Organic weed control methods are usually simple, cheap and avoid the toxic side effects of herbicides. Hand weeding is one of the basic ways of controlling weeds organically in your garden. Concentrate on gardening one small area you can definitely manage, and gradually enlarge it. Organic weed control means avoiding nasty chemical herbicides, so leave the rest wild until you’re ready.
Here are a number of techniques that can be used in conjunction with each other in order to minimize the amount of weed growth in your garden. Cultivated areas need weeding on an ongoing basis. There are weed seeds carried around by wind, animals and on the shoes and clothing of people. Soil borne seeds are also lying dormant and waiting for the right conditions to sprout. Simply pulling or killing weeds will not eradicate the weed problem. More seeds will sprout almost as soon as the soil is exposed to moisture and light. Sheet mulching is a way in which to put down an organic weed barrier. This barrier prevents the germination and eventual emergence of weeds through your mulch, by inhibiting light. Underneath this weed barrier grasses and weeds die and quickly become food for earthworms, and as the mulch breaks down it will provide nutrient back into the soil.
If you have large areas of weeds you can simply smother the area with sheet mulch. Here’s how you do it. First water the soil the day before so that the soil is moist, then lay newspaper six sheets thick to cover all the soil and weeds. Place the newspaper sheets right up to the edge of plants making sure there is overlapping of paper so the weeds can’t get to the light. Six sheets of newspaper is enough to trap the weeds, and allow air into the soil without harming garden plants. Lay a 15 cm thick layer of mulch over the paper. Compost, dead leaves or any type of organic mulch can be used. Avoid digging the bed for at least 3 to 6 months so that no weed bulbs or seeds get a chance to re-grow.
After a few months the weeds will have starved to death and the bed will be full of organic matter ready to plant out with garden plants. After 6 months or when the sheet mulch has become thin simply reapply. I know some gardeners who don’t even bother using mulch on top of the sheet as they simply apply thick sheets of overlapping newspaper or cardboard. Because these materials are porous they allow air and water into the soil but restrict sunlight, thus preventing weed germination. You can cover large areas very quickly. For a small vegetable garden you could sheet mulch in a matter of minutes, and then you will have prevented weed growth for a number of months, the technique can also be used to convert grassy areas to garden beds. It is so simple but so effective, lay down sheets of newspaper and top with mulch, it should take a matter of minutes, not hours, but it will save you so much time and effort.
Some landscapers like to use permanent barrier membranes such as plastic, instead of newspaper sheeting. Buried plastic barrier membranes kill off soil life, as they prevent nutrients, moisture and air from entering the soil which will destroy microbial activity, necessary for the health of the soil. Over the long term the soil becomes dry and suffocated as it is effectively starved. The aim is to starve the weeds, not the soil. Under no circumstances would I advise plastic sheeting as a weed control, having previously seen the effects and having worked to rehabilitate soils that have been damaged by this method of weed control. With newspaper sheets we can starve the weeds and enrich the soil at the same time!
For topical weed control without chemicals, try vinegar. It’s the acetic acid in vinegar that gives it its herbicidal qualities. Vinegar used for culinary purposes is relatively low (5%) in acetic acid, so repeated applications will be necessary if you’ll be applying it on mature weeds. When using vinegar as herbicide apply it directly onto the weeds, since vinegar is non selective and will harm plants that are inadvertently exposed to it. Vinegar also eats concrete so be careful if you’re using it on weeds growing within paved areas, pouring boiling water on weeds is a much better option in these circumstances.
Another reason for not using artificial weed killers is that this prevents you composting any of the dead weeds. Doing so would recycle the toxins which may harm plants that are supplied with your compost. To dispose of your weeds you can either throw them out in the rubbish or you can add them to your compost, but in no circumstances should you throw them back on to any part of the garden as they would easily grow and re-establish in your garden. You must be diligent in making sure that every tiny scrap of weed (from the root to the tip) is disposed of, and not dropped back on the garden. If you don’t have time to remove weeds before they flower, make sure that you cut the flowers and dispose immediately, because if you let them go to seed in your garden, you will be constantly fighting an uphill battle. You need to prevent seed distribution so don’t let the seeds escape.
Also it is important that you don’t compost weeds directly. In commercial composting operations weed seeds are killed by maintaining high temperatures above 60°C. Such temperatures are usually only achieved with very large carefully managed piles that are not realistic for the average home gardener. There are two main ways in which weeds should be prepared before you add them to your compost. Solarisation is the easiest method to destroy the viability of weeds to reproduce. Put bulbs, seeds and roots into a sealed black plastic bag and leave it to bake in the hottest sunniest part of your yard for a week or two. The contents will be destroyed, and then the residue can be composted. Drowning is another alternative, put the weeds inside a bucket, fill it up with water and put a lid on top. A month later there is a nutrient rich soup to feed the garden, and the weed residue can then go into the compost.
If you really don’t have time to tackle a large patch of weed that doesn’t affect cultivated areas, leave it and don’t worry, just make sure that you cut weeds down for composting before the seeds disperse. Weed control chemicals are intended for small hard to deal with areas. Don’t apply deadly weed killer to a large area of garden as sterile weed killed land stagnates and accumulates undesirable chemicals and will ruin the soil over time. Once you get it under control weed problems will soon fade away with sheet mulch, gardening tools and persistence, with no need for harsh chemicals and protective face masks.
