Winter weed control

Published 12:27 am Sunday, January 30, 2011

This is the time of the year we receive some repetitive calls every year on the same subjects; winter weed control, Irish potatoes, pruning trees, and other calls that seem to come in from numerous citizens. I received several calls this week on winter weed control and a few on preparing for Irish potatoes. So here are some answers to those questions.

Q.When can I plant Irish potatoes?

A.Potato growers should be getting the garden ready. Bury potatoes about four inches below the surface with the eyes looking up in the direction they will be growing. If you have raised beds this is even better. It makes digging potatoes easier and will help keep the new potatoes from rotting if we have a wet spring. If you start planting now this may allow you to harvest them for several weeks and to boil them along with the green peas you planted last month.

Email newsletter signup

Q.How do I control all the weeds in my yard right now?

A.We are fortunate to have a climate where we can grow things year round. The only problem is along with growing vegetables and flowers all year, we also must continue the fight with unwanted weeds. Right now and in the coming weeks we will begin to see a lot of weeds like henbit, chickweed, clover, lawn burweed, wild garlic and wild onions and then seeds of warm season weeds starting to thrive. If you have this problem you have a few options. One is just mow them down. This will help keep them out of view and help keep our yards looking fresh, but the problem still exists. You could just do nothing and they will slowly die with warmer weather after leaving millions of seeds to grow next year. Or you could use a herbicide to provide control.

There are four factors to keep in mind when using herbicides; timing, rate, coverage and activation. Pre-emerge herbicides, such as atrazine or 2,4-D, must be applied prior to weed seed germination. Many seeds will begin to germinate when soil temperatures reach around 58 degrees. Even though it may feel awfully cold right now it doesn’t take but a few sunny days to raise the soil temperature to this level. A post-emerge herbicide is applied right now while weeds are actively present in your yard.

The herbicide label will provide a list of the weed species the active ingredient will control and at what rate. If there are several weed species that you are targeting use a rate that controls the most difficult weed while staying within recommended rates labeled for your specific turf species.

Pre-emergence herbicides work by creating a thin weed control barrier on the soil surface. This barrier must provide complete coverage at a uniform rate to prevent any voids that would allow weed escapes.

For most of you in our area St. Augustine is the predominate grass. If you apply an application of atrazine to your yard in the next few weeks it will help serve as both a pre and post-emergence herbicide. Meaning it should eliminate most current winter weeds and reduce warms weeds from emerging , therefore you should have enhanced weed control for the coming months.

David Carter is director of the Adams County Extension Service. He can be reached at 601-445-8201.