Weeds and Plants Placerville CA
El Cajon, CA
Redwood City, CA
Weeds and Plants
Ever since the first plant was grown for food or beauty, the first gardener cursed neighboring plants -- weeds. A weed is any plant in the wrong place. Tomato seedlings popping up in the garden from last year's fallen fruit might be considered weeds. Goldenrod, often considered a weed in America, stands proudly in British flower gardens. We gardeners have to come to terms with weeds -- understanding the harm they do, as well as recognizing their benefits -- then keep them sufficiently in check.
Weeds can choke out garden plants, starving them for water, minerals and light, if the weeds are tall and the garden plants are small. But competition is a matter of degree. A rampant clump of smartweed will choke out young carrots, but how much damage is a little purslane growing at the foot of cornstalks going to do?
Certain weeds also harbor pests, or secrete chemicals that are harmful to garden plants into the soil. Potato bugs, for example, get their start for the season on weedy horse nettle before they home in on your potatoes. And if you've ever noticed other plants growing poorly near sunflowers, part of the reason may be the growth-inhibiting chemical that rain leaches from sunflower hulls. (Tall sunflowers, of course, also are heavy feeders and cast shade.)
But weeds are not all bad. Weeds thankfully move in to clothe and protect bare soil from pounding rain and hot sun wherever the earth's green mantle has been stripped away. Weeds also add diversity to a planting, helping to cycle soil nutrients as well as sometimes offering food and shelter to beneficial insects. And weeds can tell you something about your soil: For example, yarrow indicates a dry soil, clover tells of a soil low in nitrogen, and sorrel an acidic soil. So a little weed growth in the garden can be beneficial, besides being unavoidable.
It is sometimes necessary to get down on your hands and knees to pull some stubborn low-lying weeds - such as the patch of creeping charlie shown here - without disturbing the mulch.
Soon after cursing weeds, those first gardeners came up with ways of dealing with them. Today's hoe is probably not much different from the first tools used to kill weeds. The principle is simple: Keep slicing the tops off weeds so that they starve to death from lack of sun-charged energy.
The best of today's hoes are the collinear hoe and the Winged Weeder, whose blades are sharp and remain parallel to the ground as you work. Use these hoes while walking backwards, sliding the blade back and forth just beneath the surface of the soil as if you were sponge-mopping your kitchen floor. Hoeing is a pleasant activity if not neglected so long that weeds grow beyond the seedling stage.
Some gardeners may think: Enough with this primitive stuff. I'll just use weedkiller herbicide to get rid of weeds easily and thoroughly. Newer, less toxic (to humans) herbicides have been developed recently. Some contain corn gluten, which kills sprouting seeds, so they are useful for keeping new weeds from sprouting in established plantings. Other herbicides contain special soaps, vinegar or other natural products, all of which have various effects on different weeds and kill only leaves, not roots, so they must be sprayed repeatedly. I've concocted a particularly effective homemade spray by adding a tablespoon of salad oil and two tablespoons of liquid dish detergent to a gallon of 5 percent white vinegar. Regularly spraying a narrow band at the garden's edges keeps weeds from creeping in. This spray is also useful against weeds that pop up between paving stones or bricks on paths and patios.
Don't be too quick to take the herbicide approach to weed control. Before applying any herbicide, you must make sure that it will be effective on the particular weeds you want to kill and, in the case of synthetic (chemical) herbicides, that no harmful residue will remain. For effectiveness, you must apply the right concentration of material at the right time, perhaps even don protective clothing as you work. When you are finished, you must clean the sprayer thoroughly and, with certain herbicides, never again use the sprayer for anything else. Continued use of any single herbicide may just change which weeds cause problems, since many herbicides target specific weeds, and other weeds will be resistant.
Might not hoeing be simpler and safer? If you have an aversion to hand-hoeing, you could use a rototiller or a push hoe, both of which accomplish the same thing as a hand hoe. As with the hand hoe, frequent but shallow cultivation is ideal. The shallower the cultivation, the less likely you are to chop up the worms in your soil a vital resource to gardeners.
