How to control weeds

You don’t need weeds in your garden for the very good reason that they require the same nutrients, light and water as other plants and so compete for them. By getting rid of weeds you are feeding the plants you love. But before you can do anything, you must know your enemy. Armed with the best knowledge and advice on weeds, you can decide upon the best plan of attack.

Types of weeds

What is a weed?

Quite simply, it’s a plant in the wrong place. There are four types of weed – annual, biennial, perennial and woody. They grow in most soils and situations and need different methods of removal.

Annual weeds

Although annual weeds, as their name suggests, die within the year, they reproduce through seeds, recreating thousands of them – and these seeds can survive dry and cold periods, not to mention travelling great distances. As the old saying goes, ‘one year’s seeding is seven years’ weeding’, which is why it’s a good idea to get rid of them before they set seed. Some of our most common weeds include: annual meadow grass, wavy and hairy bitter cress, fat hen, goosegrass, poppies, chickweed, speedwells and groundsel. These are best removed by hoeing or hand weeding.

Biennial weeds

Like annuals, these normally reproduce through seed, but during the first year the plant grows and accumulates food reserves, then flowers and sets seed the second year. Examples include: evening primrose, ragwort, hemlock, hogweed and spear thistle.

Perennial weeds

These weeds survive for more than two growing seasons and, in some cases, many years. If they are not removed, they can develop into woody plants. The deep and penetrating roots of these weeds make them a real challenge, however, and they can re-grow from the smallest segment so it’s vital to remove the whole plant. Common perennials include: nettle, ground elder, creeping thistle, dandelion, couchgrass and bindweed. These are best removed by hand or carefully applied chemical weed killers.

Woody weeds

In order to destroy these weeds, they must be dug up or sprayed with a chemical weed killer. The most commonly found plants from this group include ivy, holly, elder and bramble. If left to grow too big, these become more difficult to remove.

Preventing weed growth

Once weeds have become established, they are far more difficult to deal with. Deprive them of light to suppress their growth and prevent them taking over your garden. Here are a few quick and easy methods:

  • Gravel: a 5cm layer of coarse gravel around ornamental plants will suppress weeds.
  • Chipped bark: a 5cm layer of bark over beds and borders suppresses weeds, gives a decorative finish and helps insulate plants against frost.

Controlling established weeds

Many weeds can be controlled simply by using a few hand tools.

Hoeing

It’s best to choose a dry day so that the cut weeds dry up and die quickly.

  • Use a Dutch hoe: to control annual weeds. This tool enables you to cut through weeds without damaging plant roots.
  • Use a draw hoe: for chopping weeds in half.
  • Use an onion or hand hoe: to weed among closely grown plants.
Hand weeding

When weeding, try to choose a time when the soil is moist but the weather is dry.

  • Keep roots intact: hold the weed close to the soil, and then pull it out with the roots intact. Shake off the soil.
  • Wear gloves: and protect your knees with a knee pad.
  • Don’t compost: Do not put any weeds that have set seed on the compost heap – they will create more trouble next year!

Weed killer

Anywhere you do not want anything at all to grow, chemical weed killers are both useful and labour-saving. A weed killer works by destroying or blocking the water passages in plant leaves, stems or roots, so preventing growth and eradicating the weeds. Chemicals are best combined with other methods and should always be used with great care and strictly according to the instructions on the packaging. Keep them out of reach of children and animals, wear gloves and wash your hands after use.

Apply in spring or summer for best results, avoiding windy days.

Rain can ruin the effect of many weed killers.

Always identify the weed type before attempting to control it so the correct chemical is used.

There are all sorts of different weed killer types and brands available in several forms including gels, liquids and ready-to-use formulations.

For borders, use a paint-on gel formulation, applied to weeds that are growing where hand weeding or spraying is difficult without damaging nearby plants.

Use a liquid weed killer on paths, patios and drives.

Time-saving tips

  • As you potter round the garden, pull up any weeds you spot.
  • A dribble bar is an efficient, low-cost way to apply liquid weedkillers.
  • If you are tackling an especially large weedy area, start by cutting off weeds’ flowers and seeds.
  • The best way to remove dandelions is with an old kitchen knife. Keep the blade vertical and cut downwards in a circle around the weed. Lever the knife back and forth. Pull out the weed with its root intact.
  • Never let a weed see Sunday!
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