Last Update on Buffalograss Seeding Experiment

It has been almost a year since our buffalograss seeding experiment began.   In this new approach, we planted the buffalograss seeds along with annual ryegrass in the fall or early winter.  In theory, the annual ryegrass, a cool season grass will germinate and hold the soil through the winter.  The buffalograss seeds will work their way into the soil with the natural freeze/thaw of the soil throughout the winter.  These seeds will then germinate on their own the following spring with annual rainfall and warm 60 degree soil temperature.

Last fall I prepared the soil as if I was planting fescue so the annual ryegrass seed would germinate with daily watering.  This loose seed bed helped the annual ryegrass to germinate in about a week or ten days.  This method flipped the traditional buffalograss seeding upside down.  Typically, I have areas prepared to plant buffalograss in May and June.  Buffalograss it is a native warm season grass that needs to be planted when soil temperatures are above 60 degrees.

Update

I have been pleasantly surprised.  The little buffalograss seedlings have started to spread in amongst the crabgrass and knotweed.  I believe it will begin to overpower these weeds and completely cover the areas next year. 

Buffalograss seedling that have started to spread

I may look at putting a preemergent herbicide down next spring to give the buffalograss less weed competition.  This is primarily to control summer annuals such as crabgrass and foxtail. Barricade (prodiamine), Pendulum Aquacap (pendimethalin), Dimension (dithiopyr), Specticle (indaziflam) are recommended pre-emergent herbicides on established Buffalograss stands. Read and follow the chemical label application instructions for best results.  Pre-emergent herbicides can also be applied in the fall to control that pesky weed, little barley.

When asked if I would do this buffalorass planting method again, I would say yes.  For small areas of 1000 sq. ft or less, it makes sense and saves so much water.  For larger areas, I think it is a toss-up.  I think it will be successful either way.  Of course, summer seeding take at least daily watering for the first 10-14 days to get the seed to germinate.  For large areas, this obviously requires so much water because the soil dries out quickly with wind and heat.  I think you can be successful with either method but I really liked using less water overall. 

We encourage people to use buffalograss in areas that receive at least six hours of sunlight each day throughout the year.  Newer varieties are vigorous growers and require little to no water once established. Compare that to a traditional fescue lawn, which needs one to two inches of moisture per week to keep it alive in the summer. These newer buffalograss forms stay green longer in the fall and green up earlier in the spring.  If kept relatively weed free, they require less frequent mowing. Buffalograss needs little to no fertilizer and will reduce your overall maintenance.

Small buffalograss seedling

Reasons to Leave Ornamental Grasses In Winter

The use of ornamental grasses in the landscape has become more popular than ever, and for good reason. The allure of ornamental grasses is that they are tough and easy to grow. Their resilient nature reflects our prairie landscape in our own garden. They are a nice visual contrast to many other plants like perennials, shrubs, trees and even other grasses. A bonus is the beauty and movement they add to the winter landscape.

Liatris and Indian grass in the Prairie Window Project

One of the questions we get this time of year is whether or not to cut ornamental grasses back to the ground for winter?

In the fall, ornamental grasses are in their full regalia with their attractive seed heads. From short to tall, these grasses put on quite a late season show. As we transition into fall, the colors they develop are another reason we use them in our landscapes. However, these fall colors fade and we are left with dull shades of tan and brown. Is it best to leave these grasses now or remove them? Generally, we leave them through the winter, and cut them back before they begin to grow next season. In Kansas, this task can be done in late February to early April.

Here are some of the advantages of leaving grasses for the winter and waiting until the spring to cut them back

  • Grasses provide form and texture in the stark winter landscape of withered perennials and deciduous shrubs. These qualities stand out in the frost or snow and low winter sunlight.
  • Mix well with perennial wildflower seed heads
  • Provide movement in the garden. The tawny stems and seed heads move with the gentlest breeze.
  • If used as a screen, they can be left up just before they start greening up again in the spring.
  • Most native grasses can provide habitat and shelter for birds and other small animals along with overwintering sites for insects and pollinators.
  • By waiting to remove the previous year’s growth until late winter, the crown of the grass is more protected from the elements.
Little Bluestem and Coneflower Photo by Emily Weaver
Switchgrass capturing snow

How do I cut back my grasses?

