How to Chill Bulbs
Some bulbs require chilling before you plant them for best performance and flowering and others do not. If you look at where they come from, and when they flower you can get a good indication. Bulbs that come from areas with cold winters, and that flower in spring are the main candidates for chilling, however most home gardeners in Australia tend not to chill bulbs unless they live in warm climates.
So for those spring flowering bulbs that require chilling, they need about 5 weeks at around 5 C and they need to be dry, under no circumstances let them freeze. So for Tulips, Hyacinths and a few others try this method.
- Dig the bulbs in December to January
- Give them a cool dry rest until Autumn
- Chill for 5 – 6 weeks before planting
- Try to plant them by mid June
What happens if you do not chill bulbs and do not dig them ?
Firstly Tulips require a dry summer when they are dormant, if you leave them in the garden try not to water the area they are planted in. Watering in summer can lead to rot. If you do not chill them, the success of flowering will depend on the climate, in cooler to cold winters they will get a natural chill, however in Australia this is not always the case, they can lose their floriferousness, or produce poorer smaller flowers.
Chilling Bulbs for forcing
If you have ever wondered about those displays of tulips at garden shows in autumn, its simple they have been forced. Chilling bulbs in the refrigerator for forcing is a different process.
Bulbs are chilled or ‘forced’ to flower at different times of the year by giving them a ‘false winter’. This involves chilling them for 4 – 5 weeks and then planting them out in a warmer position. The bulbs think they have had winter and spring has come, so they flower.
Bulbs should NOT be chilled in a refrigerator where food is stored