Winning the battle against Perennial Weeds

Perennial weeds are those pesky hard to kill weeds that die down in winter and re-emerge now in spring. They can be difficult to control and include weeds like bindweed, ground elder, nettles, Japanese knotweed and couch grass. The best time to tackle these weeds is in spring and summer while they are actively growing.

Combining several of our eradication techniques should ensure good weed control and minimal regrowth.

Eradication methods


Barriers whether laid vertically or horizontally physically block the speed of weeds. Vertical barriers include edging boards and upended paving slabs whilst horizontal barriers include laying a permeable weed-suppressant fabric (available from our garden centres) over a cultivated and prepared area. You plant through the membrane making a cross cut in the fabric to allow you to sink the plant through. Late winter and early spring is the time to do this before the weeds start to grow.

This technique is effective against the growth of grass in your borders ad suppressing regrowth of old weeds. Vertical barriers are great to stop the spread of weeds from or to a neighbouring plot.

Digging them up

Without a doubt this sone of the most effective control methods providing you avoid breaking roots and or rhizomes when you dig. Use a hand fork or weeding tool to make the job lighter work. If you have to cover a large area then this can be hard work.


Mulches help suppress annual weeds like dandelions as well as improve your soil texture and moisture levels, Plus they can encourage beneficial soil organisms. Clear your area first (hoe the ground) then apply a thick mulch of wood bark or chips. The mulch should be 10-15cm deep ideally (4-6 inches).


Synthetic weedkillers are divided into three groups…

a) Unselective – these kill anything green. Some are persistent and remain active in the ground for months. Chemicals like this should not be used on edible crops so always read the label before you buy to check it is correct for your home and lifestyle.

b) Selective – these kill a specific type of weed e.g. broadleaved weeds in lawns.

c) Systemic – the weedkiller gets through to the root as well as the leaves. The do not persist ion the soil but are toxic so again should not be used on edible crops.

All the above are best applied when temperatures are warm and weeds are actively growing.

Organic weedkillers tackle weeds quickly and effectively. Whilst they may not be as potent as systemic chemical based ones, they do mean that you don’t have to worry about children or animals. We sell the Neudorff range of organic treatments as we feel they are effective and safe.

Other methods

Heat is effective at killing weeds whether you pour water from pots after you have cooked your vegetables or soil a kettle to buying specially designed heat wand guns (that use gas or paraffin). Results can be quite slow and they do tend not to last that long as some of our other techniques.

Scraping the weeds from cracks in paving is effective but you may find yourself repeating the exercise several times and therefore may want to consider a weedkiller instead.

Leave them be

To give a balanced view on weeds, we must not forget that many weeds are actually beneficial and sought after by wildlife. If you can afford to let an area go a bit wild then do. Stinging nettles alone have been proven to support over 40 different kinds of insects! Nettles are also a magnet for other insect-eaters like hedgehogs, shrews, frogs and toads, at all times of year.

However you want your garden to look, our Exeter based garden centres have the tools for the job!