Winter flowering crocus are more dainty than their large flowering Dutch cousins. My mother always had a bowl of these on the kitchen windowsill, much admired for their beauty and loved by the cat. They are grown outdoors in the open or a cold frame and simply moved inside once they start to make flowers. They are equally effective in selected spots in the garden.
The larger and later flowering (March) Dutch crocus are one of the most impactful of all the early flowering bulbs. Their colour glows in the spring sunshine when they open but, they remain closed during bad weather and at night, protecting their nectar for visiting bees and butterflies on sunny days.
They have many uses; planted in a border as spring bedding, planted in small groups in a herbaceous border or rockery adding early colour, planted in pots and containers both for outdoor and indoor use, and using the large flowering ‘Dutch’ crocus in grass.
They are very easy to grow but do need a sunny aspect, for like many bulbs they need summer warmth to remain free flowering. Plant from the end of September until late November. They will increase rapidly year on year. Every four to five years check for signs of overcrowding, typically reduced flowers or stunted growth. The best time to divide crocus is in September, if you can find the corms. The easier alternative is to wait until after they have finished flowering and their foliage has begun to die back, usually in late spring or early summer.
A few other pointers to bear in mind:-
• Plant the corms 5-7.5cm (2-3 inches) deep. Planting too deep is often the cause of crocus failing to flower and not readily increasing
.
• Crocus like a well-drained sandy loam and an open sunny aspect, they need summer warmth to remain free flowering. Plant on a layer of sand if the soil is heavy and not well drained.
• Add potash when planting and they will thrive.
• In grass roll back a turf, add a layer of loam compost and potash, place the corms and replace the turf, treading down to remove any air pockets.
