Microstegium on the March

by Andrea Laine, EMGV

Typically I don’t get riled up about weeds that are easy to pull up by hand, but Japanese stiltgrass (Microstegium vimineum) is a HUGE exception. Despite its fibrous, shallow root system, in just three to five years this invasive species can overtake a natural area, pushing out natives and non-natives alike. It is also detrimental to ground-nesting birds and can contribute to fueling forest fires. I’ve observed more and more of it in local forests and parks where I hike as well as the roadsides in my woodsy Durham County neighborhood. It’s a sad sight, especially on conservation lands.   

This spring was the first time I noticed stiltgrass at a friend’s home in the Piedmont region of Virginia. Normally when I‘m there I’m grousing about periwinkle (Vinca minor) and winged burning bush (Euonymous alata), two other invasive species which I have previously blogged about. I admit to feeling a bit of poetic justice at the sight of the one invasive (periwinkle) being overtaken by another (stiltgrass). But the feeling was fleeting. Every subsequent feeling has been more along battle lines – how can I fight this?

A trio of invasive species is pictured here: winged burning bush in the background, a wide mat of periwinkle established in the foreground and now Japanese stiltgrass has joined the scene. Photo taken June 22, 2019 by A. Laine

Identification

Before attempting to eradicate any weed, you want to be sure you have identified it correctly. When I first noticed stiltgrass, its structure and wispiness reminded me of bamboo, albeit a tiny version.  

In plant ID lingo stiltgrass is a “prostrate to erect, sprawling and freely branched summer annual with spreading stems that root at the nodes … Leaves are rolled in the bud; ligules are short membranous with hairs …”1  If you’re thinking, hey what IS a ligule? Don’t despair! Stiltgrass does have one distinguishing characteristic that you need not be a botanist to recognize:  Each leaf on stiltgrass has a silvery midvein that divides the leaf unevenly

Note in the accompanying photo gallery how this feature is absent from other plants (some weedy, some not) that are often mistaken for stiltgrass.


The root structure of stiltgrass is also distinct from other weeds often mistaken for stiltgrass as noted in these photos. (Stiltgrass is the photo with the brown background.)


Growth habit and lifecycle
Japanese stiltgrass seeds germinate in early spring. The plants grow and strengthen through the summer. In June the Virginia patch was about six inches high; At the beginning of August, the plants were two to three feet tall. In NC it flowers from mid-September through October and soon after flowering the seeds are dispersed – 1000 seeds per one wispy plant! Seeds stay viable in the soil for four years.

I consulted a lot of sources before writing this post and it seems that there is not one “right place” for stiltgrass to thrive. Some sources advised sun, others shade. Some moist woodland, others dry roadsides. Apparently, it is adaptable to a variety of conditions. It will even tolerate a mild frost. And, it really makes its presence known in areas where the soil has been disturbed. This may have been a factor for the Virginia property I referred to earlier as several very large trees were felled, cut up, and carted away from the land over the last year. That kind of activity definitely disturbs soil and surrounding environment.

Would you believe there is a tree peony in the midst of this mess of Japanese stiltgrass? Photo taken August 4, 2019 by A. Laine

Understanding the lifecycle of a weed or any unwanted plant is important because in order to stop it from spreading you need to stop it before it seeds. The flowerhead on stiltgrass though is quite small as are the seeds, so best to act based on the time of year than on a visual. From now through September is a good time for those of us in Durham County to act.  

Tactical solutions
Here are three ways to combat a stiltgrass invasion. Which tactic you choose will depend upon how much stiltgrass you have, where it is growing, and your comfort level with chemicals.

Hand-pulling or digging
While this tactic is typically my go-to for weeding, it only makes sense with small infestations and even then, there are some caveats. When we pull weeds by hand, we disturb the soil which is often enough to bring previously dormant seeds to the surface where they will receive the sunlight they need to germinate. “Hand-pulling of stiltgrass plants needs to be repeated and continued for many seasons until the seed bank is exhausted.“2

Mowing
If stiltgrass is growing in your lawn (or what passes as your lawn) then mowing seems like an obvious tactic. But when stiltgrass is mowed too early in its lifecycle, the roots re-energize and send new shoots above ground more quickly than the first time and it may flower and seed earlier, too.3  If possible, delay mowing stiltgrass until the end of August to deter regrowth or seeding.

