Killing weeds; gardening

I'M GETTING fed up with PC attitudes to weeds: a weed and a wild flower are not the same thing. Of course if I find a foxglove, a corn poppy, or a primrose seeding themselves in my flowerbeds, I will welcome them as a good sign about the place I live and leave them alone. They can take thrive alongside the other garden plants without imposing themselves and without the characteristic colonising dominance of pernicious weeds. But docks, ground elder, couch grass, bindweed, mare's tail, brambles, nettles, groundsel, fat hen, chickweed, goose grass and rosebay willowherb will all carpet an area in a matter of weeks. They starve, strangle and dry out any other plant in the vicinity. Of course I don't want these. Of course they must be eradicated.

What makes a weed pernicious is either its root or its propensity to flower, set seed and produce thousands of offspring. If a corn poppy sets seed, it can produce several hundred offspring; with fat hen, you are talking several thousand. One year's seeding, seven years' weeding.

The good news is that with brambles, nettles, and the annual weeds like groundsel, fat hen and chickweed, what you see is what you get. If you dig out the roots, that is the end of the problem (and even if part of the root remains, they will not regrow). Annual weeds don't need quite as much elbow grease as nettles and brambles, but the same principle applies. You want to get rid of every one before it has time to flower and set seed.

As the soil warms up, annual weeds will soon be cropping up all over the garden, smothering any bare area of ground. The seeds deposited from your own weeds last year, or those that have floated in on the wind from next door, are germinating in the spring sun. Get in now and remove them with one of those three-pointed claw-like hoes. With these you can disturb the top 5cm (2in) of soil and displace the weed roots with minimal effort.

If there are loads of perennial and shrub roots, use a hand fork instead. Annuals growing through gravel, between paving stones or in cracks in walls can be effectively scorched with a small flame gun. These are available from organic suppliers like the Organic Gardening Catalogue (see below). Once you have got rid of these weeds, carpet the soil in a 5cm (2in) layer of mushroom compost or composted coir or bark. This stops seeds from dropping in on top or appearing again from below. Leave a 5cm (2in) band of bare, unmulched soil around the perennials and shrubs and either side of any row of annual seed that you have just sown.

This is another reason not to broadcast seed: you won't be able to tell weedlings from seedlings if you have scattered your seed willy-nilly, and with seedlings appearing all over the place, mulching is almost impossible. Once you have your layer of mulch all over the garden, though, you will hardly have to weed again.

Then you come to the five nightmare weeds, a group which includes couch grass, ground elder, mare's tail and, worst of all, bindweed. These are perennial plants and it is their roots which cause the problems. One clump will create a giant spaghetti-like clot of a rootball up to a metre wide and deep. Docks are the fifth horror perennial. They don't have such a great root volume, but their tap roots can grow to a great depth.

If you leave any part of the root of these five weeds in the ground when you try to dig them out, it will form another plant. Reluctant as I am to advocate the use of weedkillers, glyphosate is the only way to get rid of them. If you apply it to the leaves, the plant absorbs the poison and draws it down into the root, killing off every last inch.

I have tried cutting docks to the ground again and again, like a farmer with his topper, thinking they might weaken, but our docks have grown bigger with each new cut, like hair. I have tried digging them out, but whenever I have been unable to remove the very tip of the root they have erupted again just as strongly. I have tried teasing out bindweed roots, following them through the ground with my fingers, but I must have left some broken bits. There is certainly more of it springing up in a bed I spent hours on last year.

If you are very patient, you can lay down carpet or a black plastic mulch and your perennial weeds will die in a year or two, but you can't do that in a tightly-packed, established perennial bed. You will have to shrug off purism and paint a few leaves with weedkiller. I administer glyphosate to my garden in the way that I resort to antibiotics for my children. Perennial weeds are like an illness. Chemicals have a role, but only in specific cases, and as a last, rather than a first, resort.

Dig up young brambles and nettles as well as the annuals before they grow higher than 20cm (8in), getting rid most of the root. If the plants are larger and well established, you may have more of a problem as they may just keep reappearing. Again, glyphospate is the last resort.

You can buy glyphosate at the garden centre under the brand names Round Up or Tumble Weed. To apply it, mix it to the correct concentration and paint or spray it on to the leaves. Since the plant absorbs the poison through the leaves, do not cut the plant back at all before using the chemical. The more leaf you can paint, the quicker and better the effect. You need to apply it differently depending on the volume of weeds. If you have only a few weeds, use a 1.5cm (12in) paint brush, or finer. If you have more, use a small water-atomising spray. If you are taking over an overgrown garden and are tackling a jungle, a knapsack sprayer may be your only hope.

If you do decide to spray, screen off the plants you want to keep with a panel of wood or plastic. Spray now, while the plants are growing fast, and do it on a fine, sunny day so that the chemical is not washed off by rain. To be absorbed prop- erly it needs to stay on the leaves for about six hours. Once you have sprayed, leave the plant to die right down and don't weed it out. It should have turned brown in 10 to 14 days.

The only other plus-point to glyphosate, apart from the joy of having got rid of your most problematic weeds, is that it leaves no residue in the soil.

Flame guns (prices from pounds 25.99) from the Organic Gardening Catalogue, Riverdene Estate, Molsey Rd, Hersham, Surrey KT12 4RG (01932 253666)

sprinklers will be coming into their own in the next few months. Check them over to see that the roses still fit on the nozzle of your watering cans and haven't been too dented sitting on the floor of your shed. With a big dent in a metal rose, one area will pour with a gush, the other a dribble and you will need a more regular flow for watering delicate seedlings as they go out in the garden. Rubber hoses are a good, almost indestructable alternative to metal.

It is worth checking your hose pipe too. With th emodern, thin PVC you can mend a small leak with a bicycle punchture repair kit, but this does not seal well onto the thick, ribbed, old-fashioned type, which tend to perish in a kink. It might be time tobuy a new one. LBS, a horticultrual supplies mail order catalogue based in Lancashire have a good selection of watering cans, roses and hoses and are chepare than a garden centre. Ring them on 01282 873333 for a copy of their list.

And do you sprinklers need cleaning out with a pin?