The appeal of toxic herbicides is powerful when you're faced with a garden rapidly dominated by fast-growing weeds. A feeling of desperation, and a lack of knowledge about alternative techniques and tools, are at least two of the reasons some gardeners resort to chemical weed killers. For 21 years I've made my living providing nontoxic weed (and pest) control to suburban customers in the Sacramento Valley of California. My message here is that you can retain your sanity without relying upon herbicides -- or straining your back.
There are two kinds of weed control: preemergence and postemergence. Preemergence weed control methods include the many various techniques that prevent weed seeds from germinating or becoming established in the first place. But my focus here is postemergence weed control: the tools and techniques useful for eliminating and managing existing weeds. Below is a listing of the most troublesome weeds I encounter and the methods I use to control them.
I use only these four simple tools to deal with existing weeds. The least toxic or least intrusive is described first.
Weed Pullers. Although this category does include some of the goofy tools advertised on late-night television, these specialized diggers can work quite well. The basic design is a mechanical weeder that's attached to a long handle so you don't have to kneel or bend over. Sharp tines or prongs, operated by a foot pedal or hand crank, grip the weed and yank it out of the ground with a pulling or twisting motion. You may have to do some experimenting to find a model you like; look for one that removes the greatest amount of root system and the least amount of the surrounding soil.
Long-handled Hoes. Traditional garden hoes with updated design refinements make weeding easier while minimally disturbing the soil. Soil should be moist whenever you are hoeing or pulling weeds.
The collinear hoe features a very sharp rectangular blade and angled handle and is used to cut off small weeds with little effect on the soil.
Push-pull hoes come in a wide variety with descriptive names such as swan neck, oscillating and glide-and-groom hoes and winged weeders. All are intended for use just below the soil surface, cutting off weeds with less effort than traditional garden hoes. Best in sandy soil.
Warren hoes have a triangular shape and allow use close to young seedlings. They also can be dragged through the soil to create a furrow for planting seeds.
Eye or grub hoes are best for heavy-duty digging and cultivating. They have large, heavy blades but usually have a very long handle to provide superior leverage.
Multi-tined weeders are similar to hoes, but the blade is replaced by three to five small tines. These dig lightly through the soil around desirable plants, uprooting weeds. Some models allow you to remove several tines so you can get into tight areas.
Wheel hoes look somewhat like the old horse-pulled plows, but they require some muscle power. Most brands have a variety of attachments for cultivation.
Flame Weeders. "Flamers" do an excellent job of weeding along fences, in pavement cracks and even in turf, and as edging tools, too. All types burn propane from refillable tanks that you fasten to a backpack or sling over your shoulder.
Most flame weeders on the market are the same ones used by fire fighters to set backfires. The flame is about two inches in diameter, too big for a landscape or garden. More practical is the Spot Singafier. It produces a small, easily controlled flame about 1/2 inch in diameter, so is more energy efficient. It costs $205 and is available mail order.
It isn't necessary to completely burn a weed to kill it. In fact, too much heat may actually stimulate roots and produce more top growth. Pass the flame over the weed for three seconds. This will heat the sap, bursting the cell walls. Leaves appear immediately discolored, turning a dull green. They might not actually look dead for a day or two.
Although heat is nonselective, flaming is effective in lawns because grass plants have evolved to withstand fire. They may look scorched, but their growing points are protected from the flame and will quickly recover without any sign of damage.
Natural Herbicides. This is the time when the natural inclination is to spray something, and for those of you in this situation, I do have a suggestion: Safer's SuperFast. It's made from soap and is considered a least toxic pest control product. Weeds wither within a few minutes (though perennial weeds will require repeat applications).
Here are a dozen of the most vexing weeds I normally confront. Annual weeds complete their life cycles in one growing season. They create the most seeds, and don't regrow if top growth is killed. Perennial weeds set fewer seeds, but sustain and propagate themselves other ways, with creeping stolons, rhizomes, bulbs or other plant parts. More often than not, eliminating them from your garden calls for repeat treatments.
Bermuda Grass (Cynodon dactylon)
Control: Cultivation, flaming.
Common Dandelion (Taraxacum officinale)
Control: Long-handled mechanical weeder.
Field Bindweed (Convolvulus arvensis)
Control: Cultivation of young shoots, flaming.
Yellow Nutsedge (Cyperus esculentus)
Control: Cultivation prior to formation of five true leaves.
Broadleaf Plantain (Plantago major)
Control: Long-handled mechanical weeder, flaming, soap herbicide.
Curly Dock (Rumex crispus)
Control: Long-handled mechanical weeder.
Dallisgrass (Paspalum dilatatum)
Johnsongrass (Sorghum halepense)
Control: Long-handled mechanical weeder, hand weeding (be sure to remove roots).
Crabgrass (Digitaria sp.)
Prostrate Spurge (Euphorbia supina)
Control: Flaming, cultivation, hand weeding, soap herbicide.
Common Purslane (Portulaca oleracea)
Control: Flaming, cultivation, soap herbicide.
Redroot Pigweed (Amaranthus retroflexus)
Control: Cultivation, soap herbicide.
Article published on June 23, 2008.