The best way to prevent stiltgrass in a lawn is to follow best practices for lawn seeding and care. To learn how to properly maintain your lawn consult NC State’s Turf files website.

Herbicide
My friend has given me complete freedom to attack the burning bush and the stiltgrass around his home, but not the periwinkle which he likes very much. After three decades it is as much a part of his mountain retreat as the cabin it surrounds. Knowing I needed to save the periwinkle, I turned to the one-percent solution. This is a tip I received from a weed control expert at a local botanical garden during an educational class. (We master gardeners need to complete at least eight hours of education each year.) Extension programs also endorse this solution.

A half to one-percent solution of glyphosate will kill Japanese stiltgrass without harming the other plants around it. Ready to spray containers of glyphosate I have purchased held an 8% solution. Concentrated varieties were 18%. I share this information to drive home the point that more IS NOT better. I suited up (long pants, long-sleeved shirt, tall rubber boots,  nitrile gloves) before mixing up a much diluted version of the herbicide and I sprayed the stiltgrass.  

Note that other herbicides are recommended for killing stiltgrass growing in a lawn. These are best applied in late spring or early summer so that the lawn has time to recover. Follow the “Dealing with stiltgrass in lawns” link under Resources to learn more.  

Weeding is a commitment
Whichever method you choose, plan on at least a five-year commitment. Since I don’t live on or near the property I treated, I won’t know the outcome of my effort until the fall. But I already understand that my work is not finished. I was working in a natural area on a mountain side. I could not reach all the stiltgrass. Hopefully, the patch of stiltgrass growing on your land is smaller, more easily accessible and responds to your chosen method of treatment.

Footnotes
1 and 2 –  Detail about the identifying characteristics of stiltgrass and list of herbicides specifically labeled for stiltgrass: https://content.ces.ncsu.edu/japanese-stiltgrass-identification-and-management#

3 – Control options for grasses and grass-like plants:  https://www.invasive.org/alien/pubs/midatlantic/control-grassesandsedges.htm

Additional Resources & Further Reading
Dealing with stiltgrass in lawns: https://content.ces.ncsu.edu/japanese-stiltgrass
Turf Files home page: https://www.turffiles.ncsu.edu/

A very good weed key:
https://weedid.missouri.edu/weedinfo.cfm?weed_id=173

Invasive Plant Species Management, Quick Sheet 4: Japanese stiltgrass, Penn State

Invasive Weeds of the Appalachian Region, University of Tennessee Institute of Agriculture.

Growing Well at the Community Garden

Continuing our topic of What’s Growing Well in the Garden, Kathryn Hamilton and Charles Murphy share stories of their successes. Both of these Extension master gardener volunteers garden at the Briggs Avenue Community Garden. They maintain their own individual plots as well as assist the community with bigger tasks. Charles minds the orchard and Kathryn minds the composting. — Andrea, Blog editor

Kathryn’s awesome year

I have had an awesome garden year. Beginning with snow peas planted in January and harvested through May, and including winter crops (cabbage, cauliflower, and broccoli) harvested through the beginning of May. The summer, though not nearly through, has been equally robust. I have totaled 191 pounds of produce. This does not include what was given away at the garden before I got to weigh it. Some of the summer highlights: 107 pounds of cucumbers; 9.6 pounds of mostly Japanese style eggplants, 17.3 pounds of zucchini, and 36 pounds of tomatoes, as of today. A new crop of cucumbers has been seeded along with a new set of zucchini, four different kinds of string beans, and snow peas which are on their way from the seed house.


Peppers lead the pack for Charles

I have had consistent good results with peppers of all sorts – green and purple bells especially, mild banana peppers and really hot cayennes – for a number of years. All my plants were set out as seedlings in April, and are producing well in mid-July.

Peppers, like many garden plants, prefer loamy, well-drained soil and the raised beds at Briggs work well. Frequent watering while seedlings are growing is good, as is a light application of a low-potency (e.g., 5-5-5 or 5-4-5) fertilizer as the plants reach mature size. Mature plants like water, but will tolerate dry conditions for longer than some other veggies, and are less susceptible to hot weather damage with temps in the low to mid 90s like we have had for the last two weeks. Bells show rich green, or other (purple, yellow) colors when ready to pick and can be used even when they are medium size. The banana peppers mature as light green fruits three to five inches long, and cayennes will turn red, but are just as spicy before they change color.

