Leave The Leaves

Leaves are everywhere this time of year, and for good reason! Leaves have an important role in the ecosystem. Trees and the organisms living in and below them have evolved for millions of years together, working in sync to create vegetation and break it down in an efficient cycle. But most Americans don’t realize this, quickly raking the leaves away as soon as they fall on our precious lawns. Well, here are some facts that might change your mind and urge you to leave that rake in the garage!

The leaves of ‘October Glory’ maple are beautiful but my do they fall everywhere!

For the Love of Lawn

Most people rake leaves out of concern for their lawns. Rightly so, as a thick layer can damage turf grass. Leaves staying wet too long causes snow mold, and without enough airflow even grass smothering, leaving bald patches next spring. But a light layer of leaves shouldn’t be cause for alarm – remember, a few leaves here and there will feed the lawn the nutrients it needs. You may consider using a leaf blower to thin them out if they are piled too high in some areas, allowing the turf to breathe through the winter. And when you think about it, if your non-native turf grass is so fragile and takes so much special care to grow well outside it’s natural environment…*maybe the problem is the grass, not the leaves?

*Our obsession with a 1950’s American Dream Lawn (which actually harkens back to medieval castle-dwelling elitism) is a problem; its a multi-billion dollar industry that relies heavily on chemical inputs, replaces native habitat, and sucks up millions of gallons of drinkable freshwater, but produces no useful food crop. Ready to ditch that old fashioned thinking and consider downsizing your traditional lawn space? More info here, here and here on alternatives.

Oh Leaf Me a Home

Leaves are home to lots of overwintering insects. We may not notice them, but these tiny friends are there, clinging to the underside of leaves and crawling into the leaf piles that collect in garden beds. While the well known and well loved Monarch butterfly migrates, most of our native insects do not! They desperately need these natural places to hid in winter, often as an egg, chrysalis, or hibernating as an adult. Many gardeners work hard to support declining insect populations all summer, only to ruin all their hard work in the fall when they take all their leaves to the curb.

Many butterflies and moths depend on leaf litter for shelter.

Paper or Plastic

Too many folks spend their beautiful fall days bagging up leaves and sending them away. This creates a lot of plastic waste. Not only are we sending enormous amounts of plastic to the landfill, all the insects, eggs, and larvae already on those leaves will die inside the bag, never to take their place in the ecosystem! The nutrients in that foliage will not return to the soil, and instead stay trapped for hundreds of years in their plastic prison.

Free those leaves, folks! Let them decay and feed the soil microbiome. If you must haul them away, load them onto a tarp for transport, or opt for paper bags that can be composted with the leaves.

Our student employee Rachel shows the size of a typical paper yard waste bag.

I love a lush, green lawn as much as the next person, but we can all aim to achieve a useable lawn space while also being kind to the environment. If you have too many leaves in one area, spread them out, move them to your garden as free mulch, or start a neighborhood leaf compost pile. If you must haul them away, stick to compostable or reusable containers and consider taking them to a city compost area or even your local Arboretum! Doing your part to help the environment, in this case, means less work for once. So stay inside and watch that football game, the leaves in the yard can wait.

Valley Center Public Library Pollinator Garden

Earlier this year, I created a native plant design for the Valley Center Public Library. After a group of volunteers helped get it planted, they have diligently weeded and watered it through the summer. Thankfully, they have an automatic sprinkler system. But they established the plants by hand watering, which was no small task.

Sumac next to small foot bridge over the drainage swale

Focal Points

Last week I took a field trip to check out the progress of their garden. It survived the summer and really filled in nicely. Some of the highlights were the Raydon’s Favorite aster, Twilight Zone little bluestem, American beautyberry, and switchgrass. The solar powered bubbling fountain and large butterfly bench donated by a local resident add a nice spot to sit and enjoy the garden.

Butterfly bench in the garden

Opportunities for Education

The garden is just north of the new library. It has walking paths and a small bridge over a wet area. It has a diverse selection of plants to create habitat for pollinators. We included several types of milkweed scattered throughout the garden, which will attract monarch butterflies. The adult monarchs laid eggs on the milkweed, which hatched into caterpillars, which then turned into adults. The garden stewards were able to share this lifecycle with the children and adults who visited the library.

