Types of Garden Weed Killer and How They Can Kill Weeds
Garden weed killer can be a great help to the gardener. There are three main types: total weed killers that will kill all plant life for long periods; selective weed killers used to kill broad leaved weeds in grass, leaving the grass unharmed ; and the latest type, a total weed killer which has no residual effect on the.
Total garden weed killers which have a long life should be used only on paths and other areas where plants are not to grow. If they are used to clear an area which will later be planted, then a period of several months must elapse between application and planting so that it can be leached from the soil. Some of these weedkillers tend to creep in the soil so must not be used too close to trees, lawns or borders or these are likely to be affected. Others are obtainable which will not creep, and one of these, a simazine based garden weed killer, is particularly long lasting and will keep a path or drive clear of all weeds for a year or more. But it also means that the sprayed area will be totally unsuitable for planting of any type for an even longer period.
Selective garden weed killers are particularly helpful for lawn culture, for they do not harm grass if applied at the correct rate yet they keep down the weeds which grow in the grass. Two or three applications a year should keep any average lawn free from weeds.
The third type of garden weed killer has been described as a chemical hoe, for it is designed to act in much the same way. It acts on the green part of a plant only and when it touches the soil it is completely inactivated. So if there are weeds growing in the rose bed or thethey can be sprayed with this paraquat based weed killer and the weeds wetted will die in a matter of a day or two; no green part of the rose bushes or the vegetables must be touched by the liquid. Brown tree or bush stems will not be affected and soil will not be contaminated. It is thus possible to spray a weedy area one day and a day or two later plant in the same spot.
All of these weed killers are in liquid form with one exception.
The exception is a selective garden weed killer used on lawns for killing broad leaved plants. This is a lawn sand and is generally marketed in conjunction with a lawn fertilizer so that weeds are killed and the lawn fed in a single operation. This powdered or granular form of selective garden weed killer can be spread by hand or by a special spreading machine which is merely pushed over the lawn and allows regulated portions of the material to fall on to the grass.
Liquid weedkillers are usually diluted with water and sprayed by means of a watering can or similar device. Instead of the usual watering can rose, special spray bars are available which spread the spray to cover wider areas, or to confine the spray to certain well controlled areas. It is wise always to keep a special watering can for weedkillers and to mark this clearly.