After leaving the stalks up through the winter, they are drier, more brittle, and easier to cut back. I like to cut tall grasses like switchgrass and big bluestem down to about 2-3 inches off the ground. I do this with a hedgetrimmer by moving it back and forth across the stalks a few inches at a time. We used to completely remove these stalks and haul them away. Now, we let the clippings lay as mulch around the plants. These stalks may still have overwintering pollinators in the stalks that are left in the garden for next season. By spreading the cut stems around as mulch it helps to break down more quickly too. I shape smaller grasses like prairie dropseed with a pruner or hedgetrimmer. Again, I like to cut them back to two to three inches from the ground.

Over the years, we have found it very beneficial to leave ornamental grasses standing for the winter. You’ll be creating a habitat for birds, insects, and small animals. The rustling grasses will remind you of the successful season past and the promise of spring yet to come.

Switchgrass cut back in late winter ready for spring

Plant Profile: Black-eyed Susan

Black-eyed Susan (Rudbeckia sp.) are one of the most recognizable summer-blooming wildflowers. Their bright yellow flowers explode in the summer and are covered with all sorts of pollinator activity. Bees, flies, butterflies, and beetles feed on its nectar and pollen. The fruiting heads also provide seed for birds over the winter.  Here is a look at a few species and cultivars worth trying.   

Missouri black-eyed susan (Rudbeckia missouriensis)

In the wild, Missouri Black-eyed Susan grows in rocky limestone glades, barrens, and tallgrass prairies. It ranges from Illinois and Missouri, south to Arkansas, Oklahoma, and Texas. Although not native to Kansas, I have found it very resilient and quite adaptable to various growing conditions. It has large bouquets of bright yellow flowers atop 18” stems. The foliage is narrow with the leaves and stems covered with a dense fuzz. It’s a nice addition to the front/middle of any border or informal meadow landscape. 

Missouri Black-eyed Susan

Brown-eyed Susan (Rudbeckia triloba)

This native gem can be found in eastern Kansas and on into much of the southeastern Great Plains. It grows naturally in open woods and savanna areas with medium to moist soil. Each plant can produce loads of charming, warm yellow daisy flowers with brown button centers. It keeps pumping out blooms through much of the later summer through fall. The slender branched stems are surprisingly sturdy and help the plant reach an ultimate height of three to four feet. It is a wonderful habit plant with blooms for pollinators and seeds for birds. It does self-sow, so know that it will move around. You will need to selectively weed plants out of your landscape, if you are agreeable to that sort of thing. 

We have carried a cultivar of Brown-eyed Susan called ‘Prairie Glow’ with attractive flowers of burnt orange with yellow tips surrounding a chocolate center cone. ‘Prairie Glow’ prefers full sun to light shade, and is also adaptable to many soil conditions.

Brown-Eyed Susan

Sweet Black-Eyed Susan (Rudbeckia subtomentosa)

Sweet black-eyed Susan grows throughout much of the central and eastern Great Plains in low, moist soil of thickets, creek banks, pastures, prairie ravines and ditches. The flowers are spectacular and rival sunflowers in quantity of blooms, if the root system can find consistent moisture. A large variety of insects love the nectar and/or pollen of Sweet Black-eyed Susan and flock to the blooms during July, August and September. 

This is a great plant for a full sun to part shade location, but only when there is ample moisture. It will not endure dry soils. Plant it by a stream, water garden or pond where water is available on or near the surface. ‘Henry Eilers’ is a nice cultivar discovered in Illinois as a stabilized mutation with rolled or quilled ray petals. This cultivar reaches five feet tall and two feet wide. ‘Little Henry‘ is a shorter form which grows 3 to 4 feet tall but has the same quilled flowers.

Photo courtesy of TERRA NOVA® Nurseries, Inc.
www.terranovanurseries.com

Black-Eyed Susan (Rudbeckia hirta)

There are many forms of this poor man’s daisy, because it is so easy to hybridize. Typically, the species is found in full sun to part shade in mixed and tall grass prairies as a short-lived perennial or annual. It seeds readily and is a favorite to include in many prairie seed mixes. The bright yellow blooms from June through September are a welcome sight in any landscape from prairie to wildflower seeding. Some cultivars available are ‘Cherry Brandy, ‘Prairie Sun’, ‘Cherokee Sunset’, ‘Indian Summer’, ‘Autumn Colors’, ‘Denver Daisy’, ‘Goldilocks’, ‘Goldrush’, ‘Rustic Colors’, ‘Sonora’, ‘Toto Gold’, and ‘Toto Lemon’.

