Learning About Leaves

Every year I learn more and more about how important leaves are for the ecosystem. We have several blogs about leaves already, (including Scott’s best management practices and my sustainable leaf-raking tips) but this information often needs updating and augmenting. The more we know, the better we can do! And that applies to us too here at Dyck Arboretum. Here are some new ideas I am implementing around the grounds to a-leave-iate our leaf problems.

My dog Rosie loves leaves, and so do I! Raking (and playing in) leaf piles was a staple activity of my childhood that I still enjoy with my family today.

Leave them when you can…

I know it is not always possible, but the easiest and best practice is leave leaves were they fall. Here at the Arboretum we let leaves freely accumulate in hedgerows, shrub borders, and garden beds, even though it might not look traditionally ‘tidy’. Many insects use leaf litter for shelter and breeding, and insects are the linchpin to our ecosystem! As E.O. Wilson said, they are the little things that run the world. Their populations are in serious decline across many species, especially the leaf-loving firefly.

Allowing leaf litter to stay undisturbed through fall and winter is an easy way to improve insect habitat. While you might be worried about all those ‘bugs’ snoozing in your landscape, don’t be. Just remember to keep the leaf layer only a few inches thick and not piled high directly up against the foundations of your home.

Fall colors on the west side of the Arboretum. Stunning, but short lived! Soon these leaves will be swirling around the sidewalks and piling up on paths.

Don’t Shred

A light sprinkling of leaves will not harm your lawn, but they can cause damage when too thick, matted, and wet over the winter, so you may have to remove them. Many folks rush to the mower and shredder for this task. We have a large mulching mower that I once happily raced across all the Arboretum lawns with.

BUT – I’ve learned now that many insects have already laid eggs or cozied up for dormancy in these leaves. So shredding likely kills all those beautiful and beneficial insects we are hoping to attract. I am attempting a 60/40 rule this year: remove the bulk of the leaves by raking, shoveling, or blowing, and only mow that last forty percent in particularly important/sensitive lawn area. For an acreage this large it is impractical to do much by hand, but I am hoping my small effort will make a positive difference for the insects that call the Arboretum home.

Thanks to volunteers we are able to rake and redistribute some leaves. Without their help, much more would have to be shred with a mower to save time.

Redistribute

After the wonderful workout of raking leaves, it is time to put them…where? If you have a compost pile, that’s a great start. Or layer them over your vegetable garden. Pile them under cedar trees or in weedy spots you want to smother.

Dyck Arboretum is not accepting community leaf donations this year as our leaf house is deconstructed at the moment, but many cities (including Hesston) have a free drop off leaf compost area for their citizens. For extra sustainability, skip the plastic bags and move your leaves loose with just a tarp and a truck bed. If you must use bags, don’t tie them up so they can be easily dumped and reused next year when the leaves fall again.

Our parking lots accumulate leaves quickly, and they begin to compost as they pile up in the curb. We use a grain shovel to scoop them out, rake them up, and toss them around the trees and shrubs as good mulch and fertilizer.

This time of year I see piles and piles of bagged leaves on the curbs of our neighborhoods and cities. We can certainly do better now that we know what a gold mine of habitat and nutrients these leaves really are. So get out there and jump in those leaves, spend a day in the fall sunshine, and do your part to help those “little things” keep running the world!

Plants for hillsides and slopes

One of the more common landscaping conundrums is deciding what to plant on steep slopes or hillsides. These areas require plants that can establish quickly, have fibrous root systems, that hold soil to control erosion, are tolerant of fluctuating soil moisture and potentially poor nutrient availability, and require little care once established.

Slopes and hillsides are already challenging because of sun exposure, and the degree of the slope only exacerbates the problem. Establishing plants from seed is the most economical choice, but is also the most subject to erosion for the first 3 to 5 years until plants get established. Often, turf grass such as fescue, buffalograss, or bermuda grass is the first groundcover choice for keeping soil in place, but mowing these sloped areas can be a challenge, maybe even dangerous. Turf does not create much habitat for wildlife and pollinators either.

There are many plants that will establish cover more quickly than seed. These native plants offer a lower maintenance alternative to a mowed lawn. The following list is just a start. Remember to plant more densely (1-2 feet apart) so the area gets completely covered with plants quickly.

Grasses

The following grasses, with their extensive fibrous root systems are ideal plants to stabilize a steep area and prevent soil erosion.

