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This is an organic method of eradicating perennial weeds using a combination of plant exhaustion and heat.

1. During the growing season, mow grass and weeds down short. Water and fertilise to keep them actively growing.
2. Cover the whole area of infestation with black plastic. Underneath this stolons produce long, etiolated (long internodal spaces and white/yellow colour) growth.
3. Under the plastic, without sunlight, plants are unable to produce chlorophyll (green pigment). Chlorophyll also protects plants from UV rays. Choosing a hot sunny day, strip off the plastic. Without chlorophyll the plants are unprotected and get sun-burnt, killing them.
4. It may be necessary to repeat the process several times until the forced growth under the black plastic depletes all the plants' energy stored underground.

Black plastic blocks all the sun's rays, whereas clear plastic allows long-wave radiation in and prevents short-wave radiation from coming out. This produces a greenhouse effect, or solarisation which is good, for example, for sterilising potting soils, but is not so effective to get rid of stolon roots.

Tim's method is a very effective way of killing off invading perennial weeds, particularly stolon rooted grasses.

Vinegar contains acetic acid, which stresses out plants exposed to it. You can use regular kitchen vinegar, but it is weak and may take several applications.

Stronger solution of acetic acid can speed the process, but be careful, this irritates skin.

There is a horticultural vinegar that contains 20% acetic acid that may work quicker.

• White Vinegar: 1 gal
• Epsom Salt: 1 C
• Dish-washing liquid: 1/4 C

Citrus oil is a non-selective, post-emergence herbicide that quickly and effectively kills weeds, grasses and broadleaves without causing harm to the environment. The active ingredient d-limonene (citrus oil) naturally strips away the waxy plant cuticle, causing it to dehydrate and die.

This is a sure-fire way to ensure that you have a prolific, fresh crop of weeds as soon as temperature conditions are right! This brings up viable seeds from deep in the soil, and exposes them to the warmth and moisture that they need to prosper!

Then there's the nuclear option–chemical warfare. For me this a last resort. I have used it a couple of times to kill sheep sorrel (in isolated areas), which has nasty rhizomes that will expand for yards beneath the ground in one season. Before your vegetable plants start producing you'll have a big patch of these plants spread out over a large area. OK, so they are edible - I hope you love them if you let them propagate. They can take over a garden.