Bubbling fountain perfect for supplying water to pollinators

It was a warm sunny day when I visited. There were dozens of pollinators working on the asters, which were in full bloom. The garden has been a tremendous success. The ladies who manage the site have done a wonderful job. They are connecting people of all ages, but particularly children, to the outside world and showing them different pollinators that can be attracted to a garden using native plants.

As the garden matures, the educational opportunities will become more numerous. These connections with nature are important formative experiences that will impact people for years to come. Keep up the good work!

It’s hard to see but this Aster ‘Raydon’s Favorite’ was covered with all sorts of pollinators.

Final update: Buffalograss Experiment

As the growing season comes to a close, I like to take account of the garden before it goes completely dormant. Certainly, this has been a challenging year in the garden. The plants I installed last May in front of my house are still alive, but it took daily watering through the summer to keep them going. It is safe to say that without regular attention and water, I would have lost all of those tiny plants. I am still watering them twice a week.

Aster oblongifolius ‘Raydon’s Favorite’
Amsonia hubrichtii ‘Butterscotch’

Here at the Arboretum, I find the resiliency of the prairie and certain display beds encouraging. While they are under stress, these plants adapt well to the high and lows along with wet and dry conditions. I have also been monitoring the buffalograss experiment I started over two years ago in the fall of 2020.

Our Experiment

As a reminder, in the fall of 2020, we tried a new seeding technique with buffalograss. We had our area prepared and ready for planting. That November, we seeded the area with annual ryegrass and buffalograss seed. The ryegrass is a cool season grass that prefers cooler weather. Once it germinated, it held the soil through the winter while the buffalograss seed naturally planted itself with the freezing and thawing of the soil. The round buffalograss seeds did not germinate because soil temperatures were below 60 degrees.

Area before planting, November 2020
Annual ryegrass mowed for the second time in the spring of 2021

The Next Year

In the spring of 2021, the buffalograss seed germinated as the soil temperatures warmed. By May, the new seedlings had started to spread under the canopy of the ryegrass growing from the previous fall. As the temperatures warmed into the summer, the annual ryegrass faded since it is a cool season grass and the buffalograss became more prominent. By the end of the summer, new small clumps of buffalograss established, slowly spreading but healthy.

Since Germination

We mowed the annual ryegrass weekly that first year. It is important to keep the canopy open so the sun could warm the soil allowing the buffalograss seeds to continue to germinate. Buffalograss takes two to three weeks to germinate. The seeded annual ryegrass expired on its own with warmer summer temperatures. As the ryegrass died, the roots of the ryegrass continue to hold the soil as the buffalograss spread slowly the rest of the summer.

Buffalograss clump will benefit from a pre-emergent herbicide application next spring.

UPDATE: Analysis and what I would do differently

I would deem this buffalograss experiment a success. Honestly, I thought the buffalograss would spread more over the past year, but there are many clumps sprinkled throughout the area that are getting larger. The additional costs to purchase annual ryegrass seed are offset by the time and water saved compared to the traditional seeding method.

We will be putting down a pre-emergent next spring to keep the crabgrass and other summer annuals from germinating. Some pre-emergent herbicides safe for use in buffalograss are Barricade (prodiamine), Pendulum Aquacap (pendimethalin), Dimension (dithiopyr), and Specticle (indaziflam). There are some nice clumps of buffalograss, but they are hampered by intense weed competition. Weed competition was aided by tillage (soil disturbance), and the backfill soil added along the new sidewalk, which was full of weed seeds.

I would only use this seeding method on smaller areas of less than 1000 sq/ft. In my opinion, larger areas that are properly prepared should be planted from seed in the summer before August 15th. We seeded a larger area this past summer to buffalograss using the traditional method and had good germination and coverage. Here are some other things I would do differently:

  • Reduce the seeding rate of the annual ryegrass: Though the packaging recommends 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 is better to establish annual ryegrass with slightly warmer temperatures, but not so warm that the buffalograss seed germinates.

