As digging and pruning are out, VAL BOURNE turns to the catalogues

I always feel in limbo land at this time of the year. You can't dig when it's sopping wet and you shouldn't prune when it's frosty. So the the only thing to do is settle down with an armful of seed catalogues and plan for next year.

First of all, have a careful look at the seeds left over from last year to check the dates. Throw any that are out of date with the possible exception of larger seeds like beans and peas, which seem to last forever. Be very strict about lettuce and parsnips. They have short viability spans. If these seeds are old they probably won't germinate.

I grow at least 300 plants every year here and I have had my share of failures. But last April was so glorious that everything germinated enthusiastically. It's taught me the value of warmth because the daytime greenhouse temperature settled round 70F or 20C and the nights were warm too. So this year I'll wait for spring proper to arrive before I sow anything.

I favour John Innes no 1 soil-based compost rather than peat-based fluffy composts and sometimes I add vermiculite when sowing tender seeds to keep the soil warmer and aid drainage. I also have a thing about sowing seeds in square pots as the corners tend to get soggy and seeds damp off in the square corners. So I always use round 3in pots and I will be washing hundreds very soon.

But my confidence has been shaken by a report in Gardening Which. It tested seeds from 15 well-known suppliers and it concluded that poor germination was usually down to poor quality seed and often had nothing to do with the gardener. British seeds are expensive and they should be of excellent quality. Yet only six suppliers came up to standard.

Rather than name the baddies I will give you the name of the company that supplied the best seeds over all. It was Thompson and Morgan (01473 695225; www.thompson-morgan.com). A total of 83 per cent of their seeds produced healthy plants. This company, based in Ipswich, has an exciting catalogue containing flower and vegetable seeds and I particularly admire their range of AGM vegetables. These are excellent varieties that have been trialled by the Royal Horticultural Society. Lots of varieties of the same crop are judged by experts and the AGM award (sometimes depicted by a trophy logo) is a great indicator of excellence.

The Runner Bean Wisley Magic' shone on the trial ground and it's done well for me, producing high yields. More importantly, the flavour is excellent. The compact courgette Venus' is also first-rate and squeezing in two plants could produce up to 60 courgettes.

But flowers matter too and there is a lovely wine-red cosmos called Antiquity' that I'm dying to grow. Cosmos are easy annuals and they peak in late summer and autumn so you get months of flower. They also cut well. I'm also keen to grow a new annual sea holly called Eryngium leavenworthii. It comes from the American prairies and the silver thimbles and bracts colour up to purple in the autumn, so it's quite different.

I've been hooked since I grew a packet of Ten Week Stocks at the age of seven, so if you know a child order extra packets for them. I suggest nasturtiums, which need to be sown in early May as they are frost-tender, sunflowers or broad beans, which can be sown early spring.