QUESTION: Can you help identify the bright green patches that are in our yard? Is it a grass or a weed? Also, do you have any ideas for getting rid of it?
ANSWER: It’s almost impossible to do a positive grass ID from a photo, but it looks like poa trivialis, or roughstalk bluegrass. If so, it has thinner blades than fescue and a softer feel. This is a perennial grass that can come in grass seed, dropped by birds, or be carried on lawn equipment from one yard to another. Since it’s a perennial, and a true grass, it takes a grass herbicide to control it. You can spot-treat it any time now and overseed those spots with turf-type fescue. The grass herbicide will also kill any good grass you get it on, but you can reseed the fescue in seven days.
QUESTION: My grass looked great until the heat hit in mid-July. Now it looks pretty rough, and lots of weeds have crept in. I know fall is the time to reseed, but can you refresh my memory on the process and the timing?
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ANSWER: You were not alone. I’ve received a number of emails about repairing heat- and drought-damaged lawns. Here’s the process I like: Right away, mow it low and rent a good core aerator. If your soil is dry, water it good for a day or two before using the aerator. Run it over your lawn two to three times in different directions. When you’re finished, you can broadcast your seed and follow it with an application of a starter fertilizer. All three things can be done the same day or at least the same weekend.
If you’re able to water, do it lightly once a day for seven days. By then your seed should be popping up and you can switch to watering longer, but only every three to four days. By the first of October, your new grass should be looking good. Unfortunately, this process will also stimulate the winter weeds that could be trouble next spring. If so, you should be prepared to spot-treat them with a broadleaf herbicide around Halloween. Those weeds will be easy to control while they are young. Lastly, in mid-November, you can treat your lawn with an application of a winterizer fertilizer.
QUESTION: Is it OK to prune boxwood now?
ANSWER: As with most non-blooming evergreens, the best time to prune them is in late February or early March, before they make their new growth. If you prune them now, they will put on another flush of growth that may not harden off before winter. Light trimming of unsightly shoots would be fine, but any serious pruning should wait until late winter.
QUESTION: Wild grape vines are growing over many of my trees and shrubs. I pull down what I can reach and cut through the vines close to the ground on my property. However, I cannot destroy the roots and they keep coming back. Any suggestions?
ANSWER: The best way to kill the roots is to cut the main stem about 6 inches from the ground and immediately paint glyphosate onto the cut stump. The cambium, the growth cells right under the bark, will pick up the herbicide and translocate it to the roots. Now is the perfect time to do it. The vines are starting to store food for winter, so they are ready to move the herbicide deep into their roots.
Richard Nunnally is a freelance writer and is retired from Virginia Cooperative Extension. You can reach him at rtdgarden@gmail.com.