Can you plant seeds from shop-bought produce? Yes, but ...

Most fruits contain seeds, and some plants culinarily regarded as vegetables - including tomatoes, cucumbers and peppers - are botanically fruits because they contain seeds. When you buy them at a supermarket or greengrocer's, can you use their seeds to grow them in your garden?

"Yes, but there's a high risk you won't get anything that tastes good," says Christine Scherer, horticultural technician at the Bavarian Garden Academy in Germany.

The reason, she explains, is that F1 hybrid (first filial generation) seeds are very often used in commercial fruit and vegetable cultivation. They're the result of "cross-breeding different varieties to produce especially uniform fruit and stable yields."

The generation (F2) produced from seeds from an F1 hybrid may or may not retain the traits of the parent, however, and may even be inedible - which can be frustrating, Scherer says.

What about planting seeds from organic fruit and vegetables? "They're often grown from hybrid seeds too," she points out.

If you buy produce at a farm shop though, you could ask the grower whether the seeds they use are open-pollinated, ie not hybrids. If so, you can sow the seeds of the plants grown from them.

Or you could simply buy open-pollinated seeds and continue to save and sow the seeds of the plants they produce. In the case of tomatoes, for instance, Scherer recommends saving the seeds from the first harvest to minimize foreign pollen contamination.

Nevertheless, it's normal for the tomato variety's traits to change over time. So Scherer says you should take note of the tomatoes' flavour and consistency, and compare them with those in the first harvest. If the tomatoes keep getting softer, you might want to buy a new batch of seeds.

You're also likely to be disappointed if you plant seeds from shop-bought fruit, Scherer warns. Commercially cultivated fruit is the result of grafting, ie combining a young shoot or bud from a desired variety with a rootstock. The outcome of planting a seed from one of these fruits is uncertain.

"If you simply plant an apple seed from a supermarket apple, you'll have to wait many years until it bears fruit," Scherer says. "And you may end up only with crab apples."