I must Stop the Mock Strawberry (Duchesnea indica)

By Wendy Diaz, EMGV

Last year, I noticed a spreading wildflower around the base of my beautyberry bushes (Callicarpa Americana) in a perennial bed along the south side of my house that I originally thought was Wild Strawberry1 (Fragaria virginiana). It appeared amongst my creeping Jenny (Lysimachia nummularia ‘Aurea’), which I was using as a ground cover. 

Mock Strawberry colony of plants covering ground of ornamental flower bed. Photo by Wendy Diaz on May 6, 2019

This year, it has taken over the bed and migrated into the lawn and even the aggressive creeping Jenny has lost its battle with this plant, which now covers every plant in the bed that isn’t higher than five inches. A lesson that I should have learned a long time ago … if the gardener ignores a few weeds in the garden, the gardener risks bigger issues in the future. The culprit, as it turns out, is a perennial weed commonly called Mock or Indian Strawberry (Duchesnea indica)2,3and not the native wildflower, Wild Strawberry4. The relatively sudden appearance of this plant in my yard is likely the result of birds eating drupes elsewhere and spreading them to my yard2.

Creeping Jenny has been covered by Mock Strawberry in ornamental bed. Photo taken by Wendy Diaz on May 6, 2019

Mock Strawberry (Duchesnea indica)

Mock strawberry is an herbaceous perennial plant of a height between three and eight inches and spreads by runners or hairy stolons3, 5 into large colonies of plants over time. Each plant consists of small trifoliate basal leaves with long petioles that develop from a root crown2. Each leaflet is about one inch across and elliptical with rounded toothed lobes5. Its five-petal yellow flowers of about 0.5-inch diameter appear in spring and develop into tiny edible red tasteless fruit or drupes that are held upright2. Small red seeds form on the bumpy surface of the fruit. It prefers moist soils and partial sunlight and can adapt to regular mowing because of its low growing habit2. It was introduced as an ornamental plant from south Asia.

Five-petal yellow flower of the Mock Strawberry. Photo taken by Wendy Diaz on June 20, 2019
Trifoliate basal leaves and red fruit or drupes of Mock Strawberry. Photo taken by Wendy Diaz on May 6, 2019

Control

To help reduce Mock Strawberry lawn encroachment, it is recommended that one improve surface drainage, aerate when needed and conduct infrequent watering5. If the gardener is interested in chemical control, the recommendation for both pre-emergence and postemergence control formulation is provided in detail on the NC State TurfFiles website5.  In my perennial bed I have decided to control it by hand weeding and mulch. 

Comparison to Wild Strawberry

Wild Strawberry or Scarlet Strawberry can make a desirable ground cover in woodland gardens with some wildlife value1, 4 and it can control erosion on slopes. Mock Strawberry is easily distinguishable from the native Wild Strawberry because its flower is yellow and the Wild Strawberry has a white flower. Other differences include lower growing and smaller leaves of the Mock Strawberry and the drupes are erect. The Wild Strawberry drupes tend to hang downward and the teeth on the leaf edges are sharp-pointed rather than rounded. Best of all, the fruit of the Wild Strawberry is juicy and with a pleasant sweet-tart taste whereas the Mock Strawberry is bland with a dry texture.

Your yard may not have ideal conditions for Wild Strawberry as a ground cover but nevertheless cultural control of Mock Strawberry is more desirable than letting it takeover your ornamental beds and crowding out more desirable lower growing plants.

References

  1. http://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=291715&isprofile=0&=

2. https://www.illinoiswildflowers.info/weeds/plants/mock_strawberry.htm
3.  https://plants.ces.ncsu.edu/plants/all/duchesnea-indica/

4. https://www.ncwildflower.org/plant_galleries/details/fragaria-virginiana

5. https://content.ces.ncsu.edu/indian-mock-strawberryor

https://www.turffiles.ncsu.edu/weeds-in-turf/indian-mock-strawberry/

Ground Covers as Weed Control

by Andrea Laine, EMGV

After several years of trying to stay ahead of the weeds in my landscaped beds, I am coming around to an option I had not seriously considered before: planting ground covers as weed control.

Weeds

A variety of annual and perennial broadleaf weeds consider my yard home year round. Most of them I deal with by manually pulling. Dr. Joe Neal, professor of weed science at NCSU, recommends a frequency of every two to three weeks. Call me crazy, but I have never minded hand weeding. It feels meditative while I am doing it and afterwards, too, when I look upon my tidy garden.

Unfortunately, hand-pulling does not work for creeping woodsorrel (Oxalis corniculata L.). Even after a good rain and using a weed digger, it is difficult to get the root up on a younger plant. I find it easier to let it grow a bit which gives me more plant above ground to grasp and pull. But allowing any weed time to mature is dicey: weeds multiply so quickly and aside from being unsightly, rob your favored plants of moisture and nutrients in the soil. Encroachment is inevitable with woodsorrel as it spreads by rhizome, stolon and/or rapidly germinating seeds.

Ground covers

I used to view ground covers as boring plantings; something you chose for a spot where it was difficult to grow anything else, or something non-gardeners or commercial properties planted to paint a spot green and call it landscaped. (Pachysandra comes immediately to mind.) But looking out my kitchen window last November at the way a few biennial columbine plants (Aquilegia canadensis) have reseeded so profusely over just a few years and now expertly cover a large part of the ground in one bed (i.e. no woodsorrell there), I am beginning to understand the concept and consider the possibilities.

ColumbineCover
Columbine isn’t traditionally considered a groundcover but it does the job nicely. All photos by A. Laine.

Ground covers are plants that grow relatively close to the ground and spread freely to create a mass planting. The denser they are, the better they will be at shading the ground, thereby robbing weed seeds or rhizomes in the soil of the light needed to grow. If desired for weed control, seek out evergreen ground covers.

Columbine isn’t traditionally considered a ground cover but it does the job nicely. Some common ground covers are already established in my landscape; pictured below left to right they are: golden creeping jenny (Lysimachia nummularia ‘Aurea’ ), creeping juniper (Juniperus horizontalis ), oregano (Origanum heracleoticum ‘Greek’ ) and Mrs. Robb’s bonnet (Euphorbia amyglaloides, ‘robbiae’).

A blank canvas

My thoughts of “too much columbine” have turned to “need more variety of ground covers.” Ground covers will be the new blank canvas. I am not choosing ground covers instead of more ornamental perennials and shrubs. I am choosing ground covers over open soil or a blanket of mulch which can be expensive and labor intensive when used for large spaces. Rather than fretting over too much columbine, I will consider it a placeholder and an organic mulch. When I am ready to plant something among it, I will simply edit out some columbine and insert a showier ornamental.

Where you have stubborn weeds, consider planting a more attractive ground cover. More plant suggestions appear in the links below.

Sources & Further Reading

About weeds

Identifying specific weeds: https://content.ces.ncsu.edu/are-you-weeding-frequently-enough-to-prevent-weeds-from-spreading

About Groundcovers

This link lists dozens of groundcover suggestions for Georgia landscapes. Almost all will also survive in Durham County (Hardiness Zone 7).  https://secure.caes.uga.edu/extension/publications/files/pdf/C%20928_2.PDF

Low-growing junipers make excellent groundcovers: https://content.ces.ncsu.edu/junipers-in-the-landscape

More groundcover plant ideas: https://www.missouribotanicalgarden.org/Portals/0/Gardening/Gardening%20Help/Factsheets/Ground%20Cover%20Plants66.pdf