Urban gardener: Weed or wonder?

May is a time when the full reality of what needs to be done in the vegetable garden hits you: sowing seeds, tending seedlings, watering, protecting plants from late frosts and stopping slugs and snails from hijacking all your efforts. Then there are weeds. These have already had a head-start on our vegetables. However, a recent addition to my book collection is about to change their status from nuisance to opportunity – because this year some of them will be eaten. Cooking Weeds by Vivien Weise (£9.99, Prospect Books) is about just that, using nature to its full potential. I'm already set to try some of Weise's recipes, from Ground Elder Layered Pancakes to Daisy Ginger Soup.

Foraging is nothing new, but what is astonishing is the nutritional value of some weeds compared with the vegetables we normally grow. Weeds such as dandelion, daisy and fat hen contain on average twice as many minerals as many of our most popular leaf vegetables, twice as much vitamin A (with the exception of the carrot, whose content of this vitamin is frankly obscene) and almost four times as much protein and vitamin C.

Weise's book states that of around 150,000 edible plant species in the world, only 150 are regularly found in supermarkets and that an average household probably uses no more than 30 species. Of course, it's understandable why some people are suspicious of eating weeds, but you don't have to sign up to an SAS survival course to get started. Most non-gardeners ought to be able to identify a nettle, daisy or dandelion, all of which are edible. Beyond that, you could join a local foraging group to find out what you can eat in your area.

Even if you know your weeds it's worth taking a few simple precautions. Chomping on a sprig of hairy bitter cress only to be told that it had just been sprayed with glyphosate was an undignified moment in front of a client. If you have pets then choose weeds from your garden that are out of reach of cocked legs, and always wash your vegetation first. On no account eat something that you are unsure about. Fresh weeds will always be best so pick them when they are young and tender. This is important for Ranunculus ficaria (Lesser Celandine): it's toxic once flowers appear.

Ground elder figures in Weise's recipes for pancakes, cheese soufflé and potato spread. Nettles are also used (rissoles) and these have always been a favourite of ours to make soup, their rich mineral content making Popeye's staple look pathetic by comparison. The only other weed we have used in the kitchen is fat hen (Chenopodium album), again rich in minerals with an extremely high potassium content. Weise makes gazpacho from it; we use it as another spinach substitute, but haven't got round to using the seeds, which can be crushed and made into bread flour. Save for the flower stalk and seed, all parts of dandelion (Taraxacum officinale – meaning "official remedy for disorders") can be eaten, the flower buds and leaves raw in salads, the roots cooked and eaten like any other root vegetable or roasted and then ground to make a coffee substitute. The leaves are best harvested in late spring, ideally before the flowers become too bitter. The only one I'm wary of is hogweed. The book says its shoots can be eaten like broccoli, but only refers to it as hogweed with no botanical name to tell it apart from some 200 varieties, some of which are toxic. Heracleum mantegazzianum, for example, can cause severe blisters. While it was disappointing not to find recipes for Couch Grass Chowder or Convolvulus Crepes (both weeds having the upper hand at our allotment), Bistort Bolognese or Ribwort Plantain Omelette may well find their way on to our plates this spring.

Cleve West wins Chelsea gold: Cleve's Bupa garden was awarded a gold medal at this year's Chelsea Flower Show, the second time he has won the prize. Next week: what the future holds for his winning design