A fresh start: It's time to work out what's really possible in your garden and get planting

Rules are what you look for when you first start to garden: rules about humus and hardening off, intercropping and insects, pricking out and pollination. But as you go on, you understand that garden rules exist only to be broken. Your own ability to tune in to the ebb and flow of the seasons and to notice your plants' reactions to those changes will, in the end, be much more useful than any other source of knowledge. And even then, you will still have disasters. Learn to be sanguine. There is always another spring. But it's useful to spend time this month and next thinking about the year ahead, what you might grow, how you might grow it, generally sizing up the options.

If you want to grow fruit and vegetables, the options will depend entirely on the space available. You can produce excellent crops on a balcony or a roof garden, but you would not expect to build an asparagus bed there. If all you have is a kitchen windowsill, then you may become the world's expert on basil or rocket, but you are unlikely to be able to pull a decent carrot. Finding the right place for the right plant is the secret of success in gardening and it is as true for fruit and vegetables as it is for flowers. Some vegetables will grow in partial shade. Some demand sun. Some want lashings of food and drink. Others will spin a crop out of little more than thin air. Think of these things when you are planning what to grow.

Once you grasp hold of the notion that fruit and vegetables do not necessarily have to be grown in purdah, separate from the rest of the plants in the garden, all kinds of possibilities for using them arise. Instead of planting a rose on a sheltered wall, you may put a pear there instead and train its malleable branches into a fan. Instead of raising a dividing screen of larchlap fencing, you may think of planting a loganberry or a tayberry and training it on parallel wires to make an extremely productive partition.

Use structures such as tunnels to give you more growing space and plant vines and kiwi fruit among the midsummer roses. You might think of bringing an artichoke into the back of the flower border to give height and architectural substance to flowers that are lacking in both. You might edge a path with crinkly-leaved parsley, perhaps planting it alternately with groups of chubby violas. One of the best foreground groups in the late Christopher Lloyd's Long Border at Great Dixter was once a bright patch of parsley mixed with the rich blue pimpernel flowers of Anagallis monellii.

You might experiment with using lettuces as foliage plants among bright marigolds and zinnias. Lettuce, now, is frilled and flounced and may be red or bronze as well as 40 shades of green. You may decide to fill the hanging basket with tumbling bush tomatoes. All these things are possible, and look beautiful as well as providing you with food. There is no pleasure to equal that of picking your own supper, on a summer evening. The pleasure is more muted when you are trying to hack a parsnip out of frozen ground in winter, but even that may have a masochistic charm. Divert yourself by thinking of the mouthwatering parsnip purée that will be your reward.

When sizing up the options, think hardest about the features that will be the most permanent. These are likely to be fruit trees. Could you fit an apple onto the lawn? The answer is probably yes, but your life will be made easier if you choose a half-standard with at least 1.2m (4ft) of clear stem before the branches start to arch out. This will grow into a fine tree, will be easy to mow under, to sling a hammock from and be infinitely more beautiful to look at than a squat bush reined in by a dwarfing rootstock.

Could you make better use of paths in the garden by turning one or more of them into a curving tunnel dripping with grapes from a vine (if you are a romantic) or runner beans and purple podded climbing French beans (if you take a more pragmatic view)? Again, the answer is probably yes. Tunnels for the vine can be permanent structures – hoops of iron joined by cross pieces – or temporary. For the runner beans you could make a simple tunnel from hazel poles bent and lashed together over the path and joined at the sides with horizontal poles. Then you could have borders of courgettes and alliums bobbing around under the beans.

Now's the time to cast an eye over your beds and borders and think where you might do better this year. Occasional drama is what you want, to wake up the sleepy hordes of geraniums and well-bred campanulas. Vegetables can provide that drama as easily as flowers. The best borders, as gardeners are told a thousand times, are those that include plenty of good foliage. Only the slightest shift in focus is needed before you reach for a scarlet-stemmed chard instead of a bergenia, plant a globe artichoke rather than an acanthus, or fill a gap with the supremely decorative endive 'Variegata di Castelfranco' rather than a hosta. What could be a more fitting companion for a rich red verbena than the elegant drooping flags of a leek, especially the French blue-leaved type, 'Bleu de Solaise'?

Think about bringing in flowers to mix with the vegetables, too. Allow nasturtiums to sprawl among the sweetcorn. Use pot marigolds to paint lines of orange between green strips of spinach and carrot. Scatter seed of the Californian poppy, eschscholzia, to spring up in beds of cut-and-come-again salad crops such as mizuna or saladini.

The fun of deciding what to grow has to come after sizing up the options. You may not have enough space to do all that you want to do. You may not have enough sunny sites to be able to grow your chosen crops. Taste matters, too. However longingly you may dream up visions of purple Verbena bonariensis waving above the blue-green flags of a leek bed, it will be a waste of space to grow them if you have a family that is resolutely anti-leek. With some vegetables, such as tomatoes, there is no such thing as too much. Tomatoes are decorative, they can be trained to grow in vertical space, and they make eye-catching centrepieces for vegetable beds. They crop well on balconies, too, where you could make a miniature Villandry with a grow-bag planted with tomatoes trained on canes, surrounded by well-watered pots of salad vegetables: cut-and-come-again lettuces, endive, rocket, mustard and cress.

If the way things look is more important to you than the process of producing food, you may be tempted to choose vegetables entirely on appearance. This is the mistake that supermarkets make and it would be a waste of your time to grow things that did not taste gorgeous, too. If you choose carefully, you can have the best of both worlds, bounty and beauty combined in yellow courgettes and tiger-striped tomatoes, red-stemmed chard and purple-podded beans. Rich, rampant profusion is the thing to aim for. Whichever option you choose, be generous.

Anna Pavord's new book, 'The Curious Gardener' (Bloomsbury, £20), a collection of her columns for The Independent, can be ordered at a special price, incl p&p, by calling Independent Books Direct on 08700 798 897