Spring Is Near Part 2
In my last post I mentioned that crabgrass preemergence herbicides are packaged as a percentage of the active ingredient (ai). When buying these products first check the bag for what herbicide it contains and what is the percentage of the active ingredient.
Generally the product with higher percentage of active ingredient, the smaller the bag will be by weight. The reason for this is that the application amounts are base on a recommended quantity of .25 lbs. of active ingredient per acre. This where it gets somewhat confusing and requires a simple explanation.
One of the more common herbicides formulated for home use is dithiopyr. Dithiopyr is considered both preemergence and postemergence because it will control crabgrass seedling prior to tiller development. Two examples of products sold locally are Sta-green Crab-EX 0.17% ai in a 17 lb. bag and Green Light with Dimension (dithiopyr) 0.25% ai. in a 10 lb. bag. Both products cover 5000 sq. ft.
Why? Sta-green recommends applying the product at 3.4 lb. per 1000 sq. ft thus the 17 lb bag and Green Light recommends applying the product at 2.4 lbs per 1000 sq. ft. thus the 10 lb. bag.The consumer needs to be aware of this information and base their choice on these facts. The most important thing to do when applying herbicides and fertilizer is to know the square footage of your lawn and apply the correct amount that is recommended on the label. By applying ½ the amount in one direction and ½ the amount at 90 degrees will insure complete coverage of your lawn area. The herbicide must be irrigated into the lawn by a ½ ” rainfall or by sprinkler to give good weed control.
I purchased Green Light at Virginia Beach Feed and Seed on 132 N. Witchduck Road near Cleveland Street and would recommend them for their service and knowledge.
Please read and follow the package label.
Apply wisely to protect the Chesapeake Bay.
Tags: active ingredient, Crabgrass, preermergence, rain, temperatures, weather