Child's play: Anna Pavord on the delights and dangers of letting the kids get stuck into the garden

Anything you now read about gardening with children is so hemmed around with warnings about the sharpness of tools and the poisonous nature of plants that there is scarcely room left to celebrate the good things about it. The chief danger is unfamiliarity. In the Caribbean, children of four handle cutlasses with ease and dexterity. They've always been around them. They know what they can do.

So I'm not going to waste space telling you how to prevent a child gnawing on an aconite root. Most children are sensible enough to reject something so hideously bitter. Parents, though, may find that the way their children approach gardening is a good indicator of future character. It was certainly like that with our three girls.

The youngest gardened only for profit, growing vast quantities of mustard and cress, radishes, lettuces and tomatoes. These, keenly priced, were set out on a table by the back gate together with posies of flowers. A pipe led down through the palings into a bucket our side of the gate. A heavily embellished notice pinned to the table instructed passers-by to "Put Munny in Pipe". To my astonishment and her delight, several did. Any produce remaining at the end of the day was sold to me, at a small discount.

The middle child made a weed garden, choosing a good piece of land in a south facing border, so as to give the weeds the best possible chance in life. To this sunny, well-fed plot, she brought all the different weeds she could find in the garden, carefully transplanting them and nourishing them with special elixirs of her own making. Making the mixtures - pounding up dandelion petals with rain water from the butt, garnished with a sprinkling of parsley or sage - was an important part of the process.

As gardening lost its charm, she transferred her attentions to other underdogs, joining Amnesty International, becoming, temporarily, a vegetarian, and introducing words like radical, ethnocentric and alternative lifestyle into family conversation.

The eldest child, as is so often the fate of eldest children, did everything that she should. She tended her plot conscientiously, put a bird bath in the middle of it, edged it with shells, weeded fanatically, dead-headed, even got her strawberries to fruit when my own patch was a complete wash-out. Order from chaos seemed to be her motive. At a time when most of the rest of the garden was a wilderness, her small square was a haven.

By the age of 12, only a few children will still be interested in gardening and then usually in one specific kind of plant, cacti perhaps, or carnivorous plants. So the initial span may be short, but it can teach important lessons about respect for plants and their needs. That leads to a wider respect for the way that the world is put together. It's fatal, of course, for any parent to preach in this way. The messages that come through gardening are subliminal.

As with all things to do with children, gardening will not grab them just because some other person thinks it should. If you are interested yourself, your children, while they are small and much with you, will likely also want to be involved. For a while it seems they only want to stick their trowels in precisely the same spot as your own. This is the most frustrating stage for both parties. All you can do is hang on for the good times and, in a calm voice, explain why they should not pull up young plants to see how the roots are growing.

The more interesting stage comes later, round about four or five years old, when children can cope with their own plots. Size and situation are important. Although you may grit your teeth when handing it over, a child's plot needs to be on good soil and in an open situation. If it is stuck in a corner under a privet hedge, discouragement is inevitable. If it is too small, there will not be enough scope for experiment. If too big, it will become a chore rather than a pleasure. A space with room for expansion is ideal.

Edging, marking the boundaries, seems to be important to a child, so you need plenty of bits and pieces to hand for this task: pebbles, slivers of wood, scallop shells if you live in that sort of nouvelle cuisine home, broken brick if you don't. If you are called on for advice, distinguish clearly between matters of fact and matters of taste. In the case of sowing seed, certain principles must be grasped and followed. In the matter of planting orange French marigolds among purple pansies, children must follow their own noses and do what delights them.

Tools should be real tools, even though a trowel may look like a miner's shovel in the hands of a four-year-old. It is important they feel you are treating their garden seriously. Dolls' house tools that buckle at their first encounter with a stone do not give this impression. And don't make them wear gloves. It's good to be in direct skin-to-skin contact with the plants. They won't be planting euphorbias after all.

Pansies are a likelier proposition, being both appealing and of strong constitution. This matters. A child's garden is no place for a sickly plant. Choose those that can survive being over- or under-watered and handled with the dexterity of a prize fighter with gloves on.

Fast-growing plants are a boon, as the long drawn out nature of many gardening processes is what children find difficult to grasp. Sunflowers are excellent if you have room. Sweet peas are also satisfying, as they can be started in pots inside and planted out against a wigwam of canes when they have outgrown the kitchen windowsill.

The mixtures of annual flowers specially packaged for children were not a success with our mob. The pictures on the packets encouraged expectations rosier than reality. Broadcasting seed straight on to the ground is not a sure enough method of success for children. Buy plants to give the bulk of the flowers and for the rest, stick to big seeds, such as nasturtium that can be handled easily, or grown singly in pots inside and transplanted later.

Food goes down well in children's gardens. Growing it, that is. Tomatoes are slow, but rate high in the amount of titivating that can go on around them, nipping off side shoots, adding more ties to the stake. As they go up rather than out, they are especially valuable where space is limited.

Mustard and cress is quick and you can sow the seed in shapes scratched in the earth with a stick. Initials work well. Megalomaniacs may enjoy growing monster marrows, but you need space. One plant will take up about four square feet. There is a pleasantly mythical quality about marrows and pumpkins; you can carve your initials on a marrow too, and watch them get bigger as the vegetable grows.

Delfland, who send out organically raised young vegetable plants for gardeners and allotment holders, have put together a special selection for a child to grow. It includes 'Little Gem' lettuce, French beans, pumpkins, sweetcorn, strawberry plants and 'Tumbler' tomatoes - 42 plants for 11.50 plus postage and packing. There is important pride and self esteem to be got in putting your own vegetables on the table in front of your family. And it's cheaper than psychotherapy.

There is another side to gardening with children, of course. This has to do with tulips falling in a flail of airgun pellets, of footballs through greenhouse windows and a mudslide where you once remembered a lawn. The most cataclysmic gardening event of my own childhood was the experiment my brother carried out with home-made gunpowder and a cocoa tin. It blew a crater worthy of the Western Front in the lawn, but he passed his chemistry exam with flying colours.

Delfland Nurseries are at Benwick Road, Doddington, March, Cambs PE15 0TU, 01354 740553, www.delfland.co.uk