  • Andropogon geradii (Big Bluestem)
  • Bouteloua curtipendula (sideoats grama)
  • Chasmanthium latifolium (River oats)-Can grow in sun or shade but is aggressive. It will spread by seed and rhizomes to crowd out most other plants.
  • Elymus canadensis (Canada wildrye)
  • Panicum virgatum (Switchgrass)
  • Schizachyrium scoparium (little bluestem)
  • Sporobolus heterolepis (prairie dropseed)
Little Bluestem with Aromatic Aster and New England Aster

Wildflowers

  • Achillea millifolium Yarrow
  • Allium cernuum Nodding onion
  • Amsonia sp. Blue star
  • Aquilegia canadensis Columbine
  • Asclepias tuberosa Butterfly weed
  • Baptisia australis False blue indigo
  • Dalea purpurea Purple Prairie Clover
  • Echinacea purpurea Purple coneflower
  • Eutrochium (Eupatorium) maculatus Joe-pye weed
  • Filipendula rubra Queen-of-the-prairie
  • Liatris pycnostachya Prairie blazing star
  • Liatris spicata Dense blazing star
  • Rudbeckia sp. Black-eyed Susan
  • Penstemon digitalis Penstemon
  • Symphyotrichum oblongifolium Aromatic aster
  • Solidago sp. goldenrod
  • Tradescantia ohiensis Spiderwort
  • Veronicastrum virginicum Culver’s root
Amsonia ‘Butterscotch’ and Aster ‘Raydon’s Favorite’ with mulch between plants to control erosion.

Trees and Shrubs

  • Amelanchier canadensis Serviceberry
  • Cercis canadensis Redbud
  • Coruns sp. Dogwood
  • Crataegus viridis Hawthorn
  • Heptacodium miconioides Seven Son Flower
  • Ilex verticillata Winterberry holly
  • Lonicera reticulata Grape honeysuckle
  • Prunus Americana Wild Plum
  • Prunus sp. Sand cherry
  • Prunus virginiana Chokecherry
  • Rhus aromatica Fragrant sumac
  • Sambucus canadensis Elderberry
  • Viburnum prunifolium Blackhaw Viburnum

If the erosion is already very serious, you might want to consider using erosion-control blankets to stabilize the erosion area until the plants can take over the job. The erosion-control fabric works by slowing the runoff water and allowing sediments to fall out rather than be washed away. Choose a mat that will decompose over time, e.g. straw or jute, rather than something made of plastic. Start by slicing a small opening in the mat so plants can be put into the soil beneath. I recommend hand watering during establishment as much as possible since sprinkler irrigation can increase soil erosion.

For more gentle slopes, heavy mulch or pea gravel can be used to control erosion during establishment. Each slope situation is unique, but if you can, the best strategy for stabilizing a slope with plants is to establish vegetation at multiple levels—plant trees, shrubs, grasses and wildflowers. A multi-level canopy will do the best job of intercepting and slowing precipitation before it hits the ground, reducing surface erosion. Different vegetation types also provide both deep and spreading roots that stabilize the entire soil profile. Generally, it takes 2-4 years to get these plants fully established and roots anchored into the slope.

Slopes covered with a variety of grasses including switchgrass and fountain grass at Wichita Art Museum. Photo by Brad Guhr

Summer Garden Checklist

Kansas summers can discourage even the hardiest gardeners. However, taking time to manage your garden now will help your garden later. Here’s my Summer Garden Checklist for the Kansas gardener.

Control Warm Season Weeds

Summer brings with it a new set of weeds to control. Hot weather germinates summer annuals like crabgrass, foxtail. Nutsedge and other weeds invade your lawn and landscape as well. Manage weeds using nonchemical methods such as cultivation, hand weeding, or mowing; use toxic chemicals as a last resort. 

Mowing regularly and occasionally edging along sidewalks and walkways is needed to ensure your lawn is not overrun with weeds. In a landscaped bed, hand pull any of these weeds, especially if they have seed heads.  It is so important to not let these weeds go to seed. Stay vigilant even though the summer heat tries to squash your enthusiasm. A little extra effort now will make your garden better this fall and into next year. 

Crabgrass in tree mulch ring controlled with roundup: one treatment should clean up the mulched area and keep it weed free the rest of the season.

Be Water Wise

To reduce evaporation, water when temperatures are cooler and air is still, usually in the early morning. Water deeply to moisten the root zone, but infrequently. About an inch of water each week is a good rule of thumb!  If you have invested in container plants, they will need daily watering, as soil in pots can dry out quickly and damage plant roots on hot summer days.  Each of our gardens have indicator plants that show stress first, let these plants be your guide as when to water.  For new planting started this spring, water when the top one to two inches of soil is dry.  Remember it takes three to five years for sustaining roots systems to develop for most native plants.  Supplemental watering is necessary to encourage growth and root development in these young plants. 

