VAL BOURNE says crocus has responded to the sunniest February on record

I have just been to a Crocus Day held at RHS Wisley. The first speaker, John Grimshaw, voiced the opinion that crocus should be just as popular as snowdrops. John is a well-known galanthophile and co-author of the snowdrop monograph. But then most galanthophiles (or snowdrop lovers) recognise that gardens need both, and therefore usually adore both.

Interestingly, the snowdrops' appearance is mainly governed by temperature. So in mild winters, the snowdrop appears early, however dull and sunless, the year. But the crocus is spurred into life by light levels. We have just had the sunniest February on record, and every crocus has responded by opening widely. This year's display is a corker.

One of our other speakers was Janis Ruksans, a bulb grower from Latvia and author of a wonderful book, called Buried Treasure, published by Timber Press. Janis has travelled all over the world collecting crocus. However, his own stock are nursery-grown, and he specialises in crocus, corydalis, and tulips among others. Most of his slides show him in high mountainous places in late spring, because lots of crocus are high alpines, found on the snow line. There are 80 species of crocus, but many need a long summer dormancy and a cold, dry winter, and they are alpine house, or bulb frame plants. However, some can be accommodated in the garden setting, given open sun, well-drained soil, and possibly some protection against mice, who love to eat them at every stage.

Some crocus spread by seed, and Crocus tommasinianus is the slender, usually purple crocus, seen spreading into lawns. The Crocus King, E.A. Bowles (1865-1954), tells us it was named by Dean Herbert in honour of his botanist friend Signor Tommasini of Trieste. The species, found naturally on the shores of the Adriatic, parts of Dalmatia, Bosnia, and Serbia, is described as "a smart new umbrella", compared with the thicker buds of Crocus vernus, which are more of the gamp' style by Bowles.

Crocus tommasinianus has the advantage of being one of the earliest to flower. It may be too invasive for some, but it is happy to cross with other crocus species, and can produce lots of hybrids in a spangle of differing colours. Plant it close to forms of Crocus chrysanthus, less-bred forms of Crocus vernus and Crocus biflorus, and you can get variable seedlings courtesy of the bumble bees.

The forms of the yellow-throated Crocus sieberi are always very early. The form tricolor' has lilac flowers, with a large yellow throat, edged on white. The second earliest are bred from Crocus chysanthus, possibly crossed with C. biflorus. The goblets are small, and they form into tight-knit clusters of flower, rather than a sprinkling, so they are good at the front of borders. Jeanine' is primrose-yellow, with purple flames, and Ladykiller' is white, with purple markings. Blue Pearl' is a soft silver-blue, and Cream Beauty' a soft butter-yellow.

The really bright colours tend to be from Dutch crocus bred from C. vernus, an Alpine meadow species. Some people dislike them for being too brash. There's a rich-purple, called Flower Record'. Remembrance' is a silver-purple. Jeanne d'Arc' is a pristine white, and Yellow Mammoth' is a blinding egg-yolk yellow.

Don't forget the Gardeners' Question Time in aid of Brideswell Organic Gardens on Wednesday at 7.45pm at Exeter Hall, Kidlington. 01993 868445 or 01869 350155.