Spring weed control update
Categories: Lawn Care Pesticide and fertilizer application Seasonal maintenance Weeds
Unless we get another freeze, the window for applying pre-emergence crabgrass control has effectively closed as crabgrass is germinating all over Payne County this week. If being crabgrass free is really important to you, you still have one option and that is to look for a product that contains dithiopyr. The most common trade name for this pre-emergent product is Dimension ® herbicide. When used correctly, this pre-emergent product will also provide good post-emergent control of crabgrass for the next three weeks or so (while it is still young).
As with all pesticides, please read the label and follow the directions for a proper and safe application. One of my roles as an Extension Educator is to help citizens of Payne County with their garden and landscape problems. Unfortunately, a significant number of the problems I see are a result of a careless disregard for using these products properly. I’ll freely admit that the labels can sometimes be a bit overwhelming, but I’m happy to help you decipher them if you will give me a call or send me an email.
As a reminder, pre-emergent products form a vapor barrier near the soil surface and kills the plant as it emerges and attempts to grow through the barrier. If the plant is already established, the other products will simply not work-no matter the rate. This also explains why these products “break down”, i.e. don’t work when the soil is disturbed through tillage, animal activity, etc.
A related subject, and one that can’t be talked about too often, is the need to exercise care when using broadleaf weed killers this time of year. These products are troublesome right now because of the “perfect storm” that exists: it’s windy, plants are just emerging or putting on new leaves and are especially sensitive to herbicides now, and the maturing weeds are more resistant to the products. The best advice I can offer if you are aggravated by a flush of spring weed growth is to mow often enough that the weeds don’t set seed and to mark your calendar RIGHT NOW for mid-August to contact me about how to control these weeds next year!
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