Cutleaf Coneflower (Rudbeckia laciniata)

This species grows in similar habitats to sweet coneflower – moist soil of creekbanks, thickets and open woods. A cut leaf coneflower really stands out in full sun and adequate moisture. The leaves are deeply lobed and the large, wide clumps, two to four feet across, can reach five to six feet tall.  Each stalk can have multiple large flowers with a greenish-yellow central cone. They bloom from July to October.  A garden worthy cultivar of cut leaf coneflower is ‘Herbstonne’.

Orange Coneflower (Rudbeckia fulgida)

This eastern United States black-eyed susan is one of the most widely used in horticulture. Many cultivars, varieties and subspecies are incorporated into landscape designs. The native form thrives in glades, meadows, and prairies.  Rudbeckia fulgida var. deamii, Rudbeckia fulgida var. fulgida and Rudbeckia fulgida var. speciosa are two of my favorite native forms of orange coneflower. They grow well in landscapes with medium to moist soil and plenty of sun. These clumps slowly spread by rhizomes ultimately forming a dense mat of dark green leaves. The blooms pop up from July through September. 

‘Goldsturm‘ was a popular cultivar, but it has been used less because it has issues with septoria leaf spot and powdery mildew. New forms like ‘American Gold Rush’, ‘Little Goldstar, and ‘Viette’s Little Suzy‘ have resistance to both septoria leaf spot and powdery mildew. These are great alternatives to ‘Goldsturm’. 

Rudbeckia ‘American Gold Rush’

Giant Coneflower (Rudbeckia maxima)

Prairie Dropseed (foreground), Rudbeckia maxima, and yellow coneflowers

I love this coneflower for its blue green leaves and large coned flowers in June and July. It makes quite a statement in the landscape with flower stalks to six feet.  Native to Texas, Oklahoma and Louisiana, I have found it to be quite adaptable. It appreciates regular moisture but can handle some dry periods.  Birds eat the seeds from the large cones during the winter. 

There is a Rudbeckia for just about any landscape situation with full to part sun and wet to dry. Pollinators love them and birds too. Add some to your garden for their late season bloom.

Plant Profile: Columbine

As I put together lists of plants according to the season that they bloom, I often come up short on spring blooming plants. In a prairie, many plants are slow to get growing in the spring until warmer temperatures spur growth.  One of the more tried and true spring blooming perennials I like to include on my lists, especially in partial sun areas, is Aquilegia canadensis, or columbine.

The Columbine flower

Columbine is one of the most popular plants for shade.  However, it grows quite well in sunny spots with morning sun and afternoon shade.  This spring blooming (May-June) woodland native is essentially two flowers in one! It has an inner yellow flower surrounded by a delicate spurred outer flower. These nectar-rich blooms are a favorite of butterflies, other pollinators, and even hummingbirds in the spring. 

The typical red/yellow flower of our native columbine

The name

Its scientific name and common name reference a couple of birds. The genus name Aquilegia comes from a combination of the Latin word “aquila” (meaning eagle for the five spurs resembling an eagle claw) and the Latin word for “columba” (meaning dove, for five doves nestled together).

The leaves

The blue-green foliage elongates in the spring, with reddish stems topped by the elegant flowers. After blooming the stems dry. I like to cut back these flower stems to the rosette of foliage.  If you leave the flower stems, the brown capsules, full of black seeds, will fall and seed themselves in your garden for next season. Occasionally, the foliage will be infested with leaf miners. Simply cut the foliage back to remove the unsightly leaves and let it regrow a new rosette of lobed leaves. Then you can distribute the seeds in other areas where you would like some more plants.

Caring for Columbine

Columbine is easy to establish in partial sun to full shade conditions. It is quite adaptable, growing in wet to medium dry soils.  It makes a nice combination with golden alexander, blue star, false sunflower and sky blue aster. A pink version of Aquilegia canadensis was actually discovered in Marion County, Kansas by the late Al Gantz and introduced by Dyck Arboretum of the Plains.

Beautiful pink columbine flower from Marion County, Kansas

As you put together your plant list for a design or matrix planting, don’t overlook the obvious. Columbine is a wonderful woodland wildflower that should be brought out of the shadows. Include it in your design as a filler to add an early pop of color in the spring in your partial shade/sun site.