We use pressure compensating 1/2 inch soaker hoses to efficiently water trees, shrubs and a few flower beds. Each emitter puts out 1 gallon of water per hour.

Prepare for seeding

If you are wanting to establish native prairie plants from seed, now is a great time to prepare your area.  Mow your area short (1-2 inches). Control perennial weeds such as bindweed or Bermuda grass by carefully spraying the area with Roundup. It will take several applications to get these problematic weeds under control. If you can see soil, tillage is not necessary. If you can’t see soil, till lightly to expose some bare soil. Remember, each time you till, you bring up more weed seeds, so tread lightly. 

Measure your area and order a seed mixture that matches your site. A good seed mix ratio of wildflower to grass is 70% wildflowers to 30% grasses. Grasses tend to dominate over time, so this ratio will give the wildflowers a good start. We typically spread seed in November and December after the soil temperature has dropped enough to discourage germination. The natural freeze/thaw of the ground will work the seeds down into the soil to the proper depth for germination next spring. 

This is the seed mix we established along our newly renovated path.
Sidewalk edge planting: We mixed some sand with the seed mix to make it easier to distribute. We then let the natural freeze/thaw of the soil plant the seed for us through the winter. Germination occurred the following spring when soil temperatures rose above 60 degrees.

Trim

Now is a great time to trim back perennials that have become unruly. Perennial and grasses that are encroaching sidewalks, paths, and structures can be sheared back to size. If this is a problem every year, you may consider moving the taller plants to another spot. Plants can be divided next February or March before they start to actively grow. 

Low hanging branches from trees can also be pruned. It is getting late in the season to do much pruning on shrubs. New growth may not have enough time to get hardened off before cooler/colder weather.  If a branch or shoot is in the way, then prune it, but prune sooner rather than later. If you can wait until the shrub goes dormant this fall, then wait. 

As a general rule, early spring flowering shrubs such as forsythia, lilac and spirea should be pruned right after they are done blooming since they bloom on the previous year’s growth. Pruning right after blooming will allow the shrub to grow and develop a new set of buds for the next spring. 

A large compass plant that needs to be trimmed away from the path.

Finally, remember “WHY” you are gardening; creating habitat, conserving water, aesthetics, attracting pollinators, attracting birds and other wildlife or curb appeal. Let your “WHY” reinvigorate you to take care of a few extra tasks that will give your landscape a boost. Don’t sweat the small stuff and don’t forget to step back to enjoy what you are trying to create. If it is all work and no enjoyment, then what is the point.

Pale purple coneflower with a common buckeye butterfly. Fun to watch!

Do You Have Nutsedge?

This time of year, yellow nutsedge (Cyperus esculentus) and purple nutsedge (Cyperus rotundus) become problematic in the landscape. These problem weeds have triangular grass-like leaves and form colonies if left unchecked. It is not a grass, but rather a sedge. The key identifying feature is the triangular stem in cross section, as opposed to a round cross section in grasses. 

In Lawns

Nutsedge is a common weed in lawns with waterlogged soil, and its presence often indicates that drainage is poor, irrigation is too frequent, or sprinklers are leaky. Once established, however, it will tolerate normal irrigation conditions or drought.  Established nutsedge plants grow faster than many lawn grasses, so it is often noticed when it outgrows the surrounding grass. The leaves are bright green and have a waxy appearance in summer when surrounding lawn grass may be a lighter green.

Management in Lawns

As with most weeds in lawns, the best defense is to maintain a healthy, dense turf that can compete and prevent weed establishment.  Water lawns on an as-needed basis, not on a regular schedule. Overwatering increases disease and provides a better environment for nutsedge to grow. 

For larger infestations in lawns, spot spray with a liquid, selective herbicide that contains the active ingredient: Common Name: Halosulfuron; Trade Name: Manage, or Sedgehammer and others or Common Name: Sulfentrazone.  Mixing these herbicides with a non-ionic surfactant that breaks down the waxy leaf coating to the chemical is more effective. 

In Mulch

Nutsedges thrive in areas with little or no competition.  In mulch rings around trees and between flowers offer ideal conditions for large colonies to form. Actively growing stands of nutsedge have extensive root systems that can reach as deep as four feet. Nutsedges produce underground tubers and runners that make it difficult to pull out of the ground. Each of these can produce another plant if not completely removed.

