The line between having few weeds and being overwhelmed with them is remarkably fine – and I want to help you stay on the right side of it. In a garden with few weeds, you can maintain beds and borders easily and quickly, with a little-and-often approach. In the opposite case, it’s a major job to keep your plot under control.
In my weed-free garden, some people ask, “Why not let a few weeds grow, they are good for wildlife?” I can only agree – they are an excellent habitat for slugs!
Weeds, by definition, are fast to grow so it takes a thorough approach to prevent reproduction. There is not really a middle ground of having a few weeds, because that is the tipping point between clean soil and weeds taking over.
With some clever groundwork now you can set up your garden to stay in an easy-to-maintain mode. Intensive mulching is a good start, depending on what is currently growing.
You must then stay vigilant and remove any surviving perennial weeds until even they give up. This approach is not arduous, but it does take regular attention to start with.
How to get rid of weeds in your garden
Since starting a garden at Homeacres in Somerset I have had the opportunity to test the effectiveness of different mulches. It’s a three-quarter-acre plot which had been a nursery in the Sixties, growing dahlias and chrysanthemums, many under glass. The owner died, his widow stayed on and brambles took over.
The greenhouses fell down, one by one. I only discovered this after buying the property, by which time there were no structures and hardly any garden visible: just brambles, buttercup, dandelion, ivy, celandine, couch grass and a selection of other perennial weeds.
That was in winter. In spring new weeds appeared, such as creeping thistle and bindweed.
Apart from woody stems, docks and ivy, I cleared all these weeds by smothering them. I achieved this without any digging or soil disturbance. (In a wet winter this would have been impossible anyway.) With a no-dig, mulching approach, you can carry on in all weather.
My main area of new garden was on rough and weedy pasture, which I covered in winter with 2in-6in (5cm-15cm) of compost to create raised beds. On top of the more shallowly mulched beds (ie about 2in of compost) I also laid covers of polythene or cardboard. All the strips of pasture left between beds were also covered with cardboard.
During the first spring and summer, on the deeply mulched areas (ie 6in of compost) with no polythene or cardboard, I used a trowel twice weekly to remove every regrowing stem of perennial weeds.
By August the only survivors were field bindweed and a few shoots of previously rampant hedge bindweed. There had been a lot of couch grass in some areas; it’s all gone now.
On the beds with shallower compost and a covering of polythene, I removed the latter in early June to plant, then used a trowel in the same way to remove the few, persisting weeds.
To compare the no-dig method with digging, I set up two experimental beds, using a sharp spade to turn over the dense sods. These beds grow the same vegetables as their neighbouring, undug beds. So far the growth is similar and yields are closely matched: for example, two beds of 5ft x 16ft gave 104kg each in 2014.
The undug beds grew fewer weeds, although that comparison does depend on the compost used. My well-rotted cow manure contains fat hen and clover, but the seedlings are not difficult to hoe or rake off. The disturbed soil of the dug beds constantly throws up new flushes of weeds as the seeds are exposed to light.
How to stop perennial weeds for the long-term
Perennial weeds are the most difficult to eradicate: they survive winter, often invisibly with dormant roots, which grow an explosion of unwelcome leaves in early summer.
Bindweed is a classic example. It is a laborious process to dig, find and remove the offending roots. This is why I recommend you mulch instead, to exclude light from all new shoots of perennial weeds (apart from docks and woody plants like brambles), until their parent roots are exhausted.
There are many suitable mulches, such as polythene, which is quick to lay, or cardboard. Each piece must be overlapped, and a new layer placed on top within three months. Make sure that all edges are secure, with no light penetrating.
When using a thick mulch of compost, depending what weed roots are currently there, some new shoots will sooner or later need the attention of your trowel, until their parent roots eventually die.
Enduring exceptions are field bindweed and marestail – painting their leaves with glyphosate is worth considering here.
My neighbour Penelope Hobhouse used glyphosate to clear soil of all weeds, then plants into the undisturbed soil.
Compost mulch really works
Compost, including well-rotted manure, is more attractive than plastic and you can plant into it straight after spreading. Weed leaves and roots carry on decomposing underneath while your plants are happily growing above, until they can root into the soil’s channels of dead weed roots.
There are plenty of air holes left by those roots and the soil needs no loosening at all; the undisturbed worms are doing that.
Small, annual weeds die under 2in-3in (5-7cm) of compost, but perennials need a deeper layer. If you can run to a 6in (15cm) depth of compost to cover the weeds, including all the ones in the table, you are halfway to eliminating them. The other half is regular use of a trowel until they finally expire. I love my copper trowel for this, because it slides so easily in and out of the soil.
Copper does not rust and keeps a smooth patina with age. Also, the blades are thinner than on steel tools, perhaps because of the price of copper. The smooth working is particularly true when working compost-covered soil, which has a softer surface.
Why tackling weed seeds is key to solving the problem
It is always discouraging when new weeds germinate, but timely intervention can save the day.
Old gardeners say, “Hoe them before you see them”: develop a habit of looking for those first green shoots of weed leaves, then hoe, rake or scuff the surface when they are still tiny. It is so much quicker than hand weeding, often killing hundreds of potential weeds in a few minutes: two strikes in early spring sets you up for an easy summer.
Another benefit of this little- and-often approach is that you, the gardener, stay more involved. Go hunting for weeds and you’ll soon spot other plants in need of attention – and that is good gardening.
Most common garden weeds
Bindweed, field (Convolvulus arvensis)
Time for roots to die: Two years, even then some weak survivors. As difficult as marestail but smaller, weak and manageable after a one-year mulch.
Bindweed, hedge (Calystegia sepium)
Time for roots to die: One year, a few weak survivors. Pull any white roots seen after removing polythene mulch.
Couch grass (Agropyron repens)
Time for roots to die: Up to a year depending on initial vigour. Yes, you can be rid of couch grass completely.
Dandelion (Taraxacum officinale)
Time for roots to die: Four to six months. Remove any new shoots with a trowel, in spring mostly.
Ground elder (Aegopodium podagraria)
Time for roots to die: Up to a year. Not deep, dig out if beds are empty – but mulching is easier.
Thistle, creeping (Cirsium arvense)
Time for roots to die: Six to eight months depending on vigour. Simple to pull survivors.
This article is kept updated with the latest advice.