Don’t let the name fool you, crabgrass (or Digitaria to use its scientific name) may well be a type of grass but it will totally spoil the look of the rest of your lawn if allowed to propagate. To most people crab grass is as much of a weed as dandelion or chickweed, so lets look at how best to deal with it before it has a chance to become an issue to you.
How Does Crabgrass Grow?
Crabgrass is able to thrive because it will happily grow in hot and dry conditions, conditions is which your turf will struggle to grow. It is also successful in part because the structure of the plant stems from a single root point low in the soil, from which the ‘crab leg’ like stems grow outward without any trouble. So it doesn’t need a lot of space to get started, and will soon take over, continuing to grow throughout the warmer seasons. To make matters worse, a single crabgrass plant can produce over 150,000 seeds, so you can see just how much of a problem it can be if even a tiny fraction of those germinate successfully
How Can I get Rid of It?
The best strategy for dealing with crabgrass is, like most things, to be preventative rather than have to deal with the problem head on. Crabgrass specific weedkillers, or turf building weed killers are widely available and are best applied during the spring months before the crabgrass will have had a chance to germinate. In addition to applying chemicals, it also pays to be diligent with keeping an eye on your lawn, removing any weeds quickly should they appear, and if any dry or dead spots appear on the lawn, you should begin over-seeding the area immediately before the opportunistic crabgrass has a chance to move in
If you can you should also set your lawn mower cutting height as high as possible. The longer grass provides a greater level of shade across the lawn, which actually prevents crabgrass from being able to thrive. As great as short lawns look, they are far harder to keep weed free.
Finally you should also aim to water your lawn infrequently, but when you do water you should aim to water thoroughly, up to 75mm of water across the whole lawn will give the grass a good drink, and although it will initially give the crabgrass a boost too, it should ultimately put the grass in good stead to thrive and take the place of the crab grass.