Weeds: The Endless Burden
By T. Jeff Williams
A weed is just an otherwise nice plant growing in the wrong place at the wrong time, namely in our garden. Weeds crowd out desirable plants, rob the soil of essential nutrients and water, and look unsightly on our lawns and gardens. As a result, gardening is often more about weeding than actually growing our favorite flowers or vegetables. Weeding is endless!
Weeds in general can be categorized as either annuals (live just one year) or perennials (live several years), and whether they are broadleaf or narrowleaf. Dandelion is a typical broadleaf weed and crabgrass is narrowleaf.
The three main methods used to rid our gardens of weeds are by:
- Chemicals
- Hand tools
- Mulches
Chemical Control
When weeds have taken over a large part of our yard or garden and hand weeding is getting us nowhere, then chemical control is a swift and effective solution. This primarily involves the use of nonselective or selective herbicides.
Selective herbicides target specific weeds while leaving adjoining plants unaffected. Notable among these is Weed-B-Gon, which kills broadleaf weeds in the lawn, such as dandelions, without affecting most turf grasses.
Nonselective herbicides kill all plants they contact. These herbicides include OSH's Easy Gone Weed and Grass Killer and Roundup. Both are systemic herbicides that kill the weed to its roots without affecting the surrounding soil. Both contain the chemical glysophate, which disrupts a plant's protein production.
Herbicides may be liquid or granular. Liquid herbicides can be in handy spray-ready containers or concentrate, which requires mixing exact portions with water before application. Granular herbicides don't require any mixing and are easily distributed with broadcast spreaders. These herbicides are generally selective and commonly used to combat broadleaf weeds in lawns.
Targeted weeds normally begin to wither and die in about a week or less, but some weeds are more resistant than others and may require several treatments. If using nonselective herbicides near valued plants, protect them with a makeshift cardboard shield while spraying. Using a herbicide that comes in small spray bottles will also allow you to shoot it directly on one weed at a time, minimizing risk to adjoining plants. You will find a variety of these sprayers in the OSH gardening section.
One- or two-gallon garden sprayers are the best choice for delivering concentrate mixes to heavily infested areas. It's advisable, however, to use that sprayer only for herbicides-and kept clearly marked. Otherwise, if not thoroughly rinsed each time, some trace herbicides may damage desired plants.
There is also a soil sterilizer, Easy Gone Total Vegetation Killer, which will prevent anything from growing in the treated area for about one year. It can be used under trees and other large plants to prevent weeds from hindering desired growth.
Another chemical attack is launched with preemergent herbicides, which kill new shoots as soon as they sprout. Two examples of this at your local OSH are Preen and Amaze. Preen are pellets simply shaken from the container. Amaze is spread with a hand-held or wheeled spreader. For lawns, an effective preemergent for crabgrass is Scott's Crabgrass Preventer. It does not kill crabgrass on contact, but instead catches the seeds as soon as they sprout in spring.
Mechanical Control
The tried and true mechanical weed killer is a determined gardener with a hoe in hand. Chopping weeds on a regular basis is good exercise and good for your garden. The best approach to weeding with tools is to turn the ground over with a shovel as soon as it's ready in the spring and pull all the weeds as you go. Rake the ground level and if you have time wait until the new crop of weeds pops up and pull them from the soft earth.
Chopping weeds below the surface will kill many types, but others will bounce right back, including those with deep tap roots like dandelion, oxalis and mallow. Even so, regularly cutting them back prevents weeds from shading out other plants, minimizes areas for snails and slugs to hide, and reduces the loss of nutrients and water to the weeds.
The standard garden tools are well known, such as hoes, shovels, picks for hard ground, and a variety of garden trowels. There are specialty hoes, such as the scuffle/weeding hoe to cut weeds at the surface, and triangular-shaped hoes for working in tight places, not to mention round-tip and square-tip shovels. All should be part of the dedicated gardener's arsenal.
Mulch Control
Mulching is an effective weed prevention method that is also highly beneficial to the garden. Mulch is traditionally a layer of organic material spread around and under vegetable and flower plants. It may be straw, compost, bark, or even old newspapers.
Even a thin layer of mulch will significantly reduce the amount of soil moisture lost to evaporation. Thick mulch layers, at least four inches deep, will also prevent sunlight from reaching the ground, thus stopping most weeds from sprouting. And when the growing season is done, just turn the mulch into the soil, an excellent way to break up the clay soil so widespread in California.
Mulch left in the garden during winter will protect the soil from heavy rains that can erode the ground. You can find a variety of mulches bagged and ready to go in the OSH garden section.
While organic much is the long-time standard, another form of mulching with landscape fabric has gained widespread popularity. This polyester material allows water to penetrate, but prevents weeds from growing through. It comes in various widths and can be easily cut with scissors to fit in any area. Be sure to peg it down, particularly along the edges, with special metal spikes. Once in place the fabric can be covered with decorative bark or colorful gravel. It is perfect for the underlayment on gravel walkways through a garden.
Black plastic sheeting is another form of mulch. Cover an area with this and nothing will germinate under it. But you can spread it on a planting area, cut a hole for each vegetable or flower to be transplanted, and you will have no weeding problem. Watering has to be set up under the plastic, such as with a drip system. Ultraviolet rays will eventually cause the plastic to disintegrate, but it will last for one growing season.
If you want to kill off all growth in a certain area, cover it with black plastic and then cover the plastic with bark or gravel to protect it from the sun.
Organic Control
Weeds can be controlled naturally to a certain extent by planting vegetables that grow quickly and crowd out weeds. Corn, tomatoes, cucumbers, melons and others do this, but it's far from perfect.
Corn gluten meal, which is derived from corn processing, is an organic weed control. It is most effective as a preemergent weed preventer when used on lawns. It eventually breaks down into pure nitrogen, an added benefit for the lawn.
In summary, we will never totally defeat weeds, and we shouldn't, for they are part of the whole ecology. But with a little effort we can keep them under control, keep our gardens beautiful and our minds at rest.