Weeds Growing in Sidewalk Cracks

(Question)

Hello – I have an annoying issue with weeds (plaintain, creeping charlie, etc.) that thrive in the cracks in the sidewalk in front of my house, and the spaces between the edges of the sidewalk and a low stone wall at the edge of my lawn, and between the curb and the road surface. Digging these out takes hours and is back-breaking, and I balk at having to weed my sidewalk! But of course if I don’t it looks terrible. I want to plant something in the cracks myself to foil the weeds or at least reduce them. Can you suggest some plants that might work to choke out the weeds? It’s dry, very sunny, and anything in the cracks on the public sidewalk would have to be very low because of the foot traffic. Also, because the space is so very narrow, I can’t figure out how to transition a plant from a 4″ plastic pot into a narrow crack without destroying its roots, so would I actually have to start from seeds?? I would be very grateful for your suggestions! Thank you so much,

(Answer)

Thank you for your inquiry. Creeping Charlie, (Glechoma hederacea,)  is an invasive perennial weed that vines throughout lawns and chokes out grass. It spreads by seed. The best way to control it  is by hand pulling and hoeing and the key to effective control of ground ivy in gardens is persistence. But the vining stems root at their nodes so it is difficult to dig out or remove by hand because a small piece of vine will sprout again.

One of the best low growing ground covers that can be walked on is creeping thyme  (Thymus serpyllum) which  forms a dense cushions 5 to 10cm tall. The stems creep along the ground rather than rise vertically and grow 10 to 30cm  long. Blooming time is from May through to August with clusters of flowers in shades of purple-violet. It is an ideal ground cover to use between stepping stones or near to patios and walkways.Creeping thyme is  hardy to -34°C  with good drought tolerance. The seeds of creeping thyme are very fine, much smaller than grass seeds, so it is a good idea to mix the seeds with a filler like sand to avoid dropping 90% of your seed. The best time  sow is in the spring or autumn when the temperature is around 13°C.

Brass buttons (Leptinella squalida) is a relative hardy ground cover that can take light foot traffic.This mat forming plant only grows to about 2″ tall but spreads out indefinitely by rhizomatous runners. The grayish green foliage turns to a beautiful bronze color in the fall.Platt’s Black is a very popular hybrid that has unusual, purplish black foliage. Small, ¼” golden yellow, button-shaped flowers appear from late spring until mid summer, followed by tiny, inconspicuous fruit.Brass Buttons plants grow and bloom best in full sun, but they will tolerate light to partial shade. Leptinella seeds can be sown directly in the garden during late spring and summer months, up until two months before the first frosts of fall. Seeds will germinate within 2-3 weeks.

The following website provides more information on groundcovers from seeds: https://www.richters.com/show.cgi?page=MagazineRack/Articles/Groundcovers.html

Good Luck!