Creeping Charlie does creep

Creeping Charlie, like the dandelion, is one of those perennial plants that people are constantly complaining about and battling to remove from their lawns. Otherwise known as Ground Ivy, Creeping Charlie is an ornamental ground cover that is native to the British Isles but has been seen in North America for over 200 years. It appears in almost all 50 states with the exception of Arizona, Hawaii, New Mexico and Utah. It is a member of the mint family, it has square stems and the leaves have a minty scent when crushed. When it blooms in early spring (April to May) the small, delicate, pale violet, tube-like flowers provide some nectar for bees. So what’s not to like about Creeping Charlie?

It is extremely invasive –spreading rapidly through the stems (stolons), which lie on the soil surface. Creeping Charlie spreads easily through lawns that are thin, with bare spots. Once established it is allelopathic, meaning it affects the growth of other plants, and decreases the germination of seeds. While you may tolerate Creeping Charlie in your lawn, it will not stay there for long and your neighbors may not be quite so tolerant.

Creeping Charlie grows well in moist soil in either sun or shade. Most often it gets its start in areas of the lawn under trees where grass has difficulty growing and there are patches of bare soil. Kentucky Blue Grass is hardy and performs well in most lawns in Minnesota, but requires full sun for most of the day. It does not grow well in the shade. Fine and tall fescue grasses will perform well in shade in Minnesota. Unfortunately, because of Creeping Charlie’s allelopathic properties you cannot simply overseed Creeping Charlie with grass seed; it must be removed first. If it is present in low numbers you can remove it by hand weeding, being careful to remove all of the roots. It might require several weedings, weeks apart to make sure that it’s all gone before overseeding the lawn.

If Creeping Charlie has taken over large areas other removal methods might be more effective. One method might be to use a sod cutter to remove all of the vegetation in the affected area. Make sure you are down to bare soil before you plant the appropriate grass seed for the growing conditions. A less labor intensive method of removal is solarization, but it does take a bit longer. Solarization is using the sun to kill the vegetation. Laying down large pieces of clear plastic over the affected spots captures heat and sunlight and raises the temperatures under the plastic to the point where no vegetation can survive. This method works well for areas in full sun that are smaller than 1/4 acre. If you lay the plastic in early spring all the vegetation could be gone by late summer so you can sow grass seed between August 15 and September 15 which is the optimum time to plant grass. This method will also work in shady areas but it could take 5-6 months to kill the vegetation. In this case you could try dormant seeding in the fall when soil temperatures are 35° to 55° F. This is too cool for the seed to germinate but provided the seed does not wash away it will germinate in the spring when the soil temperatures rise.

Another less environmentally friendly method for getting rid of Creeping Charlie is using a chemical herbicide. Products containing triclopyr usually give the best results, but glyphosate will also work. If you are spraying either herbicide be sure to follow all label instructions. Spray on warm, calm days to avoid any drift of the chemical onto desirable plants as the herbicide is non-selective. You may need two treatments of the herbicide 7-10 days apart to insure complete eradication of the Creeping Charlie. Once you have removed all of the dead vegetation you may want to wait a little bit longer; to ensure that all of the herbicide is gone from the soil before you spread the appropriate grass seed.

Creeping Charlie seems to be one of the nemeses of the urban lawn. If we cannot live with it, a little bit of intense work may be required to rid our lawns of it.