Control Weeds Without Chemicals

All weeds can be controlled without weedkillers, but persistent or deep rooted weeds may be very difficult to eradicate. Ongoing control is likely to be necessary.

Annual weeds (which only live for a year) and ephemeral weeds (which live for less than a year) are the easiest to control, as they are usually shallow rooted. However, they can scatter seed prolifically, so usually reappear and require further control.

Deep-rooted perennial weeds (which die down in the winter and re-grow each spring) will re-grow from their roots if the tops are removed or burned off. They can be difficult to dig out and may grow up through weed barriers in time.

Weeds can be controlled whenever they are troublesome, which is usually in the spring and summer months.

It is a good idea to put weed barriers in place in late winter or early spring, as they work better as a preventative than when an existing problem requires suppression.

Tips To control weeds without chemicals

Manual removal and cutting back

Hoeing: Run a hoe over a bed or between rows to kill most weed seedlings. For maximum effectiveness, choose a dry day with a light wind, so that the seedlings will dry out on the surface of the bed rather than re-rooting into moist soil
Hand-pulling or hand-weeding with a fork: Pull up annual weeds by hand before they set seed. Perennial weeds should be dug out with as much root (or bulb) as possible, using a hand or border fork. Hand weeding is easiest on lighter soils and should only be attempted where it will not disturb the roots of garden plants. Further pulling may be necessary with persistent weeds such as bindweed or couch grass where small root sections left behind can re-grow into new plants
Weed knife and other weeding tools: A weed knife has a hooked end and is a useful tool for weeding between paving slabs and along path edging. Various other hooked, narrow-bladed or spiral-type tools are available for specific weeding jobs such as digging out dandelions on a lawn
Repeated cutting: In large weedy areas, repeated cutting to ground level over several years will weaken and even kill some weeds. This is usually done with a strimmer or sickle-type weeder
Flame gun: Scorch off weeds between paving slabs and on driveways by blasting them with a flame gun. Use only when the foliage is dry and allow sufficient burn-time for deep-rooted weeds, such as dandelions, to be killed

Weed barriers

Mulching: Use deep organic mulches such as bark or wood chip to smother weeds around plants. To be effective, keep them topped up to a minimum depth of 10-15cm (4-6in) to smother established annual weeds. Keep woody stems clear of mulch to prevent rotting
Edging boards or strips: These can be used to edge lawns and grass paths to prevent unwanted grass growth into the border. Especially useful where invasive rooted grasses such as couch grass are a problem
Root barriers: These can be inserted into the soil to stop the spread of perennial weeds such as ground elder and horsetail into neighbouring areas or gardens. They can also be used to restrict invasive plants such as bamboos, or suckering trees, shrubs and raspberries. A straight barrier can be formed from paving slabs or corrugated iron sheets, but for a flexible solution use a tough fabric like Rootbarrier available from Greentech

Weed-suppressant fabrics

Groundcover or landscaping fabrics can be laid over recently cleared soil to suppress re-growth of old weeds and prevent new weeds from establishing.

There are a number of different weed suppressant fabrics available, each with its own advantages and disadvantages.

Spun materials: These are usually made from plastic fibres bonded together to form a sheet. They can be used in most situations, both short and long term, but are best covered with a protective mulch of bark or gravel.

Advantages: Lightweight and easy to cut Don’t fray along cut edges Very porous, allowing water to reach plant roots

Disadvantages: Cheaper versions do not last long They can ruck into folds where soil accumulates and weeds grow Tougher versions, such as Plantex, are expensive

*Woven materials: These are sheets of woven plastic strands for use as temporary cover, or for the long-term on beds, borders and paths.

Advantages: Available in different grades, varying in toughness, weight and durability Do not need covering with mulch, although mulch may improve their appearance
Disadvantages: Heavier in weight than spun materials Cut edges can fray

Plastic sheeting: Choose black sheeting to suppress weeds for short periods, or in areas of the garden where appearance doesn’t matter.

Advantages: Cheap Easy to cut with a knife or scissors

Disadvantages: Impermeable to water, so the ground can dry out underneath, and rain will puddle on the surface Creating holes in the surface will allow water in, but can provide an opportunity for weeds to grow