorophyll, resulting in a yellow appearance. Chlorosis of pin oaks is typically associated with alkaline soil pH – pH greater than 7, which is common in our area. This iron deficiency eventually weakens the tree and stunts its growth. Trees can be treated by injecting iron into the trees or trying to change the pH of the soil. However, it is better to not plant these trees in our area. We are removing these trees and replacing them with varieties that don’t suffer from iron chlorosis.

Chlorotic Pin Oak that will eventually need to be replaced.

Bottom Line

Having trees in Kansas is a luxury, especially large long-lived trees that provide wonderful shade. Kansas weather – with its extremes-wet, dry, hot, cold, and wind – are all challenges for trees. The other thing to keep in mind is that our area was originally prairie. Prairie is what grew best here, with trees relegated to creek bottoms and wetter areas. So growing trees here will always be demanding and ambitious. Even if we do everything right regarding trees in the landscape, there is no guarantee that a tree will grow and thrive.

We will continue replacing and planting trees here at the Arboretum. I believe a diverse selection of trees – different from the trees we have lost – is the answer. We will continue to lose trees, because they are living organisms susceptible to all sorts of diseases and problems. But keep planting, folks!

Recommended trees and shrubs from Kansas Forest Service

Totally Tubular

Tube flowers occupy a special niche in the ecosystem. They cater to pollinators with especially long tongues, saving their nectar for the lucky few who can reach it. There are lots of tubular blooms at the Arboretum right now, so I thought we ought to take a tube tour and examine a few of my favorites up close.

Penstemon

With so many species to choose from, there is a Penstemon that’s right for everyone’s garden. Penstemon grandiflorus is a drought-loving species, shorter and with waxier leaves than its common, white-bloomed cousin Penstemon digitalis. Penstemon cobaea is the diva of the bunch: much showier and larger flowered, with flouncy pink bloom spikes that are more prone to falling over after heavy winds or rain (the floral equivalent of fainting onto a nearby chaise). But for all its drama, it is worth it for those huge, almost foxglove-esque flowers! All of them are a boon to hummingbirds in early summer.

Penstemon grandiflorus, pink tube shapes flowers on a reddish stem, airy and delicate looking.
Penstemon grandiflorus can range from white to light pink or lilac. It likes dry conditions and lean soil.

Honeysuckle

There is good honeysuckle and bad honeysuckle, and you should learn the difference! Invasive honeysuckle can come in two forms: bush or vine. Amur honeysuckle (Lonicera mackii) is the bush that has taken over woodlands and displaced many of our native species. It spreads by birds ingesting the berries then *depositing* them into new areas. Forests full of this stuff have decreased value for wildlife, and become an impenetrable monoculture and a maintenance nightmare. A look-a-like species, Lonicera japonica, is a vine with a similar flower. This too is invasive in our area, and can be found climbing trees and toppling fences. If you have these species on your property, please eradicate them and replace with a native honeysuckle like Lonicera reticulata — all the beauty of clustered, yellow tube blooms, but without the nasty invasive qualities. Or Lonicera sempervirens, a red flowering vine that grows vigorously and attracts hummingbirds. Both are drought hardy too!

Amur honeysuckle (Lonicera mackii) is a threat to our native ecosystems.
Lonicera reticulata blooms in May, and attracts many pollinators!

Amsonia (Common name: Blue star)


These small, star shaped flowers all cluster together to create a showy head of light blue in spring. But behind each star is a tiny tube! I’ve seen hawk moths, also known as hummingbird moths, flitting around these things for weeks now enjoying their nectar. Amsonia is easy to grow and likes full to part sun. Amsonia hubrichtii is thin leafed, almost needle-like in appearance while Amsonia illustris has a broader, glossier leaf. Both are hardy and can stand up to wind and drought, with excellent fall color.

Amsonia hubrichtii in fall color. Photo courtesy Walters Gardens.

Monarda

Monarda fistulosa flower, photographed by Brad Guhr

Also known as bee balm, this plant has a unique, pom-pom style bloom made up of individual flower tubes. In Kansas you will most likely find Monarda fistulosa growing wild, in ditches or near streams and ponds. Monard bradburiana is a shorter, slightly better behaved cousin. Both like full sun and medium soil moisture. Monarda didyma is a common eastern US species, and does well here if given a bit of extra water. I’ve seen lots of bees, butterflies, moths, and hummingbirds on this one so it gets an A+ rating for pollinator attraction.

A red variety of Monarda didyma shown with solidago (left) and a light purple Monarda fistulosa (right)

Tube-shaped blooms can be found everywhere if you start looking. They have a completely different structure than the classic radial flowers (roses, petunias) or composite flowers we are used to seeing (think sunflowers, echinacea, asters). The diversity of pollinators is as great as the diversity of flowers they feed on thanks to coevolution for thousands of years! Consider adding some tubular flowers to your garden, and enjoy their wacky, wonderful shape.