Mechanical management

Digging out or using an appropriate weeding tool to remove the underground ‘nutlets’ is the primary means of mechanical control of nutsedge. This is a viable option at the beginning of an infestation and on young weeds.  If you want to avoid spraying chemicals for control of nutsedge, you need to relentlessly pull the plants every time a new plant emerges.  It is most active in May through October.  We have also smothered nutsedge with cardboard and two to four inches of mulch. Nutsedge may emerge again next year after the cardboard has decomposed.

 

Spraying

We have had success spraying nutsedge.  We use Manage™ (Sledgehammer) herbicide. It is a selective herbicide that only kills nutsedge and can be sprayed in close proximity to other perennials, shrubs and trees. It takes a few weeks for the plants to show decline, but Manage™ kills the whole plant including the runners and tubers. I have used Roundup as a control, but it is a non-selective contact herbicide that kills the weeds it contacts.   

Nutsedges are often unwelcome competition for our more desirable plants. These “weeds” can be controlled by a healthy, actively growing landscape. Competition and vigorous plantings will push these plants aside. If you do find it in your landscape, remove it immediately. If you have larger areas, be persistent, over time, you will get the upper hand.  Be as unrelenting as the weeds.  As they say on the Red Green Show, “We are all in this together. I am pulling for you.”

All About Bindweed

It’s a plant all gardeners know well: the infamous bindweed. Thought to have been accidentally introduced from Europe by crop seed contamination in the 1700s, it has established itself all over the North American continent. But I recently found a native relative to this terrible pest, and upon further research, learned some fascinating facts about this plant family! The more we know, the more effective we can be at eradicating the invasive ones and properly identifying our look-a-like native species.

Common field bindweed is often pink, white, or even striped. Photo from wikimedia

Common Bindweed, Uncommon Problem

Convolvulus arvensis is the bindweed we all know and hate. It is a member of the morning glory family (Convolvulaceae). Its funnel shaped flowers hint at its lineage, and they are often visited by sweat bees and other small pollinators. Blooms may be white, pink, or even striped. Even farther up it’s family tree we find it is related to nightshades (think: tomatoes, peppers, potatoes, horsenettle) all a part of the order Solanales. Bindweed has spread all around the world and is listed as one of the United States most problematic agricultural weeds. It causes millions of dollars in crop losses every year.

Good Bindweed and Bad Bindweed

I didn’t know there was such a thing, but good bindweed exists. There are native species, often called false bindweeds, that look very similar but do not grow as aggressively. I was walking along the pond edge here at the Arboretum when I spotted what I thought was a bindweed. Odd, since bindweed rarely colonizes densely planted areas, especially in the shade. When I came closer I saw just how big the flower was. It was easily double the size of a regular bindweed flower, and a much brighter white.

This plant was actually a Calystegia species, likely low false bindweed (C. spithamaea). To my knowledge, this is the first occurrence of this species on our grounds. It could have come in with some flood waters, or sprouted after the disturbance of our island renovation efforts. We may never know, but we can surely enjoy its blooms and try to preserve it.

C. spithamaea isn’t usually found in our state, but it isn’t impossible. The native range is much farther east and north, but it could have found its way here in a seed mix ordered from out of state. There are other Calystegia’s that are more commonly found in our area, but they don’t match it’s growth habit as well. Oh the fun of solving plant ID mysteries!
Calystegia spithamaea has a pure white flower and is much less vigorous and vining than field bindweed.
The flowers are much larger than those of common field bindweed.

Best Management Practices

If you have the non-native kind of bindweed, you are probably in a daily struggle to keep it under control. Common bindweed is a perennial, meaning its roots survive the winter. Simply mowing it or cutting off the flowers will not successfully eradicate it from your lawn and garden. Also, those roots are incredibly tough and can be 20 feet deep! Pulling it is an exercise in patience, as it seems to regrow before your eyes. Most bindweed can easily resprout from small pieces of root left behind in the soil. If you have a small patch and you weed often, you may be able to get ahead of it and eventually weaken the root system. For folks who have A LOT of bindweed, here are some of the most effective controls:

  • Solarization (clear plastic placed over the area for a full growing season)
  • Smothering (cardboard with a thick layer of mulch on top for at least a full year but more likely 2 to 3)
  • Chemical control (glyphosate, 2-4D, paraquat, etc.)