Words of Encouragement in a Drought

We have all seen wonderful pictures of lush plants and fertile prairies in magazines, on television, on social media or other websites. These plants seem to be growing effortlessly. They have beautiful blooms with scarcely a leaf out of place. That is not the reality we are living in Kansas right now. Honestly, our gardens look a little tattered and worn down from the summer they have endured. The drought has taken its toll. 

The sun sets on another growing season.

Frankly, this time of year we might feel as tired as our garden looks.  We might even question why we do it. But don’t forget that a sustainable and resilient landscape doesn’t just happen on its own. It takes a little effort, but the rewards are worth it. Consider all the benefits of a native garden:

  • Saves water.
  • Doesn’t require fertilizer or pesticides.
  • Adapts to our climate.
  • Provides erosion control.
  • Reduces stormwater runoff.
  • Restores natural habitats.
  • Preserves biodiversity.
  • Attracts pollinators.

Fortunately, the native plants have survived. There are still some blooms on goldenrods, heath asters, blue sage, New England aster and aromatic asters in spite of the ongoing drought. The grasses, though stunted, are seeding out and have attractive autumn colors. True, it can be discouraging this time of year as you compare your garden to those idyllic gardens on paper or the web, but don’t lose heart. Your habitat garden is still functioning as it should.

Pink Muhly Grass in full bloom

Fall is the time to step back and appreciate your habitat landscape for what it is. Certainly, there might be more you could add or do, but this is enough for now. A successful native garden is more than aesthetics. You understand that all of these ecological benefits are important in creating a successful garden too. When you see that your garden is inviting to a diverse group of pollinators and wildlife, you know that you are creating something worthwhile.  

Resilient autumn landscape (Aromatic aster, little bluestem, new england aster, Missouri blackeyed susan seedheads, and false sunflower)

Plant Profile: Goldenrods (Solidago sp.)

Right now in prairies, woodlands, roadside ditches and home gardens, wonderful displays of native grasses along with wildflowers blooming yellow, white, and lavender are putting on quite a show. The yellow wildflowers are most likely either sunflowers or goldenrods. Each is quite beautiful and teeming with pollinators.

Solidago ‘Wichita Mountains’ blooming in the Compassionate Friends Garden

Goldenrods are just as diverse and variable as sunflowers. While many landscape plants have already reached their peak and the flowers have faded by September, goldenrods have become the stars of the show as they brighten up the landscape. Their golden yellow autumn inflorescences are striking.

In spite of their attractiveness, goldenrods have a reputation for causing allergies. In truth, this is unlikely, because goldenrod pollen is large and heavy and is not carried by the wind. Rather, it is giant ragweed (Ambrosia sp.) that is spreading pollen through the air at the same time.

These wildflowers are insect-pollinated by many wasps, moths, beetles, honey bees, monarch butterflies and other beneficial pollinators searching for a sip of nectar. In total, 11 specialist bees and 115 different caterpillars need these plants. There are around 50 species of insects with immature forms that feed on the stems of goldenrod. In addition, seeds and foliage provide food for some birds and mammals. Across the board, goldenrods are of huge value to wildlife and one of the keystone wildflowers for pollinators.

Gray Goldenrod-Solidago nemoralis

Goldenrods are adaptable to a wide range of conditions in nature, making them a great choice as a landscape plant. They grow naturally in soils from wet to dry. Even the drought conditions we have been experiencing have not kept these denizens of the prairie from blooming. There is a goldenrod that will grow in your garden.

For all their positive attributes, there are goldenrod species that don’t belong in a formal garden. Canada goldenrod for example is a highly aggressive species that spreads by underground rhizomes and seed, ultimately pushing out other smaller desirable plants. It will take over a garden in a couple of years. However, in a prairie setting with the deep roots of native grasses and competition from other plants, it can be mostly kept in check. That is why we recommend clump-forming goldenrods as a more reliable choice for the landscape relegating those aggressive species to the prairie or outskirts of the landscape (along a fence or in an alley) where they are free to roam and spread.

