ALABAMA A&M AND AUBURN UNIVERSITIES Home Garden Vegetables IPM-1307 Weed Control Recommendations for 2013 Good weed control may determine to a large extent the a wide range of soil moisture conditions, and very little skill success of your home garden. Weeds compete with the crop is required. Also, mechanical methods may be used as often for soil moisture, sunlight, space, and plant nutrients. They as needed. Mechanical weed control is the most practical compound disease problems and serve as hiding places for approach to weed control in small gardens. The greatest insects. Also, weeds may prevent dusts and sprays from weakness of mechanical methods is the lack of residual control. thoroughly covering your garden plants, resulting in poor pest Mulching. Mulch can be a valuable asset in controlling control. weeds in perennial and long-season crops like asparagus, Weeds can usually be divided into two groups—grasses strawberries, tomatoes, and peppers. Six inches of pine straw and broadleaf weeds. Grasses are multistemmed plants with or 3 inches of leaves or well-decomposed sawdust will help fibrous root systems. Once grasses become established, they suppress most weed problems. Mulch also helps keep the soil are difficult to control without injuring the vegetable crops. surface cool and cuts down the evaporation of soil moisture. Grasses are very competitive in gardens and make harvesting Many gardeners clean-cultivate and mulch heavily to control difficult. Many broadleaf weeds grow upright and have taproot weeds later in the season in crops like tomatoes, peppers, systems which make them easier to pull than grasses; therefore, and okra because late cultivation could damage these large, the vegetables receive less injury. spreading plants. Preventive Weed Control. New weed seed may be brought Mulch gradually decomposes during the season, and into a garden on plows or tillers that have been used in weedy sometimes this may cause plants to develop a slightly yellow areas. Poultry litter, compost and manures sometimes contain cast. A light application of about 1 pint of ammonium nitrate troublesome weed seed. Weedy hay used for mulch may bring per 100 feet of row will usually correct this problem. Additional an number of new weed problems. Occasionally, home-saved mulch may be added as needed when the older material settles vegetable seed may also include some weed seed. or decomposes. At the end of the season, the mulch can be Most of the weed problems in the garden are homegrown turned under or incorporated to add organic matter to the soil. problems. That is, they come from weed seed produced in Chemical Weed Control. There are very few herbicides the garden in years past. Season-long weed control to prevent labeled and available for use in the home garden. These weeds from reseeding should be a basic part of any weed herbicides are discussed in the following table. These control program. Controlling weeds by preventing them from herbicides control only annual grasses and, in some cases, making a seed crop may be a long-term process, but in the end small-seeded broadleaf weeds. They usually do not give it is the only sure way to control this problem. acceptable control of most broadleaf weeds. Mechanical Weed Control. Historically, gardeners You may choose to use a herbicide to control grasses in have used hoeing, plowing, hand-pulling, and mulching to the garden. However, you must be prepared to rely on hoeing, control weeds. Mechanical control methods used on a regular plowing, hand-pulling, and/or mulching to control broadleaf and continual basis provide good weed control for serious weeds that escape chemical treatment. gardeners. This usually means frequent light cultivations with Summary. Because of the high variability among vegetable a plow and hoe to destroy weeds in the two- to four-leaf stage. crops, weed problems, cultural practices, and soil types, no A few minutes spent destroying the flush of weeds that usually step-by-step weed control system has been devised. Using a emerge after every rain is much more effective than hours or combination of herbicide treatment, mechanical weed control, days spent trying to destroy established weeds. and mulching—capitalizing on the best features of each of Many gardeners have too large a garden to control weeds in these practices—is the best approach to weed control in the the time available for that ARCHIVEtask. A few well-managed rows may home garden. produce greater yields of higher-quality vegetables than a larger Precautions. Always follow the manufacturer’s directions area tended in a slipshod manner. printed on the label for handling and use. Store and discard Mechanical weed control gives immediate results. There containers properly. are no problems