Coneflowers: A Lesson in Host Plants

Coneflowers are so emblematic of the prairie. I love to include these prairie denizens in many of my designs. They are quite adaptable and I love the yellows, purples and pink colors of the true natives as they bloom during the summer.  The new cultivated varieties are attractive too. A mass of coneflowers with little bluestem make a nice combination by providing color and texture through the growing season. But right now, many of the plants are full of little black or brown caterpillars that are using Echinacea and Rudbeckia as their food.

Coneflowers as host plants

We are getting calls from our members and customers, and are seeing damage on our plants as well. Coneflower leaves are blackening, getting holes and disappearing. Contrary to how you may feel, this damage is an indication that your garden is functioning properly. Host plants are the vital food source that caterpillars live on. Adult butterflies will seek out these plants to lay their eggs on because they know that the caterpillar cannot travel far and will not survive if placed on a plant that they cannot eat. These caterpillars will eventually turn into checkerspot butterflies or a relative in that family. 

Think differently about your landscape

One of the goals of any garden – besides beauty – is to have pollinators in your garden. Sometimes they might not immediately be in the form you desire. Sometimes pollinators or their caterpillars may eat your plants or deform them.  Don’t be too hasty to spray or remove the culprits. They are doing what comes naturally to them and it is often better to leave the insect. These insects are fantastic food for fledgling birds as well.

Understand the life cycle

The caterpillars eating your coneflowers will make cocoons in a week or so and then turn into butterflies.  We must learn to embrace these caterpillars and accept some damage. The coneflowers will eventually recover. The tradeoff is that we create habitat suitable for butterflies to complete their life cycle. The “ugly, hairy” caterpillars will morph into beautiful butterflies that are equal to the beauty of the flower. 

The key to a successful butterfly garden is to plant both nectar and host plants, so that the butterflies will have a food source in all stages of their life cycles. We often design our landscapes as nectar sources and forget that these pollinators need host plants too. So as you design your landscape, include flowering plants that produce nectar and also double as host plants.

Other host plants

  • Black Eyed Susan (Rudbeckia hirta) Host plant for: Silvery Checkerspot, Gorgone Checkerspot, Bordered Patch butterfly
  • Aster spp. Host plant for: Pearl crescent, Painted Lady and more
  • Coneflower (Echinacea spp.) Host Plant for: Silvery Checkerspot and more
  • Hollyhock (Alcea spp.) Host plant for: Painted Lady, Common Checkered-Skipper and more
  • Golden Alexander (Zizia aurea) or Dill (Antheum graveolens) Host plant for: Black Swallowtail, Anise Swallowtail and more NOTE: The Black Swallowtail will feed on any plants within the Parsley family.
  • Sunflower (Helianthus spp.) Host plant for: Silvery Checkerspot, Painted Lady and more
  • Milkweeds (Asclepias spp.) Host plant for: Monarch
  • Mallow (Malva spp.) Host plant for: Common Checkered-Skipper, Gray Hairstreak , Painted Lady and more
  • Violet (Viola spp.) Host plant for: Great Spangled Fritillary, Variegated Fritillary, Meadow Fritillary and more

Wetland Wildflowers

With the recent rainfall, I have been reminded that native plants are a wonderful and underused means to create a natural setting around a water feature or low area in your landscape. Most prairie wildflowers and grasses don’t do well in soggy soil and excessive moisture results in rot and other deadly diseases. However, there are a handful of plants that grow in wet areas within a prairie or along pond margins. These wetland wildflowers appreciate wet feet and some even thrive in standing water. Rather than radically altering the drainage of a soggy, poorly drained site within your garden, try some of these plants that grow well in such conditions. 

Swamp milkweed (Asclepias incarnata)

As the name implies, swamp milkweed prefers wet locations in full sun to partial shade. Here at the Arboretum we have it growing next to the pond and stream. In the wild, it is found in prairie seeps and potholes, at the edges of marshes, and in wet ditches. Swamp milkweed grows 3 to 4 feet tall and blooms from July, August and early September. The vanilla-scented flowers are typically pale pink to rose-purple and are a favorite for migrating monarchs. 

Swamp Milkweed in bloom

Joe Pye weed (Eutrochium maculatum)

This tall, native perennial is found in moist meadows and marshes. The attractive leaves and purple spotted stems fill out this 6 foot tall wildflower. The rosy-pink bloorms in mid to late summer are a favorite of many pollinators. Joe Pye weed performs best in moist to wet soils in full sun. Smaller forms like ‘Baby Joe’ and ‘Little Joe’ are nice alternatives if you don’t have much space. 

