By forcing some spring bulbs in autumn, you can coax them into flower early, giving you an indoor display of beautiful blooms right through winter.
Some bulbs, like amaryllis (Hippeastrum) and daffodils (Narcissus), need just a short spell in a shady spot to kick-start growth. Find out how to force amaryllis bulbs for Christmas. Bulbs hailing from colder climates, such as hyacinth and muscari, need to feel winter’s chill. This usually means a stint in a cool (maximum 7°C), dark place such as a fridge, cellar or unheated shed.
Some bulbs need a longer spell than others, so it’s a good idea to stagger your planting times and use a range of bulbs to lengthen the display.
As the ‘winter’ period ends, the bulbs can be moved to a warm, bright (avoid direct sunlight) spot, to flower. Don’t let the compost dry out or become waterlogged, and keep plants away from radiators and other heat sources.
Discover how to force nine different bulbs, below.
Prepared paperwhite narcissi
‘Prepared’ bulbs such as Narcissus ‘Paperwhite Ziva’, take nine to 11 weeks to bloom. Place in a cool, shady room for three to four weeks, then bring into light and warmth. Chill ordinary narcissi (daffodils) at 5-7°C for nine weeks, then treat as prepared bulbs.
Alliums such as Allium cowanii are more challenging, but worth a try. Use early varieties and start in autumn, potted up in gritty compost in the garden. Keep them there for 10 weeks, then move to the fridge for 10 weeks, before moving to their final cool, bright spot indoors.
Tulips take longer to force but are worth the wait. Cover the bulbs with bulb compost and place in a cold, shady, north-facing area to chill, for 14-20 weeks, before moving to a light, warm spot indoors to flower. Short-stemmed varieties work best.
Easy to force, crocus bulbs require a chilling period of 8-10 weeks. After this, check the roots are well-developed before positioning in a bright room out of direct sunlight to green up and flower.
Iris reticulata bulbs will take 13-14 weeks to bloom. Just grow the bulbs in a bulb compost with a little added grit in the cold and dark for 10 weeks, then move to a light, warm place indoors.
Grape hyacinth (Muscari)
Grape hyacinths will also take a short while to bloom. Plant as many as will fit in small terracotta pots without touching, their roots engaged with moist bulb compost. Chill for 10 weeks, then move out to the warmth.
Snake’s head fritillary
Snake’s head fritillaries need a more moist compost – just don’t let them get waterlogged. The bulbs will need a chilling period of around 15 weeks before they can be moved to their final position to flower.
For both standard and prepared hyacinths, plant bulbs to half their depth in bulb fibre, mulch with grit then water. Chill prepared bulbs for eight to 10 weeks, or 11-14 if unprepared, then move to a warm, light location. Or force the bulbs in hyacinth vases.
Unlike most other bulbs, those of amaryllis don’t require chilling prior to flowering. Instead, place the base of the bulb in lukewarm water for two hours, Then grow in a vase with water and pebbles or compost. Find out how to force amaryllis bulbs for Christmas.