I like Solidago rigida, Solidago nemoralis, Solidago ‘Wichita Mountains’, Solidago canadensis ‘Golden Baby’, and Solidago ‘Fireworks’ for sunny areas. For shade, I choose to plant Solidago odora, Solidago ulmifolius or Solidago caesia. It is safe to say that goldenrods are powerhouse plants that deserve a place in your native garden.

Rigid Goldenrod-Solidago rigida (top) and gray goldenrod (bottom)
Solidago rugosa ‘Fireworks’

Fall Planting of Native Grasses

One of the questions we get at every fall plant sale is “can we plant these grasses now?” The answer is “yes, we encourage fall planting of native grasses”, but with some caveats.

Here are a few questions to answer before you jump into planting native grasses this fall such as:

  • Is your area ready to plant now?
  • Are you able to water it daily for the first few weeks and into the winter if needed?
  • Do you have the right location for these grasses?

I tend to err on the side of caution for late fall planting because losses can be incurred. However, you can be successful if you follow a few guidelines.

Around South Central Kansas, our first average frost is October 15. Typically, we plant native grasses as soon as possible in late August or early September to give them more time in the ground to get established. As a general rule, it is best to have native grasses in the ground three to four weeks prior to the first fall frost. This will give the plant time to get established with roots fully attached to the soil to absorb water and nutrients through winter.

Prairie Dropseed planted last fall

This attachment by the roots to the soil is so important because it keeps the grass from being heaved out of the ground. The natural freezing and thawing of the soil during the winter can be extremely strong, pushing partially established plants out of the ground and breaking roots, which results in desiccation and death of the plant. Properly establishing plants before winter will protect them from this force.

Another factor to successfully transplanting grasses in the fall is soil temperature. Typically, native grasses will continue to grow (root) with soil temperature above 60 degrees. So installing grass plugs in August through mid-September is a proven strategy, because soil temperatures remain optimum until after the first frost.

Switchgrass after one year of growth

We have had success with planting native grass in the fall. The most obvious benefit of this approach is that the grasses will break dormancy next spring fully established and ready to grow. As temperatures warm they will have a head start over early spring plantings.

Note: It is always good practice to check the soil around fall planted perennials (including grasses), trees and shrubs during the winter for moisture. If the top one to two inches of soil is dry, it is good to give them a light watering. Remember, they are dormant so they don’t need much.

Warm Season Grasses for fall planting:

  • Big Bluestem Andropogon gerardii and cultivars
  • Sideoats Grama Bouteloua curtipendula
  • Blue Grama Bouteloua gracilis
  • River oats Chasmanthium latifolium
  • Pink Muhly Grass Muhlenbergia reverchonii
  • Mexican Feather Grass Nassella tenuissima
  • Switchgrass Panicum virgatum and cultivars
  • Little Bluestem Schizachyrium scoparium and cultivars
  • Indiangrass Sorghastrum nutans
  • Prairie dropseed Sporobolus heterolepis

Cool Season Sedges and Grasses for fall planting:

  • Appalachian Sedge Carex appalachica
  • Bicknell’s Sedge Carex bicknelli
  • Pennsylvania Sedge Carex pensylvanica
  • Rosy Sedge Carex rosea
  • Texas Sedge Carex texensis
  • Bottlebrush grass Elymus hystrix
Mexican Feather grass planted in the fall of 2020

Disturbance

While walking on the island recently, I saw a change in the vegetation this year. During the renovation we brought in new soil, drove around, made new ruts, and stirred up the seed bank below. This disturbance altered the landscape enormously, and it will take years to transform back to what it was, if ever.

Annuals

Partridge pea, not usually found on the island, is colonizing happily there after our renovation.

The first thing I noticed is how many more annual plant species there are on the island. Some are weeds – like velvet leaf, Abutilon therophrasti – and some are native species, though they may be unwelcome spreaders, like annual sunflower. These either arrived with the new soil, or were churned up to the surface while driving with heavy equipment. When annuals appear suddenly in a bare patch of an otherwise mature and established prairie, with a little help they will disappear just as quickly. We cut the seed heads off to stop them from returning next year, and soon they will be outcompeted by the perennials and grasses.