Eutrochium maculatum ‘Gateway’

Blazing Star- (Liatris sp.)

You don’t typically think of blazing star as a wetland wildflower, since most species prefer dry sites. However, there are several species of Liatris that can handle wetter conditions. Kansas gayfeather (Liatris pycnostachya) and dense blazing star (Liatris spicata) are typically found in moist prairies and meadows. These blazing stars grow 3 to 4 feet tall with narrow, lance-like leaves and blooms in mid- to late summer.  The pinkish purple flowers grow on 12- to 18-inch-long, upright spikes.  Flowering begins at the top of the spike and moves down the stem.   

Liatris pycnostachya and gray headed coneflower on the pond edge

Other wetland wildflowers

  • Acorus calamus – Sweet Flag
  • Actinomeris alternifolia – Wingstem
  • Aster novae-angliae – New England Aster
  • Eupatorium perfoliatum – Common Boneset
  • Filipendula species – Meadow Sweet
  • Galium odoratum – Sweet Woodruff
  • Helenium autumnale-Helen’s Flower
  • Helianthus angustifolius – Swamp Sunflower
  • Hibiscus species – Rose Mallow
  • Iris virginica – Southern Blue Flag
  • Lobelia cardinalis – Cardinal Flower
  • Lobelia siphilitica – Blue Cardinal Flower
  • Mertensia virginica – Virginia Bluebell
  • Monarda species – Bee Balm
  • Physostegia virginiana – Obedient Plant
  • Pycnanthemum tenuifolium – Narrow Leaved Mountain Mint
  • Ratibida pinnata – Gray headed Coneflower
  • Senna hebecarpa – Wild Senna
  • Thalictrum dasycarpum – Purple Meadow Rue
  • Tradescantia sp. – Spiderwort
  • Verbena hastata – Blue Vervain
  • Veronicastrum virginicum – Culvers Root
  • Vernonia noveboracensis – Ironweed

Native grasses are quite adaptable, but several grasses and sedges can grow well in moist to wet soils. Big bluestem (Andropogon gerardii), switch grass (Panicum virgatum), prairie cordgrass (Spartina pectinata) can be found in roadside ditches, prairie bogs, and along pond edges. There are many native sedges such as gray’s sedge (Carex grayi) that perform well in moist soils in partial to full sun as well. 

If there’s a drainage problem in your yard, you may be inclined to install a dry creek bed or a French drain. But don’t be too quick to go to all that work. An alternative route is to simply use plants that prefer to live in wet areas. Match plants that are native and naturalize in wet conditions. Wetland wildflowers have adaptations to grow in wet soil, so they are effective landscaping solutions for areas with drainage issues.

Wildflowers for Low Maintenance Areas

When you mention wildflowers, people tend to visualize broad swaths of colorful flowers growing in meadows. This effect is often very difficult to achieve because of problems with soil preparation, plant establishment, weed control, and long term maintenance. Finding a solution to these problems usually requires more time and effort than most people want to invest.

Black-eyed Susan (Rudbeckia hirta)

Many wildflowers can be naturalized in low maintenance and unmown areas where they can reseed themselves or spread via roots. Black-eyed susan (Rudbeckia hirta) is a good candidate for naturalizing. Common in Kansas, the bright yellow ray florets with the characteristic brown, domed centers are a familiar site in June and July. Black-eyed susan is a vigorous biennial to short lived perennial that self-seeds readily. It will thrive in low a maintenance area with little care. 

Black-eyed Susan

Clasping coneflower (Dracopis amplexicauslis)

This annual grows 18-24 inches tall and produces masses of large yellow flowers from late May well into July.  The flowers are similar in appearance to black-eyed susans, but the ray flowers tend to droop downward. Also, they often have a dark red-brown band near the base of each individual ray floret. Clasping coneflower, a copious seed producer, thrives in clay soils and will often form dense colonies in moist soils. In late May and June, it is very showy in low fields and ditches in the Flint Hills of southeast Kansas.

Showy evening primrose (Oenothera speciosa)

This somewhat sprawling to upright perennial is common along roadsides in central Kansas. While white is the most common color, pink flowered forms can be found in this area as well. It generally blooms heavily from mid-April into June and then produces sporadic blossoms throughout the summer and fall. It seeds readily but usually takes two years to produce blooms. Here at the Arboretum, we have both the pink and white forms that produce a solid mass of flowers for over six weeks in the spring.

