Weeds are a bane for us gardeners. It’s that combination of persistence and resistance that makes them so frustrating! Weeds employ some pretty underhand tactics to get the better of us: breaking off bits of root that re-grow, throwing up seed heads that blow all over the garden, or reaching deep underground to evade capture. To outwit weeds you’ll need to wage a concerted campaign on several fronts, but it can be done, and without resorting to weedkillers. So here’s how you can win the war on weeds!
Know Your Enemy: Annual and Perennial Weeds
There are two enemies at work here: annual weeds and perennial weeds. Annual weeds complete their lifecycle – sprouting, flowering and setting seed – in one season. They’re easier to control but spread quickly by seed. Perennial weeds continue growing for a number of years but have far-reaching roots, making them harder to control.
Starting with a weedy garden can be intimidating, and demoralising. Begin your campaign to gain back control by cutting or mowing weeds to the ground, then cover with a light-excluding membrane or mulch to deprive the weeds beneath of life-sustaining sunlight. Black polythene is very effective for this.
Alternatively, use sheets of cardboard. Remove any staples or tape then position each sheet of cardboard with generous overlaps to make it harder for weeds to push through. Weigh the cardboard down to stop it blowing away. You will probably need to replace the cardboard as it rots down.
Perennial weeds with deep or spreading roots, including bindweed, ground elder and nettles can take a year or more to die off. But all those weeds will eventually rot down, helping to feed the soil for the plants that follow.
With the ground cleared it’s important to act quickly to remove any resurfacing weeds. Carefully dig out the resurgents with a trowel or fork, taking care to remove all of the roots. Fragments of perennial weeds can easily re-root and spread, so dispose of the roots away from your compost heap.
Another option is to submerge perennial weed roots in a bucket of water for at least a month until they turn into sloppy goo, which can then be poured over your compost.
Tackle recently germinated weeds in existing beds by disturbing the surface of the ground as soon as they appear. Use a sharp hoe to skim the surface and dislodge or slice the seedlings. Do this in the morning if possible, and on a windy or sunny day, so that the exposed seedlings quickly wither. Regularly sharpen your hoe so that the blade slices through weeds like a knife.
Act fast! A little effort now will save you considerable trouble later on. Revisit growing areas once a week to remove young seedlings before they’ve had a chance to establish.
Quell the Uprising
The adage ‘one year’s seeding makes seven years’ weeding’ is very true! Prolific weeds such as dandelion quickly spread if they’re allowed to produce seeds, so always aim to remove weeds before they get a chance to flower and set seed.
Keep on Top of Them
Organic mulches like compost and leaf mould help to suppress weeds, while feeding the soil for the crops you’re growing. Lay them around existing crops to give them an advantage over the yet-to-emerge weeds beneath. Mulching like this also means you can adopt a no-dig method of gardening. By sowing and planting into this top layer of compost, there’ll be no need to disturb the soil below, so the weed seeds within it will never reach the surface to germinate.
Take a look at the picture above as an example. The weedy strip is ground that hasn’t been mulched, while the clear ground either side beautifully demonstrates how a thick layer of mulch keeps weeds away and the ground nice and clean.
Resistance is far from futile! Consider covering bare soil with a cover crop or green manure to crowd out weeds and add valuable organic material. Fast-growers like mustards may be sown as late as autumn to cover over the soil surface in a matter of weeks. Weeds won’t get a look in! Then, just before the new growing season, dig them in or pull them out to reveal clear soil ready for planting.
Intensive cropping using leafy vegetables to stop light from reaching the ground is another efficient way to ‘clean’ the soil of weeds. Potatoes, for example, have masses of lush foliage that’s great at excluding light.
Every gardener should aim to keep soil covered as much as possible, whether through efficient use of space with multiple crops grown side by side, or with generous layers of organic mulch, or a temporary cover crop to nourish and protect the soil.
Peace at last! Once your garden is clear of annual and perennial weeds, you’ll want to keep it that way. Inspect new plants for lurking weeds like creeping buttercup and check that any bought-in manure or compost is well-rotted and free of weed seeds too. Keep compost heaps and potting mixes covered to prevent blown-in seeds from settling. And maintain clean tools and boots to minimise the spread of weeds.
Don’t let the weeds get you down: persistence pays off and once you’ve gained control hoiking out the occasional weed can be seen as a pleasure, not a chore. Have you ever had to battle with a weedy, jungle-like garden? We’d love to hear your stories – please do drop us a comment below.