How to biologically control weeds

biologically control weeds

For many people, indeed most people, weeds are a nuisance which must be removed from the garden as quickly as possible. While, indeed, weeds can get in the way, can take water and nutrients from the soil needed by other plants and are often unsightly, many of those that we call weeds do have beneficial uses. For example, they attract the insects which would otherwise attack your vegetables or flowers; they attract other insects that prey on the harmful ones, and, frequently, these weeds have medicinal and herbal uses.

It is true, though, that if trying to grow vegetables or flowers successfully it is important to ensure that your garden is as free of weeds as possible within the parameters given above.

There are two main kinds of weeds, the annuals and the perennials. The annuals flower and seed in one year, whilst the perennials spread by means of groups and some underground stems. Annuals tends to be more prolific because of the number of seeds produced but perennials are more persistent and difficult to remove.

It is very easy to go to the garden center and buy cans and sprays that can be used to quickly kill off every weed in your plot. The problem with such methods is that the contents of those cans and sprays are highly toxic to people as well as weeds. Children, especially, are vulnerable to the poisons and, therefore, it is advisable for that reason as well as many others to find non-chemical alternatives.

Your weed control starts pretty well as soon as you decide you want to grow your flowers or vegetables. The better the preparation of the ground before-hand, the less trouble you will have with weeds in the future. There are a number of ways to prepare the ground and some are as follows: –


If weeds are deprived of light they cannot flourish and will die. There are many materials that can be used to cover your chosen area including old carpet, cardboard and black polythene. With each of these it is important to ensure that they are securely anchored to both keep out the light and to prevent them blowing away in high winds.

The major disadvantage of this method is that it can take a relatively long time to clear the ground of weeds.

The advantages are that it is relatively easy, the weeds decompose in the soil and return nutrients to it.


This is a quick way of turning over the ground but does have certain disadvantages especially where there are a lot of perennial weeds. The underground roots and stems are chopped up by the blades and each small piece of root or stem becomes a separate weed.


There are two ways to go about hand digging. The first is to dig deep and bury the weeds and the second is to turn over just a few of the top inches of soil and remove the weeds by hand.

Each of these methods makes the land available quickly and costs very little. However, they are both very hard work and that might be a limiting factor for some people.


If you have done the initial work to clear up the land of weeds but are not yet ready to plant your main crops, it is possible to plant some kind of cleaning crop that will help to keep down the weeds and improve the soil fertility.

The kinds of cleaning crops that can be used are such things as: –

Clover and other green manures (this is especially good for improving the soil fertility)


This method can be used on its own or as part of one of the methods shown above. It is a technique that should be used sparingly especially by those who are environmental conscience as the flame thrower will be using fossil fuels.

All of the above methods are for clearing ground of weeds in preparation for planting. We need to consider the methods to be used for maintaining a weed free garden.

The weeds need first to be discouraged from growing and controlled when they inevitably do grow.

Mulching will work to discourage weeds and this can be achieved by putting the mulch on the areas of bare ground not occupied by your cultivated plants. The mulch could be any of the following:-

  • Grass cuttingsLeaves or leaf mold
  • The newspaper covered with old straw, hay or grass cuttings
  • Wood chips
  • Black polythene (plant through the polythene)
  • Gravel (for such things as Alpines)

I am a great believer in planting as densely as possible and this will not be a problem if your soil is fertile and filled with nutrients. It has the added advantage of keeping down the weeds.

In some areas such as an orchard where you have large shrubs or trees you could plant a cover crop such as grass and this need not be as often as you would cut your lawn.

It is inevitable that no matter what you do, some weeds will still grow and only constant attention to your garden will keep them from becoming a nuisance.

Depending on the size of your plot and the amount of weeds you have allowed to get through, you can use the hand weeding technique which is simply a question of going down on your hands and knees and pulling the weeds by hand (most will come up quite easily especially after a light shower) or you could use one of the many types of hoe available and cut off the roots of the weeds with a sharp blade of the hoe. It is a vital that you take care not to damage your cultivated plants at the same time.

Weeding can be quite relaxing if it is done regularly and you do not have to deal with huge tracts of perennial weeds. How hard or easy it is will depend on the preparation work you do. It is certainly never necessarily uses harmful, toxic chemicals as this article has demonstrated.

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