And remember, avoid tilling the soil! Freshly disturbed soil is easily colonized by bindweed, and often there are seeds in the soil that get churned up to the surface, ready to germinate. Leave the soil undisturbed and only dig/loosen it in the specific holes where you will be planting.

Preparing to Establish a Landscape with Native Plants

It’s obvious to me that interest in landscaping with native plants continues to expand.  More and more people are reconnecting with the natural world through their native landscapes.  Besides creating habitat for wildlife, including pollinators and insects, these newly developed gardens conserve water, reduce chemical and pesticide use and beautify the landscape.  As you think about preparing to establish a landscape with native plants, here are some things to consider.

Analyze the Location

You know your garden better than anyone. You know the soil type. Does it stay wet or is it extremely dry or something in between? You know how much sun your area receives during the day and throughout the year. You know where the water flows. Are there areas that you can utilize as a background or backdrop?  Is there something you are trying to screen? Is there an area you are trying to develop? These are important questions that ultimately determine the types of plants you will choose.

Prepare the Site

Site preparation doesn’t have much to do with plant selection, but it is an important step to consider any time you are preparing to establish a landscape. You need to get perennial weeds such as bindweed and Bermuda grass eradicated before you plant your garden. If these weeds are not eliminated, they will overrun and out compete anything you plant. Trust me on this. I am still fighting these weeds in certain areas in my yard because I didn’t complete this step.

It is also good to define the area with some kind of border. Start by laying out a garden hose and moving it around until you settle on size and shape that seems appropriate for the space. I recommend starting small. Develop an area you can manage and fits your lifestyle. You can always expand, but a bed that is too large can quickly become overwhelming. Once you have defined the border, I use metal edging, brick, limestone or landscape stone as a buffer for a mower or weed eater. Edging makes your native garden look intentional.

Choose the Plants

Once you have gathered all this information about your site and all the initial work has been done, you are ready to decide which plants will grow well together. The most important step in the selection process is matching plants to the site. There are a group of plants or a plant palette that will grow in your site with little or no water once fully established. You need to become familiar with every aspect of the plants through investigation, research and experience. I often start with one or two plants I know will grow in this location. Once I have established them as the foundation, the other plant combinations come easier.

I design each landscape with the finished picture in mind. I consider heights, bloom time, habit, forms and textures. We often only think about these plants when they are in bloom. But don’t forget their other qualities, such as seed heads that provide visual interest in the winter months. It provides you an opportunity to highlight these qualities with another perennials or native grasses (e.g. coneflower seed heads against little bluestem). 

I group plants together for visual affect and stagger blooms throughout the season. Conceptually, I lay out plants in such a way that plants with different bloom times are next to one another. For instance, I would not plant two spring bloomers next to one another, but rather a spring bloomer next to a fall bloomer next to a summer bloomer. I even like to mix some grasses with certain perennials so you have the structure of the grasses propping up the perennial. Also, you want something coming into bloom and going out of bloom from spring through fall. Grasses add wonderful texture and movement to the garden during the winter months.

Maintenance

One of the misconceptions about native plants is that you just plant it and forget it. That is generally not the case. Establishing native plants in your garden or landscape usually requires putting extra work in those first few years. It takes time for those root systems to fully develop. Over time, you will begin to reap the benefits of native plants, especially if you have done your homework before you put the first plant in the ground.

Those tiny plants are most vulnerable during the first two or three weeks after planting. You must water them daily and sometimes twice a day in warm, dry seasons until you start to see some new growth. There is a fine line between over watering and under watering. Generally, you try to rehydrate the potting soil of those plants each time you water. Many maintenance practices used for traditional cultivated plants also work for native plants.

The first couple of years, I try to keep the tags around the plants so I don’t accidentally pull a small wildflower or grass. Pull all the winter and summer annual weeds when they are small and certainly don’t let them go to seed. February or March is the time to prepare your bed for spring. 

Northwind Switchgrass cut back and ready for spring

Your native landscape connects you to the land. The economical, ecological and beautiful garden you create can be enjoyed for years to come. I predict that your native landscape will be a hub of pollinator and butterfly activity. It will be an important link to other gardens in your neighborhood. It may even inspire you to establish other prairie gardens in your landscape. 

Your success may influence others to follow your example. A native plant garden should be cherished, because you are helping the natural world in so many far-reaching ways. Believe it or not, your garden will have a positive impact. So get started! Let your imagination and creativity inspire your design.

