Monday, February 6, 2017

Proactive Weed Control

Horticulture Hotline 02/06/17
By Bill Lamson-Scribner

The soil temperature indicates that it is just about time to apply preemergent products to your beds and turf. Valentine’s Day and the running of the Daytona 500 are just around the corner. The time to apply the magical weed preventer is coming up fast, and this year, since our winter has been pretty mild and the ground has been insulated with moisture,
the time might come a little early.

Depending on which Phd doctor you believe, crabgrass germinates when the soil temperature (3 inches deep) stays above 55 degrees (some people say 57 degrees), for 3 straight days provided adequate moisture in the soil. Now some doctors say remains 57 degrees or above for 24 hours at a depth of 3 inches with adequate moisture.  If you are not in to monitoring the soil temperature, Valentine’s Day or the running of the Daytona 500 should work for you. Spreading a preemergent product now could save hours of spot spraying later.

The turf areas as well as the landscape bed areas will greatly benefit from the use of preemerge products. Not only will the yard look better, but your plants will not have to compete with the weeds for sun, nutrients, and water. If you are controlling weeds with preemergent products, there are less weeds there for you to spray or pull, saving you time. There is also less stress on you trying to find time to control the weeds in your yard later once the weeds have emerged. Control them now with a preemergent control product!

For those new readers of the Horticulture Hotline, preemergent control products kill weeds as they germinate.  The weeds never come up and you never have to worry about them.  Crabgrass, goosegrass, barnyardgrass, crowfootgrass, dallisgrass (seedling), foxtail, annual bluegrass, smutgrass, barley, kikuyugrass, wild oats, bittercress, carpetweed, chickweed, Carolina geranium, henbit, knotweed, lespedeza, marestail, black medic, mustard, oxalis, pineappleweed, pigweed, redroot, parsley-piert, purslane, rocket, shephardspurse, speedwell, spurge, and woodsorrel are examples of weeds controlled by preemergent products.  Small seeded annual weeds are controlled by preemergent products.

Read the label of the specific product that you are using to get an exact list of weeds that the manufacturer has tested and shown to control. Preemergent products applied now do not control winter annual weeds that are already up like annual blue grass. To control annual bluegrass, you would have used a preemergent in August and again in October (this could vary with products and rates).

Clover, Florida Betony, Nutsedge and Dollar weed are not controlled by preemergent control products.  These are perennial weeds. Weed Free Zone is a liquid that will do a good job on controlling many of your broadleaf weeds. The Nutsedge will require a different product and is most likely not visible right now.  It is important to control these weeds now before they go into their reproductive stage.  A weed in its reproductive stage is harder to control than a weed in its vegetative stage. By controlling the weed now you avoid having to deal with more weed seeds next year.

It is very noticeable when you ride through the Lowcountry which homeowners and which businesses used preemergent products last fall at the correct time. One business or home lawn will be nice and brown and dormant without a spec of green in sight. Right next to it will be brown turf mixed with green weeds. Again, it is very important to control those weeds now before they begin to flower.

Always read, understand and follow product label. The product label is a Federal Law.