A typical picking of peppers and eggplants. Harvest every 4 to 6 days for best results. Photo by Charles Murphy

The peppers I’ve grown have had less pest damage, e.g., Japanese beetles, etc., than most of the garden crops, and tend to be low-maintenance. I’ve also had good results with the “Ichiban” variety of eggplants (caution: they are susceptible to a variety of predacious critters, so watch them closely.)  Regular watering, light fertilizing and regular cutting of fruit at six to seven inch lengths help to keep healthy plants producing longer. Peppers and eggplants co-exist in the same bed quite well, though it is a good idea to rotate planting sites from year to year.   

Other success crops for me include English peas and cucumbers. This year I put in pea seeds in early March, and could have done that earlier, expecting a mature crop in late May to early June. The variety I chose was listed as bush type on the seed packet, but I prefer to set up a trellis for the plants to climb. That makes harvest easier, and keeps pods off the ground. I chose a medium-size fruit cucumber variety (don’t remember the name), and set seedlings out in early May. Cucumbers don’t like cold weather, so wait until after last average frost date to plant. Trellised them, again to make them easier to harvest and to keep fruit off the ground. Cucumbers peas and peppers need  regular harvesting to keep fruit production going.

Learn more about vegetable gardening in central NC:

Growing Well in the Garden

It’s August and my garden (and myself) are showing signs of weariness. So I turned to my fellow Extension master gardener volunteers to find out what is growing well in their gardens. There are plant picks and care tips in the vignettes that follow to inspire us all; and if too late for this year, then definitely for next year! All photos were taken by the master gardeners.  — Andrea, Blog editor

Missouri Primrose

I seeded these indoors in early 2018 and planted outdoors after April 15th in 2018. For the past six weeks I have awakened to new blooms every morning and they have exceeded five feet in height. As a bonus the solitary pollinators sleep in them at night to be ready for the morning harvest! Missouri Primrose will have a perpetual place in my garden. – Brandon W.
 

Caladium and Coleus

My front porch plants are doing well. I have been planting caladium and  coleus every summer for 30 years. I love the combination and it also goes really well with the pink knockout roses in front of my porch. I think this year I will try to save my caladium bulbs for the first time ever. — Kerry H.

Coral bells and hostas

Coral bells (Heuchera sanguinea) loves the shady side of my house. It has thrived in this spot for about five years and never fails to surprise and delight. It’s an evergreen plant with maximum height of a foot-and-a-half and a spread of slightly less. The hostas are doing well, too!  — Carol T.

Zinnias

Almost all of the plants in my garden are perennials. For the first time since I was a child living in hot and dry Texas, I decided to plant Zinnia seeds this year- as a nod to a childhood long past. Thank goodness I did; It is practically the only flower blooming along the edges of my mostly shade garden. It is definitely drought tolerant and deer resistant and planting them will make every child feel like a successful gardener! Also, it is a simple delight to see what color might unfold on top of their tall  sturdy stalks during the course of this hot dry summer.  — Cy G.

Agastache

Both Agastache foeniculum (anise hyssop) and Agastache rugosa ‘Golden Jubilee’ are in this photo. I wish you could see the multitude of bees and butterflies that are feeding on the spiky blooms. Throughout the blistering heat wave, these plants have been alive with pollinators. This is my second year with them. They get a bit “floppy” late in the season, so I’m going to try aggressive deadheading this year and see if I get more new growth and less flop. During the hot, dry weather I make sure they get one good soaking a week. — Tina F.

Cleome

Cleome or spider flower (Cleome hassleriana) is a fragrant, sun-loving annual. Mine are still growing tall, producing blooms and lots of seeds. – Cathy L.


Lesser known

Solomon Seal (Polygonatum spp.) on left, is a native herbaceous perennial that grows well in shady areas. Quarter-inch blue-black (poisonous) berries dangle from the stem in the fall. Pictured here is one with variegated leaves. Weeping love grass (Eragrostis curvula), on right, is an ornamental grass whose leaves turn yellow to bronze in winter. It is used as erosion control on highway right-of-ways. – Beth A.

