Troup extension agent: How to control weeds in the garden

Published 12:00 am Friday, May 6, 2016

By Brian Maddy

Contributing columnist

As soil temperatures warm up and gardeners begin to plant their transplants and seed, the issue of how to control weeds often arises. Weeds compete with our vegetables for water, light and nutrients. Weeds also diminish yields. A weed is a plant out of place so how do we control weeds in our garden?

The problem with vegetable gardens and controlling weeds is that we grow plants in small spaces that have different plant characteristics. You can divide plants into two main categories, grasses and broadleaves. Grasses have parallel veins and broadleaves are palmately veined, that is the veins radiate from the stem to the tips of the leaves like the fingers from the palm of your hand.

Herbicides generally control one or the other. Using a pre-emergent herbicide usually doesn’t work in a small garden if you grow corn, a grass and green beans, a broadleaf. If you have large areas to plant and you flag off the areas it might work. You must read the label very carefully. Identifying the weed is the first step in selecting herbicides.

If you use a nonselective herbicide such as Roundup, if both the plants and weeds are up at the same time you run the risk of spraying both and killing the vegetables. Even if you are careful, spray drift may cause damage as well. You can use a shield to protect the plants in the row or you can use a hand rope wick applicator.

A rope wick applicator applies the glyphosate through the rope as it touches the target weeds. The handle is usually filled with a 100 percent solution of 41 percent glyphosate. Be watchful of dripping on the vegetables.

Tilling the soil is the most common method of controlling garden weeds. It uproots the weeds and dries out the roots. The bad part about tilling is that it also brings up buried weed seed and places it in an environment where it may germinate.

Weed seeds can stay dormant for many years in the soil. This is why after each deep cultivation, a flush of weeds appear. They are usually all the same height.

Weeds are much easier to control when they are small and in the “white root” stage. When they are uprooted at this stage the ground heat will whither the “white root.” If you have to pull weeds with both hands, you’ve waited too long.

Controlling weeds in the top two inches of the soil is the best bet. If the weed seed is exhausted in the top 2 inches, weed control is much easier. You may have to pull the occasional escapee. If you deep till, the process will start all over again.

The usual method of controlling weeds after the vegetables are up and growing is using a hoe. The most common hoe is a paddle hoe with a gooseneck for better alignment for the 6 by 4 inch blade.

A warren hoe has a triangular blade, which helps in tight spots and in making planting furrows. The onion hoe has a long and narrow blade, 2 inches wide and 7 inches long.

A scuffle or loop hoe works in both directions and is a favorite of many gardeners. A newer style is the heart hoe, which works much like the scuffle hoe and can rotate in any direction.

Never dig deep with a hoe. They are designed for shallow cultivation. A fiberglass-handled hoe will last for many years, but a wooden handled hoe that is oiled and kept out of the sun will last a long time as well.

Another option is using mulch to control weeds. Placing mulch or compost around the plants will suppress weeds, conserve soil moisture and add organic matter.

Do not use fresh woodchips or sawdust because they will draw the nutrients away from the vegetables. Manufactured products such as the mulch plastics and paper products will warm the soils and suppress weeds.

Many of our large-scale vegetable farms utilize plastic mulch on raised beds. Old newspapers work well if wetted and rocks or bricks are placed on them to prevent them from blowing into a neighbors yard. The purpose of the mulch is to deny weeds sun and to act as a barrier to growth.

Another way is to plant a winter cover crop such as Yuchi clover, crimson clover and/or winter rye. These plants form a natural mulch when mowed in the spring.

If you cultivate just where you plant your vegetables this system will provide weed control into July. Rye also has an allelopathic effect which suppresses weeds.

Remember that by exhausting the weed seed population in the top two inches of the soil is the best solution for weed suppression. Minimizing your tillage will also reduce weed population as well as not letting your weed go to seed.

What’s going on in Extension?

May 12 — MGEV meeting, 7 p.m., Ag Center.

May 13 — Egg Candling Class for all those who sell eggs in Georgia. 10 a.m.–3 p.m. at the Ag Center. No cost. Must pre-register! Only 50 slots available.

May 16, Troup County Association of Beekeepers, 7 PM, Ag Center.

May 17, Troup County Cattleman’s Association, Ag Center. Guest speaker, Seth Hamer, SunSouth, “Drill Calibration.” Meal at 7 p.m.; program begins at 7:30 p.m.

If you have any questions or concerns, stop by or call the Extension office.

Brian Maddy is the ANR Agent for Troup County Extension. The Troup County Extension office is located at 114 Church St. in LaGrange and may be reached at 706-883-1675, Monday–Friday 8 a.m.–noon and 15 p.m.