Showy Evening Primrose Photo by Emily Weaver

Mexican hat (Ratibida columnifera ‘Red’) and yellow columnar coneflower (Ratibida columnifera)

Typically, these upright clump forming perennials have abundant red tinged or bright yellow daisies with drooping ray petals around a prominent central cone – resembling a sombrero. The flowers are pollinator magnets, providing weeks of color and insect food. These wildflowers perform best in full sun and medium to dry moisture.  The attractive seed heads add late season interest and birds seek out the seeds in the fall and winter. 

Columnar coneflower photo by Emily Weaver

Other wildflowers

  • Bee balm, Monarda fistulosa
  • Leavenworth eryngo, Eryngium leavenworthii
  • Willowleaf Sunflower, Helianthus salicifolius
  • Maximillian Sunflower, Helianthus maximilianii
  • Common milkweed, Asclepias syriaca
  • Showy goldenrod, Solidago speciosa
  • Canadian goldenrod, Solidago canadensis
  • Grayhead coneflower, Ratibida pinnata
  • New England Aster, Aster novae-angliae
  • Hoary vervain, Verbena stricta
  • Blue vervain, Verbena hastata

All of these species are true wildflowers. They are aggressive, thrive with neglect and will continue to reseed and spread for many years. We recommend planting them from seed in late fall or early winter. Other desirable wildflowers can be added to these natural areas but do not try to plant these in your perennial border among your garden variety perennials and annuals. They will soon take over. They are best left to brighten the wilder areas of your yard and garden. Enjoy them from a distance.

Tree Stress

This spring we have several trees showing signs of stress that are not particularly attractive.  Since last fall, something has happened to them.  They leafed out late and/or they have some dead branches throughout the tree.  More than likely, it is a result of the historic cold temperatures this winter.  But it made me wonder about some other reasons these trees may be stressed this spring. 

Why trees?

Trees in Kansas are a luxury and one of your property’s greatest assets. To sit under a mature tree on a warm afternoon, enjoy the blue skies and sip your favorite cool drink is a special experience.

Trees need to withstand the rigors of the climate. Trees block harsh winter winds, give you privacy, delineate boundaries, offer great fall color, attract birds and other wildlife that enhance your enjoyment or your landscape, and increase its resale value. Trees are important for all of these reasons and more, but they are not invincible. At any moment, signs of stress can emerge, so we need to understand and make every effort to alleviate problems that may arise. 

Open-grown burr oaks are wider than they are tall (Photo by Lamar Roth)

Tree Stress Symptoms

Stressed trees are easy to pick out in the landscape. Symptoms will manifest in a number of ways including flaking bark, secretions, distorted or missing growth, insects, foliage issues, dead branches and lack of vigor. 

These symptoms are visual clues to internal, external or environmental stressors. Left untreated, these stressors could ultimately kill your tree. Stressed trees are beacons to insects because they are weaker and vulnerable to attack.  Compounding factors over a number of years from the same stressors or multiple stressors lead to tree fatality. Here are some common causes of stress in trees. 

Poor Tree Watering Techniques  

It is true that trees need water to survive, but they need just the right amount of water.  Too much or too little can cause a tree to be under stress. These problems can be compounded when planted in our clay soils. Defoliation, yellowing of the leaves and branch die back are all symptoms to avoid. Most trees, if properly situated, can withstand seasons of drought without much extra inputs. 

Monitor trees during stressful times such as drought to make sure they don’t need a deep soaking. Keep in mind that waterlogged soils are more problematic than drier soils because proper air exchange by the roots in hindered by extremely wet conditions. Sometimes we see a tree under stress from drought and do more damage by giving it too much water. Give it a deep soaking, but let it dry out between watering.   

Install the tree properly 

One of the first lessons I learned as a novice horticulturist is how to plant a tree. “How hard can it be?”, you may say.  Just dig a hole, put it into the ground, water it for a while and watch it grow. More trees are killed by improper installation than you might realize. Choosing the right tree for the soil conditions, along with understanding mature size, will go a long way to helping that tree survive and thrive. 

In our clay soils, I plant the root flair a few inches higher than the soil line in a hole that is at least twice the size of the root ball. I make a small basin around the tree that makes it easier to water and then lightly mulch the basin. It is important to keep mulch away from the trunk of the tree. I stake the tree for the first year and remember to remove the wires that will eventually girdle the tree if forgotten.

