More effective weed control

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 grow, the weeds also. 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 amongst 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 amongst the 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, Thornapple, 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 it’s 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 wind break 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

Hoeing, as said above, is the most usual method of controlling weed seedlings but can be arduous if you have left it till the green fuzz stage. It will be incalculably easier if you; 1. Sharpen your blade every ten minutes, 2. Clean your blade every five minutes- fibrous roots often pack around the edge, 3. Work carefully around each plant first, then clear the rest. If they are all small they can be left to wither and rot in situ, if bigger they are best raked up and composted. Of course you already know how important it is to hoe on a drying day. This quickly kills hoed out wee seedlings and weakens the bigger weeds leaving them too exhausted to re-root. But, surprisingly, if it won’t stop raining then hoe anyway- better to disturb them than to leave them longer to get stronger and we can at least wash the soil off their roots. (Do not forget to sharpen your hoe FREQUENTLY.)

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.

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 there-after 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.

A carefully used horticultural flame gun, hobby blow torch, hot air gun, steam cleaner or even just boiling water can all be used to kill small weeds effectively if due safety precautions and accuracy are applied. After all it takes very little to kill small seedlings, but as they get more established it gets progressively harder. Grasses are one of the quickest weeds to establish. They also become partially resistant to most methods of killing them because they grow from the leaf base not from the tip or buds. So anything that just removes most of their leaves only weakens them. They soon regrow. Also grasses and other weeds that have made a root system with below ground buds can recover soon after the top growth is removed.

This is why it is important to weed regularly. If it takes a root or bud a week or so to grow and unfurl a new leaf into the sun then fortnightly or less frequent weeding will be ineffective. Every new leaf will soon make back the energy it took to grow and the root system will proliferate. Weeding well at fortnightly or less intervals will remove each new leaf formed before it can recoup anything. Thus the root system can be relentlessly and systematically impoverished, weakened and will rot away. It also takes new seedlings about the same time to germinate and emerge, so if you hoe frequently then these are chopped and re-interred before they have barely become visible. As the old saying goes “If you hoe when you can’t see a weed then you’ll never see one.”

Of course, as stated earlier, you should already have eliminated perennial weeds in previous seasons! But if you have not done so it is risky to leave seedling weeds for any time at all as they obscure the more dangerous perennials. All of them must be ruthlessly exterminated by more rigorous and regular hoeing than will suffice for just seedlings on their own. Hoe, with a regularly sharpened thin bladed hoe, at least weekly, until new shoots stop appearing then you can reduce to fortnightly hoeing.

Once you have control of the weedy flushes of this month and next the task can lighten. Fewer weed seeds germinate in the drier days of summer and even if they do they become less problematic. Indeed a covering of weeds amongst such as ripening onions merely take up nutrients and water and help the crop mature. (Though too dense and they may make it damp and rot!) However although there may not be any flushes do not stop the weed control though once every three weeks will do, after all you do not want any getting away and setting seeds! Later when the days shorten and moisture returns you will need to weed regularly again to prevent new flushes from establishing themselves too comfortably. Unless you want them as winter cover and a green manure that is.