How to force hyacinths for Christmas

A practical demonstration from a UK nursery on how to pot and chill hyacinth bulbs for Christmas flowering. This guide draws on "Preparing hyacinths for Christmas", from Burncoose Nurseries in Cornwall. It covers choosing prepared bulbs, potting them correctly, and the timing for chilling and bringing them indoors.

1. Buy prepared or treated bulbs

This is the single most important thing to get right. Standard hyacinth bulbs will not flower at Christmas - you need "prepared" or "treated" bulbs, which have been given an artificial cold period by the grower to trigger early flowering. They are sold at garden centres and online from September onwards, usually labelled clearly as prepared or Christmas-flowering.

Common varieties for forcing include Jan Bos (deep red), Delft Blue, and Carnegie (white). All of these have a strong fragrance. Buy the largest bulbs you can find - a big bulb means a bigger, stronger flower spike.

2. Choose your container

Bulb bowls, terracotta pots, ceramic dishes, and even glass hyacinth vases all work well. The container does not need drainage holes if you are careful about watering, though a pot with holes and a saucer is more forgiving.

For a good display, plant three or five bulbs together rather than one on its own. They look better in odd numbers and will support each other as they grow.

3. Plant the bulbs

Use bulb fibre or a general-purpose compost. Fill the container about halfway, then sit the bulbs on the compost with their tips pointing upwards. Space them close together but not quite touching. Pack more compost around them, leaving just the top third of each bulb poking out above the surface.

Water lightly so the compost is just damp, not wet. Soggy compost at this stage will rot the base of the bulbs before they have a chance to root.

4. Give them a cold, dark period

Hyacinths need around eight to ten weeks in cool, dark conditions to develop their roots and trigger flower formation. The target temperature is around 5-9°C - cold but not freezing. A shed, unheated garage, or spare room that stays cool works well. If the winter is mild, the back of the fridge works in a pinch, though you need to keep them away from fruit (the ethylene gas from apples and pears can damage the bulbs).

Cover the pots with a paper bag or black bin bag to keep them in the dark. Check them every couple of weeks and water very lightly if the compost has dried right out - you want it just barely moist.

5. Bring them into the warmth at the right moment

After eight to ten weeks, the shoots should be around 5cm tall and pale yellow-green. This is the point to bring them indoors. For Christmas flowering, that means moving them inside around the 1st to 7th of December.

Start them somewhere cool and fairly dim for the first week - a hallway or cool bedroom - so they green up gradually. Then move them to a warm, bright spot. Too much heat too quickly can cause the flower spike to develop inside the leaves rather than growing up cleanly above them.

6. Water and care while flowering

Keep the compost moist but not waterlogged. The warmer and brighter the spot, the faster they will come into flower, but also the quicker they will go over. A cool room at around 15-18°C will give you a longer display than a warm sitting room at 22°C. Avoid placing them near a radiator or in direct sunlight.

Tall flower spikes sometimes need a little support - a short bamboo cane and a loop of soft string does the job without looking too conspicuous.

After flowering

Forced bulbs are unlikely to flower as well indoors again the following year. You can plant them out into the garden in spring - they often recover and flower as normal outdoor bulbs after a season or two. Or just compost them and buy fresh prepared bulbs next autumn.

When to call a handyman

Planting hyacinths is one for doing yourself - there is nothing here that needs a handyman. That said, if you have larger garden tasks to sort before winter, such as raised beds to build, fencing to repair, or a greenhouse to put up, Richard is available for that kind of work across Sandwich and East Kent.