All Articles
Wage war on annual and perennial weeds
As the weather gets warmer, the weeds start to grow – and if gardeners didn't control them they would quickly overrun any garden. The secret is to get on top of them before they get too established.
One thing that you can guarantee in the garden, regardless of the weather conditions, is weed growth. As soon as the weather starts to warm up, up pop the weeds.
Weeds have adapted over hundreds of thousands of years to grow in just about every situation as part of their survival so weed control is something all gardeners have to do every year.
To help control weeds around the garden, it helps if you know a little about the different ways that weeds grow and propagate themselves. Basically, most weeds fall into two groups and even if you don’t know the name of the weed you are trying to kill, if you can place it into one of the groups you will be able to control it more effectively.
Annual weeds
These live for one season and all grow from seed lying dormant in your garden soil. As soon as the soil warms up the seed will germinate and the first thing you see is a blanket of small seedlings on the soil surface. If they are allowed to develop, annual weeds grow quickly, flower and then die after producing another crop of seeds that either fall to the ground or blow away.
Their roots are fibrous and if the plant is cut off at ground level, the roots will not re-grow and produce another plant. Annual weeds include chickweed, groundsel, hairy bitter cress, dead nettle and annual meadow grass and are generally easy to kill.
Perennial weeds
These weeds live for many years and each season the clump will grow wider or spread further. Many of them are invasive and will quickly smother ornamental plants. Growth starts in spring and during the summer, the weeds will flower and produce seed.
In autumn. perennial weeds die back to ground level. The roots remain alive and act as a food store over the winter months. The following spring the process starts again and the plant will grow larger.
Chopping off the top of a perennial weed won’t kill it as it will re-grow from the root. Perennials weeds are more difficult to eradicate and include plants such as stinging nettle, bindweed, couch grass, ground elder and docks.
Step one
Cultural control, such as hoeing off small annual weeds, is very effective, especially if it is done on a dry, sunny day to make sure the seedlings wither away.
Step Two
Contact weedkillers based on natural fatty acids are very good at controlling annual weeds. They work by scorching the leaves off in a matter of hours. If you kill the leaves of an annual weed, it can’t re-grow from the roots.
Step three
Perennial weeds can be forked out, but you need to remove every last piece of root. If you leave some behind, the weed will
grow back.
Step four
To control perennial weeds with weedkiller, you need to use a systemic product with glyphosate such as Roundup, Tumbleweed or Resolva. This is absorbed through the leaves and taken down to the roots where it kills the entire plant. For it to work well, you need plenty of leaf on the weeds to be able to absorb the weedkiller.