Bearer of the Ammonite by Paul Friesen. Photo Courtesy of Jen LeFevre

Photo Credit

Keystone Natives for the Food Web

I have been reminded over the past few weeks about about the importance of keystone natives. There is a growing body of research that touts the benefits of keystone species of trees, shrubs, wildflowers and grasses to the food web. According to Doug Tallamy, landscapes without keystone plants will support 70–75% fewer caterpillar species than a landscape with keystone plants, even though it may contain 95% of the native plant genera in the area. Keystone plants must be included in your native garden design.

Take a look at Doug Tallamy’s book, Nature’s Best Hope: A New Approach to Conservation that Starts in Your Yard for more data.

The food web includes, plants, insects, pollinators, birds, lizards, toads, frogs, and mammals, from rodents up through bears.  Each is reliant on the other for their survival. Tallamy focuses much attention on trees that support the food web such as oaks, cherry, cottonwood, willow, and birch.  However, there are many native perennials that are also key components of this food web. To provide a solid foundation for a healthy food web in your garden, start with this list of native wildflowers to include in your landscape:

Goldenrods (Solidago sp.)

These summer blooming wildflowers with bright yellow flowers can be striking in the landscape. However, they 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 that is spreading pollen through the air at the same time. The plant is 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.

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 with red switchgrass

Asters

A diverse genus that supports 112 species of insects, asters are a valuable late-season (September – November) source of pollen for bees and nectar for bees and butterflies. During the summer, the asters are host plants to the caterpillars of some of the crescent and checkerspot butterflies. As summer wanes, asters start blooming with colors of white, purple, and pink depending on the species.  Fall provides a unique challenge for pollinators and asters help with both migration and overwintering butterflies and bees. 

A few of my recommended forms are Aster oblongifolius ‘Raydon’s Favorite’ and ‘October Skies’, Aster novae-angliae varieties, Aster laevis and Aster ericoides ‘Snow Flurry’ for sun.  In a shady area, try Aster divaricatus ‘Eastern Star’, Aster cordifolius, and Aster macrophyllus.

Aster ‘Raydon’s Favorite’

Sunflowers (Helianthus sp.)

There are eleven species of sunflower recorded in Kansas. These wildflowers are not usually fit for a formal garden setting, because they spread vigorously by seeding and rhizomes.  They have a tendency to push out other desirable plants.  However, they support 73 species of insects, so we maybe need to find a place for them. 

I’m not referring to the large-headed annual cultivars you see growing in a field, but rather the true native perennials with bright yellow flowers seen growing along the roadside in the late summer and early fall.  Plants provide lots of nectar and pollen, and the seeds are eaten by many birds and other wildlife. I would encourage you to try a few sunflowers in the peripheral areas of your yard where they can spread out and have room to roam. 

Maximillian Sunflower and Big Bluestem

Milkweeds

Monarchs are in peril. Milkweeds are one of the answers to reversing their plight. By planting more milkweeds, monarch will find these larval food sources more readily. Milkweeds are larval host plants for Monarch and Queen Butterflies and the Milkweed Tussock Moth. Many bees, wasps, butterflies and beetles visit milkweed flowers for the nectar. Milkweed plants typically produce a lot of nectar that it is replenished overnight. Nocturnal moths feast at night and other pollinators flock to these important plants during the day. 

Choose butterfly milkweed (Asclepias tuberosa) or green antelope horn milkweed for your formal garden and common, Sullivant’s, or whorled milkweeds for the outskirts of your property. 

Newly hatched monarch caterpillar on common milkweed.

Blazing Stars (Liatris sp.)

Liatris are very important wildflowers. The vibrant purple blooms in summer support many great insect species. They are quite adaptive with different species growing in dry to moist soil conditions. There is literally a blazing star for just about every garden setting. 

I prefer Liatris pycnostachya and Liatris aspera, but many others, including Liatris ligulistylis and Liatris punctata, are nice too.    

Liatris pycnostachya

Planting just natives is not enough. Garden designs and plant communities must contain at least some keystone plants to positively impact the food web. This is the start of a list, but there are certainly more plants to choose from.  Check out Keystone Natives for the Food Web-Part 2 and Keystone Natives for the Food Web-Shrubs.

March Gardening Checklist

While March can still be cold in Kansas and we can get some significant snow and ice, there are still opportunities to spend time in your garden. Here is a March gardening checklist that will prepare your garden to thrive in the coming year.