of uniform application, drift, and residues as with chemicals. Weeds may be controlled mechanically under www.aces.edu 2 • Alabama Cooperative Extension System Home Garden Vegetables Weed Control Chemical Name And Trade Name Amount Per Crops (rate per acre) 1000 Sq. Ft. Comments PREEMERGENCE Asparagus (established) trifluralin Apply to weed-free soil anytime from 6 Broccoli (transplants) PREEN GARDEN Coarse and medium weeks before up to planting. If bedded Brussels sprouts WEED soils: 0.75-1.0 lb. culture is used, apply after beds are formed. (transplants) Trifluralin must be thoroughly incorporated PREVENTER Fine soils: 1.5 lb. into the soil to a depth of 1 to 1.5 inches. Cabbage (transplants) 1.47 % granules To achieve this depth, set incorporating Cauliflower (transplants) (33-65 lb.) equipment to cut 2 to 3 inches deep. Celery (transplants) or Incorporate immediately after application Collards TREFLAN 4EC Coarse and medium for best results. However, incorporation may English peas (1-1.5 pt.) soils: 0.75 T. be delayed up to 8 hours after application. Irish potatoes Fine soils: 1.125 T. Controls crabgrass, goosegrass, fall panicum, Kale foxtails, barnyardgrass, signalgrass, seedling johnsongrass, sandbur, Texas panicum, Lima beans annual bluegrass, bromegrass, junglerice, Mustard greens stinkgrass, carpetweed, chickweed, Florida Okra pusley, lambsquarter, pigweed, knotweed, Peppers (transplants) purslane, and henbit. Soup beans Southern peas Tomatoes (transplants) Turnip greens Field corn atrazine Atrazine is a RESTRICTED USE pesticide. Sweet corn AATREX 80 W or Coarse and medium Controls crabgrass, Florida pusley, Florida ATRAZINE 80 W soils: 2T. beggarweed, pigweed, teaweed, annual morningglory, sicklepod. lambsquarter, (2.5 lb.) ragweed, smartweed, and cocklebur. AATREX 4L or Coarse and medium Spray soil surface immediately after planting ATRAZINE 4L soils: 2T. or up to 3 weeks after planting, provided (2 qt.) weeds are no taller than 1.5 inches. DO NOT AATREX 90DF or Coarse and medium plant fall vegetables in areas treated with ATRAZINE 90DF soils: 1.5 T. atrazine. Thoroughly till soil before planting any spring crop other than corn. Must have (2.2 lb.) 0.75 inch of rainfall or irrigation within 5 days after application. Established vegetables corn gluten meal Apply to weed-free soil around established Established herbs PREEN ORGANIC 20 lb. vegetables, herbs, and fruit. These plants Established fruit WEED PREVENTER should be at least 2 to 3 inches tall and have true leaves. Re-treat every 4 to 6 weeks around existing vegetables, herbs, and fruit to maintain a weed-free soil surface. Corn gluten will not control emerged weeds and perennial weeds. Controls crabgrass, foxtail, annual bluegrass, lambsquarters, purslane, and pigweed. DO NOT apply to areas to be ARCHIVEseeded with desirable plants. Home Garden Vegetables: Weed Control Recommendations for 2013 • 3 Home Garden Vegetables Weed Control (cont.) Chemical Name And Trade Name Amount Per Crops (rate per acre) 1000 Sq. Ft. Comments POSTEMERGENCE Asparagus sethoxydim Controls actively growing grass weeds. Cabbage POAST 1.5 Unsatisfactory results may occur if grasses Cantaloupes (1.5 pt.) 1 T. are under moisture stress at time of treatment. Cauliflower Does not control sedges (nutgrass) or + + broadleaf weeds. A repeat application at 1 Collards Crop Oil Concentrate Cucumbers pint per acre to perennial grass re-growth will (2 pt./A) 1.5 T. be necessary for best result. See label for pre- Dry beans harvest interval for different vegetable crops. Eggplants or Under conditions of high temperature and Garlic high humidity, some speckling or spotting Kale GRASS GETTER may be observed on vegetable foliage. A Mustard greens (1.5 pt.) 1 T crop oil concentrate MUST be added to spray Onions + + mix to achieve grass control. Sethoxydim Peppers Crop Oil Concentrate controls crabgrass, barnyardgrass, foxtails, Potatoes (1.5 pt./A) 1 T goosegrass, junglerice, Texas panicum, fall Pumpkin panicum, annual ryegrass, and signalgrass. Squash Johnsongrass and bermudagrass can be Southern peas controlled with repeat treatments. Sweet potatoes Tomatoes Watermelons Home Garden Vegetables: Weed Control prepared by John W. Everest, Professor Emeritus, Crop, Soil and Environmental Sciences, Auburn University. For more information on pesticides, pesticide safety, or submitting samples for analysis, see the following publications in the IPM series: IPM 1293, “Safety.” Safety contact information; worker protection standards; the safe use, handling, and storage of pesticides IPM 1294, “Submitting Samples.” Procedures for submitting samples for diagnosis, analysis, and identification IPM 1295, “General Pesticide Information.” Federal and state restricted use pesticide lists; pesticides and