Now is the time, this year, to put down weed killerPublished 10:20am Monday, May 7, 2012
Usually the best time to put down pre-emergence weed killer for crabgrass is late May here in Otter Tail County.
Since we went directly from February to April this year, do it now.
The soil is warm enough that the daffodils are just starting to bloom, the prime time for the first application.
Do the second one when the lilac buds are just showing color. If you already see crabgrass seedlings, it’s too late for most pre-emergence treatments.
The exception is the weed killer chemical Dithiopyr, trade name Dimension. It will control seedling crabgrass plants up until the two or three true leaf stage.
Bunkey gets down on his belly to be able to see these small sprouts, and unless, you are very agile, so will you.
Now to creeping Charlie. You did treat it last fall didn’t you? And it is still there?
If it is in a very shady spot, Charlie may be the only ground cover you can grow there. If you can and feel comfortable with it, you can remove some of the lower branches of the suspect trees to get more light into the area.
You still need to kill Charlie before you re-seed. Hit it while in full bloom with an herbicide. The active ingredient you need to look for is triclopyr.
Since we have had only some of the rain we need this spring, your lawn may be a bit drought stressed. That being the case, be sure to water before and after you spray for broadleaf weeds in your lawn.
The grass in a dry lawn can be killed along with the weeds if your lawn hasn’t had at least an inch of rain a week, and not just this week.
If you enjoy mowing your lawn twice a week, now is also the time for a very light application of nitrogen.
If possible, at least half the fertilizer should have “slow release” nitrogen. If you really pour the fertilizer on now, you will get a full, lush stand of grass.
It will all go to the blades, and very little to the roots.
The roots will be weakened and stressed and less able to supply shoots with the needed nutrients and proper growth.
This sets up the plant to be even more vulnerable to injury from mid-summer heat and drought stresses.
Mow the grass short the first mowing then set your blade to two and one-half to three inches for most of the rest of the season.
Taller grass shades out the weed seeds and the grass’ roots. No, you won’t be mowing more often. It takes the grass blade longer to grow from two to three inches than from one to one and one-half inches.
Taller grass is much more fun to run barefooted in or to do whatever else you may do in the grass.
Bev Johnson is a master gardener for Otter Tail County.