SHERRY'S GREENHOUSE - BEST WEED KILLER?
I am doing a science project at my school on the best weed killers. Can
you give me any help?
The best weed killer is the gardener--no sprays. I don't agree with general spraying in gardens (even organically based types), as they also usually kill beneficial insects. Pouring boiling water on plants will kill them, but it also kills useful organisms that live in the soil below.
Weeds should be pulled before they go to seed. They can then be placed in the compost pile to make humus for the garden.
Another way of controlling weeds safely is blocking their light. Plants need light to make food and grow. In some areas of my garden (and under the greenhouse floor), I have placed weed barrier cloth. It permits water to pass through (unlike black plastic) while blocking light and weed penetration. Patrick A. of Alberta, Canada adds this: "I agree that [weed barrier cloth] is useful for a wide variety of weeds , but it is worse than useless for quack grass (couch grass). The grass forces its way through the cloth and ends up in a right old mess. I speak from bitter experience!"
Planting your garden so that desirable plants are close enough to shade out weeds is another way of blocking light. This should be done in conjunction with a heavy composted mulch. The mulch will have the added benefit of fertilizing your plants.
A heavy mulch can be used. Any weeds that do grow can then easily be pulled. Use mulch and avoid disturbing the soil any more than necessary (which brings weed seeds up into the light where they will sprout and grow).
Another weed control method involves shallow tilling (only about 4 inches deep) to purposely expose weeds which are allow to grow just until big enough to be pulled. This is repeated a couple of times at the beginning of planting time each year.
Also, don't water any area unnecessarily. That wastes water and
encourages weeds.
Winter will kill a lot of weeds, but only temporarily. The perennial
weeds will sprout new leaves. The seeds of annual weeds will germinate before
anything YOU are growing. Diligence is the key. (If you could see my garden,
you would really laugh here!)
The REAL secret is to adopt a gardening style that disguises the weeds until you have time to deal with them. That leaves out the formal gardeners.