At its best:
Order plants in March from mail-order suppliers. Bulbs will be delivered bearing roots and leafy shoots.
Prepare the soil well and fork in plenty of compost or well-rotted manure. Plant bulbs as soon as they're delivered so just their green tips sit above soil level.
Firm soil round each bulb and then water thoroughly to settle the soil. Even with leaves these small bulbs are prone to drying out, so continue to water each week if conditions are dry.
Depending on the variety and when you plant them, your snowflakes may flower in their first year of planting. Allow the bulb foliage die down naturally in summer, providing the bulbs with the energy they need to flower the following year.