Learn more about the characteristics of each of the above mentioned plants at https://plants.ces.ncsu.edu.

Fennel

Year after year our bronze fennel is host to swallowtail caterpillars. Since rethinking our lawn care routine, the fennel has a bigger following than ever with a variety of bees, other insects and even a praying mantis who’s motives might be suspicious. The fennel is easy care with an occasional drink and it readily reseeds to keep the patch going strong. — Lynne N.

Beginner’s Luck?

My gardening interests are primarily focused on creating an aesthetic and pollinator friendly landscape, along with a few herbs. This year I decided to try a tomato plant. I bought a golden tomato shrub plant at the farmer’s market. It is doing so well! I’ve lost two tomatoes to blossom end rot, but have harvested a dozen already and have 30 more on the plant.  — Kerry H.

Tomato ‘German Johnson’

Here is one of my German Johnson tomatoes, a really sweet, pink variety. I planted some in the garden and put one plant in my homemade self-watering bucket. I really like the self-watering bucket. All month (July) I have had tomatoes. This is the first time ever I have had an indeterminate really continue bearing. It is eight feet tall and blooming. I think having uniform moisture is the best thing about the self-watering bucket. – Linda D.

Coming up on Thursday, more “Growing Well.”

Learn With Us, week of August 4

Cool Season Vegetables
Saturday, August 10⋅10:00 – 11:00a
m
Durham Garden Center
4536 Hillsborough Rd, Durham, NC 27705
Growing COOL SEASON VEGETABLES in the Triangle region presents unique challenges and rewards. Topics will include species and varieties that can be successfully raised when the tomatoes and peppers have finally finished. Planning early for late-season planting as well as the different challenges of Fall temperature, moisture and soil depletion will all be discussed. Also of interest will be techniques and materials that will abet over-wintering of certain crops as well as preparing beds in the Fall for Spring planting next season.

Free, registration required. Sign up at the store, online or by phone
Include the seminar title and full name(s) of persons attending

August: To Do in the Garden

by Gary Crispell, EMGV

Alrighty then! We survived July, just barely. Thank you, Mother Nature, for the break at the end of the month. So, how does your garden look?  And the water bill? (Ouch!) Well, July is behind us now and August is upon us with her bounty of veggies and plethora of blooming plants. Let us hope the rain gods will be less capricious and the heat stays somewhere else. Whether or not those things come about there are things to do in the garden and don’t forget to be hurricane prepared. (You know, the ones that come in off the ocean – not the ones that reside at PNC Arena.)

Lawn Care

Check the lawn for grubs. If you find some, treat with an appropriate insecticide. If you do find any, be grateful and put the sprayer away.

Late in the month prepare any areas that need to be seeded with cool season grass (tall fescue, bluegrass).

Fertilizing

Give your strawberries a shot of nitrogen fertilizer.

DO NOT fertilize trees or shrubbery until December.

Planting

Sow pansy seeds this month in flats to transplant to the landscape in September.

Perennials, hollyhock, delphinium and Stokes’ aster can be sown now for healthy plants in the spring.

Repot more house plants.

Plant a fall garden with beets, Chinese cabbage, cucumbers, kale, kohlrabi, lettuce, mustard, radish, rutabaga, squash and turnips.

Pruning

Nada. Nope. Don’t! No pruning of trees or shrubs until November.

In case of hurricane damage, disregard the above admonition.

Spraying

Same stuff as last month. Look for spider mites on coniferous evergreens (juniper, arborvitae, etc.) and lace bugs on azaleas and pyracantha.

Continue rose spray program and weekly spraying of fruit trees and bunch grapes.

Watch for worms on cruciferous vegetables (broccoli, cabbage, cauliflower) and borers on squash.  Spray only if necessary. Follow the label instructions.

Propagation

You may still take cuttings of shrubs.

More fun things to do if you just can’t get enough of the August heat

Make sure your LANDSCAPE PLAN is up to date especially if you plan to modify the landscape this fall.

Keep running up the water bill when the August thunderstorms skip your house.

Build a compost bin.

Dig Irish potatoes.

Stay cool and hydrated. September and October will soon be at hand.