Alternatives to Hoeing & Spraying
Mulches are yet another way to keep weeds in check. The most commonly used synthetic mulch is plastic film, usually black plastic. Plastic film is easy to lay down, effectively suppresses weeds and hastens warming of the soil in spring. Experiments with other variously colored plastic films have shown effects on both pests and plant growth. A reflective plastic mulch, for example, keeps aphids at bay.
A big disadvantage of plastics is that they are ugly, so they need to be covered in ornamental plantings. The bark or wood chips usually used as covering eventually get invaded by weeds. In annual plantings, such as vegetable gardens, the plastic eventually needs to be disposed of and also occasionally causes problems due to poor soil aeration. Plastic adds nothing to the soil as far as nutrients or humus.
Paper mulches sidestep many of the drawbacks of plastic mulches. Use recycled paper occasionally manufactured specifically as mulch, gray rosin paper, kraft paper, or any plain paper, such as newspaper (black-and-white pages only). Paper mulches are easy to lay down and eventually decompose, so they do not cause a disposal problem. Paper adds little to the soil in terms of humus or nutrients.
Bulky organic materials such as leaves, grass clippings and wood chips make excellent mulch and are often free. Lay them on top of the ground a couple of inches deep, but not right up against the stems of young plants, or they may cause stem rot. Organic mulches need regular replenishment, but as they decompose, these mulches enrich the soil with humus and nutrients.
Organic mulches are insulators, so they delay soil warming in the spring, putting off how soon you can get plants or seeds into the ground. Avoid this problem by temporarily pulling back the mulch in late winter, then putting it back in place after the soil has thoroughly warmed in spring. No need to hasten soil warming with established plantings, such as perennial flowers and shrubs. Because they insulate, organic mulches have the benefit of protecting roots from excessive heat in hot summers, and of delaying soil cooling in autumn, allowing roots and soil organisms to remain active longer.
To Turn or Not to Turn
Years ago, besides making the usual direct attacks on weeds, I began to consider how my gardening practices were indirectly influencing weed growth. For instance, whether or not the soil is turned over each year in preparation for planting has a dramatic effect on weed growth. This is because myriad weed seeds are lying dormant in the soil, just waiting to be awakened by light and air. Although hand-digging, rototilling and plowing bury existing growth, these practices also inadvertently so new weeds, as they bring seeds to the surface. So I stopped turning over my soil.
Soils are tilled or turned to aerate them and to bury old plants and weeds. Designating permanent areas for walking and permanent areas for planting beds and paths in my vegetable gardens, and beds with stepping stones in my flower beds bypassed the problem of poor soil aeration that tilling was meant to solve. This clustering of plants further reduced weed problems by creating so much shade in planted areas that weeds had trouble developing there. Because I wasn't tilling, when it was time to clear away spent garden plants or large weeds, I did so just by pulling them out by hand, roots and all. A quick twist of the plant tops severs the plant from its fine roots, which just stay in the soil to enrich it. I coax tap-rooted plants or weeds out of the ground by sliding a trowel or shovel next to the taproot and levering up as I pull. Small weeds are done in with the aforementioned Winged Weeder or collinear hoe.
I also incorporated mulches into my weedless gardening system, making sure that any mulches I use are weed free. My vegetable beds get blanketed with compost, the paths with wood chips, and the flower beds with leaf mold (rotted leaves).
Finally, I considered my watering. A sprinkler blankets a whole garden with moisture, promoting weed growth and wasting water in paths and the spaces between large plants. So any part of the garden that gets regular watering is now drip irrigated. Via an inexpensive (and easily automated!) system of tubes and special emitters, drip irrigation pinpoints the water supply right to the roots of garden plants.
Neither my weedless gardening system nor any of the other individual techniques mentioned will permanently eradicate weeds. The goal, rather, is to keep weeds in check, to make truce rather than war with them. Maintaining this truce requires constant attention rather than massive effort. Shakespeare's advice is as true today as it was when it was written 400 years ago: Now tis the spring, and weeds are shallow-rooted; Suffer (neglect) them now and they'll grow the garden (King Henry VI). For the past two decades, my weeding has been reduced to a few pleasant minutes a week.
Lee Reich, Ph.D., author of Weedless Gardening (Workman Publishing, 2001), worked in agricultural research for the U.S. Department of Agriculture and for Cornell University, and comes to terms with weeds in his gardens in New Paltz, N.Y.