Prune trees and shrubs

This is a perfect time to be pruning trees and shrubs. Maybe there is a branch that is always in the way while you mow, or shrubs that are encroaching on a walkway. Cut them back. Keep in mind to only prune shrubs that flower on new wood. Pruning shrubs like forsythia and lilacs will remove blooms for this spring. Spring blooming shrubs can be pruned after they are done blooming in late April or May so they have time to set new buds for next year. Check out this blog by Katie, Old Wood, New Buds: A Pruning Guide.

Don’t lose your lilac blooms, prune at the perfect time! Photo by AnRo0002 (Own work) [CC0], via Wikimedia Commons.

Cut back flower beds

Now through March is the time to trim back ornamental perennials and grass stalks to clear room for new growth. By cutting these plants back it you allow sunlight to reach the crowns and warm the soil. We have talked about it several times, but it is worth repeating – if you can help it don’t carry stalks away from your garden. Leave them as natural mulch. These stems and stalks harbor native pollinators that you want to keep in your landscape. If thatch is too thick, remove it to an obscure place in your yard or along the alley.

Northwind Switchgrass cut back and ready for spring

Apply compost to soil

If you haven’t already, empty out your compost bin and put it on your garden. Prepare your garden soil if it’s dry enough to work. Dig in compost and other amendments when your soil can be worked. Only do this if your soil is dry enough.

How do you know when it’s safe to work the soil? When a ball of soil crumbles easily after being squeezed together in your hand, it’s dry enough. With our clay soils, avoid compacting your garden soil. Wait until it’s dried out before tilling, planting, or even walking in the garden beds.

Loosen mulch

Mulch has a tendency to fuse together, especially with mulch more than a couple inches thick. This cake layer along the top resists moisture penetration and seals off the soil, restricting good air exchange. It is good each year to rough up the mulch with a fork or rake to break that seal. This will open up the soil to moisture and positive air movement. Tree and shrub mulch rings and shrub borders will benefit the most from this exercise. While you are at it, maybe a fresh layer of mulch is needed. I typically have 2-3 inches of mulch around these woody plants.

Arizona Cypress nicely mulched on a berm.

Continue to gather ideas

There is so much information available to gardeners these days. Choose plants that create habitat and attract wildlife to your yard. Review your garden journal from last year. Read horticulture magazines. Attend the lectures and presentations at your local garden shows such as the Harvey County Garden Show on March 25 and 26 here at the Arboretum.

Regardless of what season the calendar says, there is always something to do in the garden. Spring is coming, so now is the time to get ready. I don’t know about you, but I am ready to see some blooming plants again.

Yellow crocus in the xeric garden brighten a winter day

Native Grasses FAQ

After my Native Plant School class last week, there were several good questions about native grasses that are worth addressing again.

Question 1: How do you clean up native grasses in the late winter (Feb-March)?

Grasses tend to remain attractive well into winter, providing texture, movement and continuity to the garden. However, they eventually need to be cut back in preparation for spring. We use a gas powered hedge trimmer because we have so many grasses to cut back. The stems are tough but the trimmer easily cuts through them especially compared to hand pruners or loppers.

Starting at the top of the grass, we just cut through the grasses back and forth at 2-3 inch intervals until the grass is cut down to 2-4 inches off the ground. We then scatter the cuttings around the base of the grass so that it is not too thick. The trimmer makes quick work of a five foot grass. If the pile at the base of the grass is too thick, we scatter the clippings someplace else in the garden. This way you are keeping all those overwintering insects in your yard.

In our recent Winter Lecture Series, guest speaker Heather Holm suggested an even more insect-centric approach to spring garden clean up. Gain access to her presentation HERE.

Northwind Switchgrass cut back and ready for spring

FUN FACTS!

  • There are more than 400 different native bee species in Kansas.
  • An estimated 30% of native pollinators nest in pithy stems of plants such as native grasses and wildflowers.
  • Dead branches or logs decaying provide excellent habitat. Create a small bush pile for birds and pollinators. Overwintering butterflies and ground nesting bees can be found in brush piles and the decomposing wood gives fireflies a place to lay their eggs.
  • Nearly 70% of native pollinators are ground-nesting, burying into the soil to reproduce. Open soil without landscape fabric or two to three inches of mulch allow these burrowing insects to easily access the soil.

Question 2: When is the best time to plant buffalograss?