For some additional tips on how to properly plant trees, check out my blog post “Steps to Planting a Tree”.

Beware Lawn mowers and Weed eaters

Anything you can do to keep mowers and weed eaters away from the trunk of trees is vitally important. I have seen too many tree trunks damaged by mowers bumping them and people string trimming around the base of the tree, trying to cut down every sprig of grass. A small two to three foot mulch ring provides just the right buffer between the trunk and lawn.  I have seen a string trimmer completely girdle the soft bark of a maple tree and kill it in a couple weeks. If you have invested in a tree, protect it from these tree killers.   

Mulch Around Trees Properly

The advantages of mulch around trees are obvious. It is one of the easiest things to do and it improves the aesthetics of the landscape. However, too much mulch, mulch touching the trunk, or mulch volcanos around your trees could cause major tree stress. These stressors are totally avoidable with one to two inches of mulch around the trunk, but not touching the trunk. It is important to keep the mulch several inches away from the trunk. Too much mulch will cake up and seal off the soil, impeding proper air exchange by the roots.    

Too much mulch piled up at the base of the tree can lead to fungus, rot, low oxygen levels and tree death.
This is an example of a mulch volcano. Be sure to pull mulch away from trunk of tree and spread out.

Improper Tree Pruning

Pruning your trees as they mature is a necessary function. I generally prune our deciduous trees during the winter when they are dormant, making sure not to remove more than 1/3 of the growth at a time. Proper timing will allow the tree to begin to heal without opening up the tree to potential diseases and pests. Evergreen trees can be pruned any time but I avoid the hottest part of the year.   

Construction Injuries to Trees 

Trees often suffer during and after construction projects. Compacted soils and branch or trunk damage can stunt the growth for several years after the project has been completed.  It often takes years for compact soils to improve.  I killed several nice maple trees after our Visitor Center was constructed because the soil was too compacted.  The soil would not drain and they were essentially planted into an undraining bowl.  The roots were completely surrounded by water and they drowned and stunk when I pulled the dead trees out.  Remember to protect/ fence off any trees you want to save during a construction project. 

Environmental Injuries

There are so many nice trees and shrubs from which to choose. We often push the hardiness zones to grow trees that are borderline hardy in our area. As I mentioned earlier, we have a sawtooth oak and gingko that suffered damage from the extreme cold earlier this year. The are coming out of it, but they will look tough for a few years. These trees are not native and remind me to choose native plants first. It also reminds me to be aware of the hardiness of plants we install. Match plants up to your site, including sun, soil, exposure, hardiness, mature size, and moisture.

Sawtooth Oak winter damage

Trees are resilient, but we can help them by considering their needs. A little homework before planting can alleviate problems through the years. Trees are alive and ultimately affected by so many factors, some of which are out of our control. Who know what the next pest will be? Who knows when the next drought will occur? All we can do is try to create/match an environment conducive to growth.

Buffalograss Seeding Experiment Update

Last November, I set out to establish buffalograss a different way than I have traditionally done. Normally, I have areas prepared this time of year for buffalograss seeding. May and June are considered the best time to plant buffalograss because it is a native warm season grass.  It needs to be planted when soil temperatures are above 60 degrees.

In South central Kansas, it is recommended that seeding of buffalograss be completed no later than August 15. Later seeding is not very successful because the newly germinated seedlings do not get fully rooted before winter. That has been a good rule of thumb, but requires so much water in the summer to get the seeds to germinate.

With this new approach, one plants the buffalograss seeds along with annual ryegrass in the fall or early winter. In theory, the annual ryegrass, a cool season grass, will germinate and hold the soil through the winter. The buffalograss seeds will work their way into the soil with the natural freeze/thaw of the soil throughout the winter. These seeds will then germinate the following spring on their own with annual rainfall and warm 60 degree soil temperature. 

Area before planting, November 2020
Annual ryegrass mowed for the second time this spring.

Update

The buffalograss is starting to germinate. I have not irrigated it this spring, which is a huge time and money saver.   Over the next few weeks, I will monitor it for dryness. Beneficial and timely rains have allowed the seed to germinate on its own. Essentially, this process mimics the natural seeding process. 

In the center of the image, is a buffalograss seedling.