But I do hope some annuals stick around! Partridge pea, a favorite of mine and host to Sulphur butterflies, has appeared on the island once again, and I’d like to see more of it seed out. This plant loves tough, disturbed areas, so it is no surprise it showed up here.

New Animal Activity

Pointed stump left by a beaver on our island

We have noticed our aspen trees falling one by one, and see the sharp points of their chiseled trunks. We have a beaver on our island! While we have never caught sight of it, it is obviously enjoying our grounds immensely. With the aspens mostly gone from the center of the island, the views have changed. Visibility is better to the east and it is sunnier in the sitting area.

Beavers are shapers of entire ecosystems, and they are integral to rivers and streams. And while I love the idea of having a beaver around, our pond is in fact not a natural water way, and too many of our memorial trees are at risk from our industrious friend. But he sure has caused his share of disturbance around here! The shrubs growing beneath the aspens appreciate the increased sunlight, I am sure. We successfully lived-trapped one of the two beavers, and relocated it to a new pond with the permission of the property owner.

It was no easy task, but we relocated this beaver to a stream that needs its services more than our own.

Who Are You?

There have even been a few perennials popping up that are new to me. These might have been in the soil for years, but sprouting only when given open soil and right conditions. One of these is narrow leaf golden aster. A lovely little plant making its debut right along the edge of the gravel path. There is also a large, very conspicuous patch of Rudbeckia subtomentosa that I didn’t know we had on the grounds. Just when I think I have seen every inch of our grounds, it is nice to be surprised by these new flower faces!

Rudbeckia subtomentosa, also known as sweet henry or sweet coneflower. Several large clumps are just finished blooming on the edges of the island.
Heterotheca stenophylla, narrow leaf golden aster, growing happily on the rocky edges of the island path.

Please DO Disturb

Prairies, even tiny ones on the island or in our residential gardens, are meant to change. Nothing is static in nature, and when we humans want it all to stay orderly, predictable and exactly the same year after year, we are playing a losing game. It’s much better to embrace the changes in our gardens and landscapes, and even encourage them.

Some perennials will live fifty years, while others may only live five. Everything has its expected lifespan, so when those bare spots appear in your garden, consider throwing out some native annual seed like Coreopsis tinctoria or partridge pea. These will fill the gap, provide lovely blooms, then fade away once your other plants cover the soil. After all, prairie landscapes evolved to be disturbed, either by fire, flood, or the thundering of bison hooves. Each of these creates open soil for new plants to grow and compete with the existing grasses and forbs.

Are you looking to create a dynamic, ever-changing prairie habitat of your own? Visit FloraKansas Native Plant Days next week and ask staff what native plants will work best in your landscape.

Plant Profile: Kentucky Coffeetree (Gymnocladus dioicus)

When one thinks of the Great Plains, trees are often the last thing to cross one’s mind. Surprisingly this region is home to a number of species that have found their way into yards and parks throughout the United States. The honey locust, American elm, black walnut and silver maple are as common in front yards as they are along streams and patches of woodlands of the plains. One of the more beautiful native trees found in this region is the Kentucky coffeetree, a member of the legume family. Kentucky coffeetree can be found along the eastern portion of Kansas. The tree derives it name from a common practice among early Kentucky homesteaders of grinding the seeds to make a coffee-like drink.

Mature Kentucky Coffeetree (Wikipedia)

Though somewhat uncommon in landscape plantings, the coffeetree offers many ornamental attributes. A large tree, it can reach 60 feet in height with a 30 foot spread. As of March 2022, the Kansas Forest Service state champion Kentucky coffeetree, located at Fort Leavenworth, currently stands at 100 feet tall. As the tree matures, the bark forms scaly ridges with curled edges. In winter the ascending branches present a picturesque silhouette against the winter sky. Written descriptions have labeled the tree “clumsy” looking after the leaves drop. While young trees can appear awkward their first few years, mature specimens develop stout trunks and main branches, reminding one of their innate toughness and durability.

In spring the tree may be slow to leaf out, but the patient observer is soon rewarded with bipinnately compound, bright green leaves with dainty, ovate leaflets that give the tree a soft, fine textured appearance throughout the growing season.