Buffalograss is a native warm-season sod forming grass. It needs at least six hours of direct sunlight for it to germinate and grow healthy. It spreads by stolens and has fine blue-green leaves. New seeded forms of buffalograss have been developed over the years such as Cody, Bison, Bowie, Plains, Topgun and Sundancer. Most of these seed forms are available online and some are available at regional Farmers Cooperatives. Seeding can be done anytime from May through August 15 as long as the soil temperatures at a two inch depth are above 60 degrees. Check out Buffalograss: Five Keys to a Successful Planting on our website.

Buffalograss Interior of Arboretum

Question 3: Can you list out the heights and mature sizes of the grasses?

One of the key components of a successful native landscape design is situating grasses. Repeating taller grasses at regular intervals looks formal while these same taller grasses at irregular intervals is relaxing and less formal. Grasses unify and blend your landscape together and they are wonderful companion plants with other wildflowers and shrubs.

  • Short= 4-24 inches, Examples: prairie dropseed, blue grama, pink muhly, sideoats grama, june grass, “Blonde Ambition” blue grama, purple love grass, and Nassella tenuissima,
  • Medium= 2-4 feet, Examples: Little bluestem, Little bluestem cultivars, Sideoats grama, Blonde Ambition blue grama, Northern sea oats, Pink Muhly grasses, “Cheyenne Sky” switchgrass, “Shenandoah” switchgrass, and sand love grass (Eragrostis trichoides).
  • Tall= 4-7 feet, Examples: Big bluestem and cultivars, Indian grass and cultivars, Eastern gamma grass, prairie cordgrass, switchgrass and switchgrass cultivars.
Indiangrass against the Kansas sky. Photo by Brad Guhr.

Songs of the Solstice

When the weather is cold and the days are short, I just want to curl up on the couch and rest. And according to prairie plants, that’s exactly what I should be doing! As much as it pains us to see our favorite plants dry up and freeze in the fall, cold weather is an essential pause in the growth cycle for some plant species. Dormancy, vernalization, and cycles of freezing and thawing are an important part of their development.

A winter sunset dips below the horizon behind a bur oak tree and a snowy landscape.
Photo by Gerry Epp

Baby It’s Cold Outside

Contrary to how we feel about it, cold weather is a very good thing for plants in our region. In fact, there are many species of plants that cannot bloom without a prolonged cold period. Apple trees cannot form proper buds without 500 to 1,000 “chilling hours”. Tulips will not bloom without 12 to 16 weeks of cold soil temperatures. And even the historically finicky peach tree will not set fruit without a proper cold spell during the winter months. This cold period for plants is called ‘vernalization’. It all has to do with needing some rest — after a strenuous growing season, many plants use the signal of dark days and cold temperatures to go into their dormant phase, an energy-saving adaptation that allows them to jump back into full blossom in the spring. Why fight the harsh winter conditions when you can just sleep through it?

On Dormancy, or Rest Ye Merry Gentle(Plants)

Dormancy is not death, it is more like a long, deep sleep. In preparation for winter, plants stop actively growing and begin to transport their sugar reserves into their roots. This means the foliage may look shriveled and dried, but the roots are more alive than ever, packed with energy to get through the winter. When they go dormant, all the internal chemical processes of the plant slow down. Isn’t that good advice for us too? Slow down, give up trying to keep up all those lush, green appearances and just focus on your roots and energy reserves! Remember to give your plants a bit of water of the winter if things get abnormally dry; they are resting, but still need moisture to stay alive until spring!

The dormant trees of the Arboretum take the spotlight during our Prairie Lights event. The lights accentuate their form and help us to appreciate them even in the off season. Photo by Amy Sharp Photography.

Let It Snow

Native prairie seeds are especially in need of cold, moist winters. These seeds have incredibly hard seed coats, called testas. The outer shell of the seed is hard for many reasons: to protect it from the elements, to prevent it from germinating too soon when conditions are unfavorable, or to survive the inside of a stomach once it is eaten and, – *ahem* – expelled. But this hard seed coat does finally break open after many freezes and thaws in a Kansas winter. Moisture works its way into the seed and helps the process along. Without deep cold, seeds would not germinate as well or at the correct time.

Seeds take many shapes and forms. Line drawing by Lorna Harder, can be found on our “Prairie Restoration” informational sign on the Arb grounds.

Winter can be a beautiful season if you know where to look. Prairie plants provide interesting textures and colors even through the darkest days of December and January. And more than being aesthetically pleasing, leaving gardens standing through winter provides the necessary habitat and shelter for wildlife to survive cold temperatures. As you enjoy your own kind of dormancy this winter solstice, I hope you find some comfort in the natural cycles of waking and rest happening all around you!