We are mowing the annual ryegrass weekly.  It is important to keep the canopy open so the sun warms the soil, allowing the buffalograss seeds to continue to germinate. The seeded annual ryegrass will expire on its own as we move into warmer summer temperatures. As the ryegrass dies, the roots continue to hold the soil. Buffalograss will then be able to spread and fill in the area through the rest of the summer.

What I would do differently

  • Reduce the seeding rate of the annual ryegrass: It is recommended 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 would have been better to get the annual ryegrass established with slightly warmer temperatures, but not so warm that the buffalograss seed germinates. 

I will continue to monitor the progress of the buffalograss planting.  For smaller areas this seems to be a viable alternative to the traditional buffalograss planting. There are additional costs with the purchase of the annual ryegrass seed, but you save so much time and water compared to the traditional seeding method. Look for another update on the buffalograss seeding in a couple of months as the buffalograss begins to spread.     

Weed Profile: Dame’s Rocket

As stewards of our landscapes, we need to be constantly vigilant as we monitor for problematic weeds and invasive species.  We have some usual culprits such as bindweed, bermuda grass, Johnson grass and Bradford pear trees.  However, I have noticed another subtle spreader that is quite attractive but quite pushy – Dame’s rocket. 

For years, I have been monitoring a growing population of Dame’s rocket in one of our bordering hedgerows.  It is beautiful right now with its bright purple blooms, but don’t be fooled. This desirable plant will wreak havoc on the natural environment if left unchecked.  Larger populations will even threaten the survival of native plants and degrade habitat and water quality.

Dame’s Rocket in full bloom

Dame’s rocket (Hesperis matronalis) is a tall, annual, biennial or short-lived perennial, which produces either white, pink or purple flowers in the April and May. It was introduced to North America in the 1600’s from Eurasia. The attractive blooms have made it a garden favorite. It is often seen in roadside ditches, hedgerows, older farmsteads. However, in recent years, Dame’s rocket has gone rogue, moving from yards and garden plantings into adjoining landscapes.

Phlox’s Doppelgänger

From the Mustard family (Brassicaceae), this weed resembles tall garden phlox in height and color. However, Phlox is in the Phlox family (Polemoniaceae). Perhaps the most distinguishing difference between the two is that Dame’s rocket has four petals, while phlox has five. As part of the mustard family, it produces an abundance of seed. These seeds are dispersed by mammals and eaten by birds. When the seed pods ripen, they shoot seed in all directions, including the coats of wildlife. These mammals unknowingly spread the seed to nearby waterways, hedgerows, pond edges, and maybe your landscape. Dame’s rocket is reported in most states equal or north of Kansas longitudinally. It is reported as invasive in CO, CT, IN, MD, MI, NJ, PA, TN, VA, WI, and WV.

Dame’s rocket spreading from it’s original colony

Dame’s Rocket is closely related to other problematic weeds of the mustard, family such as garlic mustard, hedge mustard, wild radish and yellow rocket. All of these weeds are prolific and opportunistic, infesting field margins, woodlands, open grassland and wetlands.  It appears to have allelopathic tendencies (the ability to produce chemicals that prevent or reduce the growth of other plants) similar to garlic mustard. With these tendencies, Dame’s rocket and garlic mustard will quickly form dense monocultures within a few years, pushing out other desirable native plants.  As has happened to our little planting, it quickly colonizes by spreading in every direction. 

Garlic Mustard

Controlling Dame’s Rocket

To control Dame’s rocket, pulling before it produces seed is the best option if the population isn’t too large.  Make sure to remove the whole plant roots and all. Discard the plants in the trash. 

Spraying is another option with a 2,4-D product. A systemic herbicide applied as a foliar spray can be effective. Herbicide is best applied to the basal rosettes (low round clumps of leaves) in late fall or early spring, when other plants are dormant. Always read and follow the directions on the label when using herbicide. Any plan must also be mindful of desirable native plant species and habitat conditions in a targeted location that may be vulnerable to herbicide uses. This is a reason to spray as a last resort. Cutting or mowing can also prevent seed production and spread until other management techniques can be initiated.   

Over the past few years, I have changed my tune regarding Dame’s rocket. As beautiful as Dame’s rocket may appear, it is an invasive species with the potential to damage entire natural ecosystems. I used to say, it is doing no harm growing in the hedgerows. Those are just waste areas that need a little beautification, I thought. Then I started seeing it in other small populations away from the original colony.  Be on the lookout for it and take action before it spreads and really becomes a problem in your landscape or your neighbors landscape.