The bipinnately compound leaflets

Kentucky coffeetrees are individual male and female trees. The botanical term for plants with male and female flowers on separate individuals is dioecious, a condition also found in Ginkgo, juniper, and Osage orange. Flowers appear in May and June as graceful racemes. The male flowers are somewhat inconspicuous and green-yellow, while the female flowers are somewhat larger and pale yellow-white. Both types of flowers are quite fragrant. Each of these flowers are favorites of pollinating insects.

Creamy white flowers in the spring (Wikipedia)

Fall color is often a subdued yellow and female plants will often produce a reddish brown pod filled with incredibly hard, round, slightly flattened seeds. The hard coats allow seeds to lay dormant in the ground for long periods of time until weathering and soil bacteria wear down the tough shell, allowing germination to occur if temperature and moisture are adequate. Professional growers often soak the seed in concentrated sulfuric acid to thin the coat enough for water and gas exchange (a dangerous practice for the average home gardener). Another option is to use fine sand paper to sand down the shells so several seeds will potentially sprout. Don’t sand too much.

Bean-like pods and seeds of Kentucky coffeetree

Due to the coffeetree’s large size and the sometimes “messy” pods from the female trees, it is often not the best selection for the average yard. However, it is well-suited to large open areas, along streams and in park settings. It is not particular about soil, but best growth occurs in deep moist ground. Drought tolerant, it experiences very few problems.

In the wild, small colonies of coffeetree can be found when new trees form from the root suckers. This is usually not a problem in the landscape if the tree is mulched and regular mowing occurs around the tree. Transplanting in most successful with small plants, because the tree develops a course fibrous root system that limits the transplanting success of larger trees.

In the Arboretum’s bird watch area, a small coffeetree is planted just below the big bridge.

I like good coffee. Lucky for us that our coffee supplies for drinking are more than adequate, but one should still consider this beautiful, tough native tree for your landscape.

Great Plains Skink

Great Plains Skink (adult form) from my urban garden in Newton, KS (May 28, 2009)

Increasingly, I find enjoyment in the wildlife attracted to my native plant gardens. One species I’ve especially loved seeing has been the Great Plains Skink (Plestiodon obsoletus). For at least 13 years (since I took the above photo), I have observed this species coming and going from under my garage or deck, around the foundation of my house, and to and from my native plant gardens. The combination of these habitats appears to provide suitable cover, food, and thermoregulation for this ectothermic (cold-blooded) reptile.

Identification

The adult Great Plains Skink averages 7-9 inches in length (as large as 13″) and is the largest, most common, and most widespread (nearly throughout the entire state) of the seven skink species in Kansas.

Great Plains Skink range map from the Kansas Herpetofaunal Atlas

Coloring ranges from tan with dark brown markings to light gray or olive. The following photos show some of the variations in colors and markings for this species from juvenile to adult.

Natural History

In addition to my urban gardens, it is referenced in the book Amphibians, Reptiles, and Turtles in Kansas (Collins, Collins, and Taggart, 2010) that the Great Plains Skink commonly inhabits open, rocky hillsides with low prairie vegetation. Their diet consists of spiders and a variety of insects such as grasshoppers, crickets and beetles.

Breeding occurs in May after which pregnant females dig deep burrows under rocks and lay 5-32 (average of 12) eggs. After a 1-2 month incubation period, hatched young skinks may take several years to reach sexual maturity.

Diversity in the Home Landscape

Landscaping with native plants leads to attraction of a variety of wildlife species. This bigger picture food chain or ecosystem connection between plants and the animals they support has become one of the most interesting and satisfying incentives of incorporating as much native plant diversity into my home landscape as possible. Whether these plant-animal or predator-prey interactions attract butterflies, monarchs or birds that eat them, birds in general, large beetles, fireflies, cicada killers, preying mantids, bats, or skinks, I’m intrigued with observing every single connection and the underlying story it tells.

