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Treflan for Vegetable Gardens

Image by, courtesy of Gabriel K

Treflan is a the brand name of trifluralin, a pre-emergent herbicide, meaning that it is applied to kill weeds before crops appear. As with all herbicides, Treflan is a poison and should be applied with careful attention to the directions on the manufacturer’s label.

Trifluralin Brands

All herbicide labels are required by law to contain the common, chemical name of the herbicide that kills weeds in addition to the trade or brand name. Treflan is not the only herbicide containing trifluralin. Besides Treflan, trade names of herbicides containing trifluralin include Crisalin, Elancolan, Flurene SE, Ipersan, L-36352, M.T.F., Su Seguro Carpidor, TR-10, Trefanocide, Treficon, Tri-4, Triflurilina 600, Triflurex Trim and Trust.

Another brand that uses the chemical trifluralin to kill weeds will work just as well as Treflan, though the directions on the label may vary. They are all pre-emergent herbicides useful for vegetable gardens, the same as Treflan; the active ingredient in each, trifluralin, works the same way.


Treflan comes in granular and liquid forms. The agricultural extension service of the University of Maryland recommends punching holes in the lid of a jar to apply the granular form of Treflan. Use 11 to 16 tablespoons of 5 percent granular Treflan per 1,000 square feet of garden.

Use a sprinkling can to apply liquid Treflan. For each 1,000 square feet of garden, use 2 to 3 level teaspoons of liquid Treflan that contains 4 pounds of herbicide per gallon. Apply half while walking in one direction and the other half while walking in the opposite direction.

No single herbicide will control weeds in all vegetable crops. If you apply too little, some parts of your garden will have weeds; if you apply too much, you can damage your vegetables.

After Applying

When you finish applying Treflan, thoroughly mix the top two to three inches of soil. Use a rotary cultivator for best results. If you don’t have one, irrigate the soil ¼ to ½ inch deep. Plant vegetables any time up to a month after you apply Treflan.

Appropriate Vegetables

Apply Treflan before you plant or transplant these vegetables: dry beans, guar beans, mung beans, snap beans, lima beans, broccoli, Brussels sprouts, cabbage, cauliflower, carrots, collards, kale, mustard greens, okra, peanuts, English peas, Southern peas, sunflowers. For tomatoes or peppers, use with transplants only.


Store Treflan in the original container. Do not store with food, drugs or clothing. Do not freeze or store near heat or flame. Teflon is poisonous. If you swallow it, do not induce vomiting. Drink a large quantity of water mixed with 6 to 8 heaping teaspoons of activated charcoal. See a physician immediately. Do not spray with winds greater than 15 miles an hour or that are gusting. If Teflan contaminates water, it can kill fish. Do not dispose of it in water systems.

For specific information about using Treflan on individual vegetables and application after planting, check the detailed product label posted by the manufacturer, Dow Agrosciences, at

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