Yet another letter this week from a gardener who has stopped buying peat. But this one was different.

He says that he buys growing bags instead and boasts that they're full of wonderful peat, plus an enriching mixture of nutrients, and they're cheaper.

And once you've used them as growing bags they are still useful, as seed and potting compost or to spread over the garden as mulch.

I refuse, as usual, to get embroiled in the controversy over whether or not people should use peat just as I won't argue about the use of garden chemicals and other contentious issues.

What I do say, though, is that growing bags are one of the great inventions of the age.

Not all of them, of course, are filled with peat; you can buy bags made up of peat substitute.

Growing bags have revolutionised tomato-growing for amateurs and professionals alike.

There are a few rules, naturally. The most important is to follow the directions which are usually printed on the bag itself.

It's particularly important to follow the instructions carefully to avoid excessive dryness or over-wetting, both of which can be fatal.

Generally plants are grown from seed in pots or trays in the greenhouse or on a windowsill and the tender subjects should be put into the moistened growing compost in the bags as soon as the risk of frost is over.

The bag can then be placed anywhere where space is limited, such as with a concrete or paved backyard, patio, or balcony. With hardy crops, of course, there's no need to wait until after the last frost.

Other specialist bags have been developed especially for salads and vegetables including even marrows and courgettes.

You can't beat a good growing bag, no matter what's inside it.

By Jim Roberts