Kitchen Garden Magazine

Grow your own fruit and veg with the UK's No. 1 Kitchen Garden magazine

Get on top of weeds

As it's peak time for weed growth Bob Flowerdew has some top tips for keeping these unwanted plants at bay

This is the month when everything in the garden grows like Topsy. The days are long, the soil warmed up, and fertility and winter’s rain are not yet depleted. But not just the crops, the weeds also grow. And it is now they are at their most competitive and need the most effective control.

Now I spurn chemicals and even if I didn’t there would be little that could be used safely and easily among the mixed crops in the vegetable plot. The traditional option of hoeing is the first recourse but there other possibilities. And although regular hoeing is a good choice it can be made easier and done with less frequency if performed well.

Up till now weed seedlings growing among new crops have been an inconvenience, unsightly and a potential problem. (Note: I am referring to new weeds from seed not any well-established ones which should have been got rid of months ago.) However from now on weeds will be starting to flower and seed, or if perennial will start to get too firm a grip on the soil. Worse, their roots and foliage now become much more competitive robbing our crops of air, light and water. In particular some weeds are especially debilitating because they scavenge and accumulate certain minerals thus depriving our crops at this critical time.

In particular datura (thorn apple, pictured above) weeds are especially impoverishing as they rob the soil of phosphates; these can be recovered if the plant is dug in or composted before the seeds set. But if seeds do form then minerals, fats and carbohydrates are removed from the soil fertility and locked up inaccessibly in them until each seed grows, or rots.

Thus although it pains to watch the carefully hoed and raked plot of last week become a verdant quilt of living green almost overnight really one should rejoice. Each little seedling is now a soft succulent morsel easily killed and quickly rotted.

Each is a tiny piece of free green manure; of almost instantly accessible nutrients for the soil solution and our crops. Until the moment each emerged from its seed all those nutrients were locked away inside where they had waited since robbed from the soil long ago.

A flush of weeds may thus require dealing with and take some time and effort. But it is also a huge source of fertility and moisture waiting to be made available to your crops.

Thus it can be argued that flushes of weed seedlings, where they are not actually close to the crop plants, are really a green manure waiting to be incorporated, acting as miniature windbreak hedges, and as sacrificial snacks for the slugs.

For if there are no weeds the slugs and other pests will be forced to eat your crops even if they don’t like them! So there is much to be said for allowing weed seedlings to blanket the earth with a fuzz of green. But only as long as you can kill this off when required and keep it from choking your plants up till then.

Invert weeds

Another technique entirely is the inverted slice. This is very useful when it really is too wet and claggy to hoe. First the area immediately around each crop plant is cleaned by hand. Then with a good clean sharp spade, thus preferably stainless steel, mark out then skim off the top half inch of soil and weedy fuzz just as if it was turf. Simply invert and replace each ‘turve’ as you go lapping them carefully to cover any weeds pushed out from under the last one. Sure some re-grow but it gets most and they rot in situ pretty well. However you have to be careful when you come to hoe again not to bring the buried weeds up into the light again before they have yellowed and rotted.

Smother the weeds

Covering weed seedlings with a light excluding mulch may kill if thick and dense enough. Grass clippings laid down in a thick pad go horribly gooey and smelly and poison roots with their leaching. But if the clippings are put down in a layer just thin enough to hold down the weeds they work well. Then each week thereafter another thin topping of grass clippings is applied to any weeds that make it through. Putting a sheet of wet newspaper down before the first layer makes this work better and less grass clippings are needed.

I also find just laying down folded wet newspapers works remarkably well –though ugly and prone to blowing around as they break up. Either with or without paper a grass clipping mulch is really good around potatoes. They have to be earthed up anyway and the clippings do a good job at covering any protruding tubers and preventing weeds. More clipping mulches can be applied either side of a row of peas, around climbing beans, brassicas or sweetcorn as long as they do not pile deep around the stems as then they may cause rots.

Woven plastic sheets are effective but difficult to keep in place in the spaces between most annual crops though far more useful with perennial crops such as strawberries and bush fruits. Wide-spaced annual crops such as cabbages can be grown through a woven sheet mulch and are much cleaner for it with less slug damage. Tomatoes do very well this way, as do squashes and pumpkins. I find although newspaper, cardboard or plastic sheet does encourage slugs and sometimes rodents, underneath – the woven sheets, if well fitted, also trap them there so the crops above ground end up cleaner! And if the sheets are simply rolled back then the birds will soon clear any slugs for you.

For more see this month's issue, available to buy online!

Copyright information

© Mortons Media Group • | Subscribe | Renew | Buy current issue | Kitchen Garden offers shop