I’ll leave you with the following observation…from just last night. We added a red fox to the list of species that has visited our urban home landscape. It spent about an hour in a tussle with a flexible plastic downspout tube in one of our gardens. This particular shade garden is where I have most recently seen a skink in recent weeks. Was “skink-in-a-tube” the cause for this entertainment? Will I see the skink again in this area? Whatever the case, I will enjoy continued observations and looking for answers.

Is there still a skink somewhere in this photo?

Flower Form and Function

Who doesn’t love a perfectly round peony or a deep red rose? While humans are mostly concerned with the aesthetic qualities of flowers, that’s only half the story. The shape, size and color of a flower are less about fashion and more about function, changing over millions of years to be recognized and pollinated by certain methods. Understanding a bit about flower form can help you shop smart when you are trying to create pollinator friendly landscaping.

File:Longitudinal section of raspberry flower.gif
Flowers are complicated and variable structures. Knowing a bit about them ensures you are planting flowers that actually fit with our native pollinators. Public domain image from Wikimedia Commons.

Coevolution

Coevolution is the concept that living things in close proximity to each other affect the characteristics they develop over time. For instance, the length of moth and bee tongues and the length of some tube-shaped flowers in their geographic area are closely related; as one grows or shrinks over thousands of years, so does the other since their positive interactions impact what traits are passed to the next generation. Our prairie plants in the midwest are no different. Liatris, compass plants, sunflowers and grasses all have complex, dependent relationships with native insects and animals. Flowering plants are still changing today, sometimes naturally and other times with a little push by humans.

Keeping Your Form

Flower form often determines its function in the environment. Each different flower shape is related to its pollinator mechanism. As mentioned above, tube flowers are a favorite of hummingbirds and long-tongued insects because their mouth physiology matches the shape. With hundreds of variations in shape and arrangement, you can spend years studying them all! As new horticultural varieties of native plants are introduced into the garden center, it is important to know what the original form and function of the flower was to be sure it is still serving that purpose even after hybridization.

Breeders hope to make more native plants commercially accessible to the public and to create reliable performers in the garden. But sometimes the changes they make (either through seedling selection or via hybridization) can be detrimental to flower form or leaf palatability, which decreases its usefulness in the ecosystem.

There are many patented varieties of Eupatorium dubium that focus on curtailing the height of the plant, which at a gangly six feet is unsuitable for most garden spaces. Anecdotally, we have found that pollinators flock just as much to the dwarf varieties like “Little Joe” as to the wild type, since the flower shape and color has not changed significantly between the types.

Hybridization

In plants, natural hybridization leads to new characteristics and creates genetic diversity. Humans can hybridize plants by transferring pollen from a plant of interest (say, an especially delicious tomato) with another plant of interest (perhaps a tomato with exceptional vigor). The seeds produced from that cross would be a new, genetically unique plant that hopefully has both of the aforementioned traits. This is not new, and has been happening since Gregor Mendel’s time!

Man-made crosses can lead to higher yields or increased drought tolerance, but they also have their downsides. Cultivars (cultivated varieties) can solve many tricky garden problems but sometimes have decreased ecosystem functionality. Try to shop for plants closely resembling their parent plant in the important categories: flower shape, color, and leaf color. Early research suggests that selections with increased drought tolerance, plant height, and other factors aren’t as influential to pollinators as the flower and leaf changes.

‘Julia’ is a hybrid coneflower sporting orange flowers on strong stems. While we all love these colorful Echinacea varieties, and pollinators seem to as well, they are not nearly as long lived as the less vibrant native species. We don’t know yet how the color change affects the foraging behavior of our native insects, so more research is needed. Photo courtesy of Walter’s Gardens.

How to keep it all straight?

You don’t have to be a botany expert to make good choices. When buying some of the commercially available cultivars/varieties/hybrids, simply try to choose ones closest to their wild parent in appearance. If the flowers are doubled, or a wildly different color than is naturally occurring, that should be a red flag. We can all keep educating ourselves about the pros and cons of cultivars while still enjoying manageable and well-planned native gardens. Planting native trees, shrubs and perennials in your landscape increases the genetic diversity and ecosystem function of your neighborhood. It is worth the extra work, and learning along the way will make the native garden experience even more rewarding!