Control of weeds

Weeds are controlled by hand weeding, hoeing, slashing, smothering or using herbicides. Often a combination of methods is needed.

Some weeds are very difficult to eradicate by hand weeding or with chemicals as they grow from bulbs, rhizomes or roots deep in the soil, which allow the plant to readily regrow. Soils often contain large numbers of weed seeds, which regrow after plants are removed.

As a general guide, remove weeds then quickly cover bare soils with mulch to reduce regeneration. Especially remove weeds before flowering to prevent seeding and spreading.

Where weeds grow from an underground bulb or other plant part, try to remove all parts of the weed to reduce regeneration. If this is not possible (for example oxalis and onion weed, which are two highly persistent weeds) use other control techniques such as smothering weedy soils with layers of weed mat, newspaper or cardboard and mulch. Leave the covering for up to a year to ensure the weeds have been killed. Where soils are very weedy, it may be necessary to grow desirable plants in containers, while the weeds are smothered or treated. Creating raised garden beds may be an option for smothering some weeds.

Various herbicides are available that help kill weeds in home gardens. Some are non-selective and translocated meaning they are absorbed by plant cells and will kill any plant they come in contact with (both weeds and desirable plants). Others are selective and translocated to target specific types of weeds (such as broadleaf weeds in lawns, clovers, mosses and algae), while still allowing grasses to grow.

Organic herbicides such as EarthCare Organic WeedKiller spray are based on naturally occurring oils (such as those derived from plants). They work by burning and killing the above ground plant parts (such as leaves) and are non-selected contact sprays.

Earthcare Organic Weedkiller is an organic contact herbicide containing pelargonic (nonanoic) acid, which causes the weeds to quickly dehydrate and collapse. Visible results are seen as browning and wilting, usually within hours of application.

Always read the instructions before applying herbicides for example avoid spraying before rain and keep products away from watercourses and non-target plants.

Disposing of weeds

When disposing of weeds, don’t put weed seeds or plant parts that can regenerate into compost heaps or into areas where they can regenerate (such as dumping weeds into bush or waste land).

Problem weeds removed from the garden can also be made inactive by soaking them in water for several days or weeks before they are deep buried.