(Numerous species) Weeds in the lawn spoil its overall appearance, especially when they start to flower. If you want your lawn to be weed free, then you’d better get rid of them quickly.
As any plant “growing in the wrong place” is regarded as a weed, then any non-grass plants that grow in your lawn can be regarded as a weed.
Many of our weed species are naturally-occurring or wildflowers, so make sure if these are growing in your garden that they don’t produce seeds that can blow into the lawn.
Grasses produce thin, upright leaves, which are easy to mow at a regular height to produce that thick green growth that most people consider to be what a good lawn should look like. Any other plant growing in the lawn spoils its overall appearance. Most of these are broad-leaved weeds, many producing low-lying rosettes of leaves that smother the grass and kill it. Others produce creeping stems that spread throughout and all over the lawn and then produce masses of “unsightly” flowers.
However, some coarse-leaved grasses, such as Yorkshire fog (Holcus lanatus) and annual meadow grass (Poa annua), are classed as “weedy grasses” and if present in the lawn will spoil its overall appearance.
Common lawn weeds include the following:
Not strictly a weed, but moss [LINK] is one of the commonest problems growing in the lawn.
As with most weeds, never allow lawn weeds to become established, and certainly don’t allow them to flower and produce seeds. This will make it more difficult, and more time consuming, to fully control them. Early identification and eradication is important to stop them taking over the lawn.
Keeping the lawn growing thick and strong all year round will help prevent weeds from becoming established in the first place.
Lawn weeds that produce a rosette of low-lying leaves are usually easy to control by digging them out. Those with trailing and creeping stems are more difficult – and certainly more time consuming – to control.
A hand trowel can be used to dig out lawn weeds. Just remember to dig out the roots too, especially those perennial weeds with deep taproots, such as dandelions. A thin-bladed weeding knife, weeding trowel or rockery trowel are usually better for this. Long-handled weed pullers and weed extractors are also available and reduce the back-breaking strain of weeding with hand tools.
Coarse-leaved grasses
It is often recommended to slash through the clumps of these grasses with a sharp knife before every mowing. However, this is rarely effective and, if it does work, takes several months. It is far better, easier and quicker to dig out the clumps and then reseed the bare patches left behind with fresh grass seed.
There are a number of weed control options available to treat lawn weeds. In addition to traditional weedkillers there are now also a range of more natural alternatives.
If you have a severe weed problem that covers much of the lawn, it might be best to kill the whole lawn with a weedkiller, and then start again from scratch.
Otherwise, use a lawn weedkiller. These are selective and, if applied correctly as per the manufacturer’s instructions, differentiate between the thin, upright growth of grasses and the larger leaves of broad-leaved weeds. This means they kill the weeds, but leave the grass unharmed. Obviously, because of this, they have no effect on coarse-leaved grasses.
If there are only one or two weeds present, spray them as soon as possible with a handy, ready-to-use lawn weedkiller.
Where weed cover is more extensive, it will be easier and quicker to treat the whole lawn. Granular and liquid weed and feeds are available or use a liquid lawn weedkiller.
Use lawn weedkillers from late spring to late summer when the grass and weeds are actively growing. Choose a day when rain isn’t forecast – the longer the weedkiller remains on the leaf the better. Don’t mow the lawn for at least three days before treatment, to give the weeds plenty of time to produce a good leaf area to treat. And don’t mow the grass for at least three days after treatment to give the weedkiller plenty of time to get to work.
Use weedkillers safely. Always read the label and product information before use.
Lawn weeds often become established on lawns that are growing poorly, are on poor soil, or are not maintained and looked after properly.
Improve the growing conditions for the grass – reducing shade, raking out thatch (dead grass and other debris) and reducing soil compaction by aerating with a hollow-tine aerator and applying a lawn topdressing. Feed the lawn throughout the year to keep the grass growing strongly – this encourages it to grow more thickly, reducing spaces for weed seeds to germinate and helps the grass out-compete the weeds. And, most importantly, mow regularly to keep the grass at a height of around 4cm (1½in) high all year round, 5cm (2in) or even more in deep shade.
Never allow weeds to flower and set seed. Although this should be pretty easy in your garden, it’s more difficult to stop seeds blowing in from a neighbour’s garden, any surrounding fields and waste ground and even further afield.
