The last two years my tulips have come up in the spring stunted and not opening properly. Those two Vancouver British Columbia winters have been milder than usual. I think the tulips have suffered from not being cold enough over the winter. Would it help to prepare them before planting by putting them in the crisper in my fridge for a number of weeks? If lack of enough cold is not the answer, what might it be and what can I do about it?
I think you are probably right that the mild winters are causing the issues with your tulips. Most tulips require 12-14 weeks of consistent chilling at temperatures just above freezing – 40-50F or 5-10C. Temperatures above this level could cause the bulbs to break their dormancy too early resulting in stunted growth and bloom.
To avoid this problem, you’ll need to replicate these conditions. Store your bulbs in a paper bag in your crisper for the required amount of time. Time the storage such that at the end of the storage period the tulips can go directly into the ground or your containers as soon as your soil is typically workable. Avoid storing the bulbs close to fresh fruit as the ethylene gas released from the ripening fruit can reduce bloom.
Your local garden centre may also have pre-chilled bulbs available in the early spring.
As you are in Vancouver, you might want to check with the Vancouver Master Gardeners to see how gardeners in your local area are responding to these milder conditions. You can reach the Vancouver MG’s Plant Information Line at 604-257-8662 or by email at firstname.lastname@example.org.