Killing clover amid groundcover
I replaced grass along 200' x 10'+10' on both sides of a full-sun driveway with groundcover (Pachysandra, Myrtle, Dianthus, Creeping Phlox, Liriope, English Ivy, stonecrop Sedum) and have battled clover for 3 years now. When the clover rose above the Dianthus last year, I lightly misted its leaves with glyphosate hoping to kill it without harming the Dianthus, but I damaged much of the lush two-year old Dianthus, which is recovering very slowly. I have been zipping up the creeping stems and digging out the roots of the clover but this tedium only works with the Dianthus. With the similar creeping stems of Myrtle, it is impossible to distinguish them and the clover is thriving. I have contacted several chemical companies for a clover-specific herbicide with no luck. I sprinkled corn gluten meal this summer but the nitrogen did no harm and possibly helped the clover grow. Do you know of any chemical or physical way to get rid of the clover without harming the other plants?
Hello and thanks for using the Ask an Expert System.
I am afraid that the short answer to your questions is, ”No!” An established clover crop within your existing groundcover is very difficult to control. There are annual and perennial varieties of clover and control measures will depend on which type you have. You will find information on different tyes of clovers and control measures at http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7490.html
Pre-emergent weed killers like corn gluten will only work on preventing seed germination, and they must be applied at the correct time of year. . They will control annual clovers, but not perennial types.
Any broadleaf weed killer will kill your ground cover plants. You might try treating the young and actively growing clover with glyphosate. Spraying or misting will always produce overspray that will damage your groundcovers. However, if you put the glyphosate in an envelope dauber (the tube with a sponge tip used for licking envelopes), and then just brush the tops of the clover plants. You should get some measure of control without overspray.
If the clover is heavily established you will have to continue to treat indefinitely. Your best bet may be to pot up as many of the groundcover plants as you can then treat the whole area with glyphosate and then replant your potted groundcover plants after waiting a week. You might still have to use a pre-emergent herbicide if there are seeds left in the ground. If you do elect to apply any herbicide be sure to read the label carefully and follow all instructions.
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