Expert: Kenneth Joergensen - 4/7/2004

Question
So if she puts them in the fridge until around  August, should they be planted then or wait? Our plnting zone is zone 4?
Thank You!
---------------------
Followup To
Question -
Hello,
I have a friend who ordered tulip bulbs quite a few months ago and never got them planted.  Is it possible for them to bloom yet if I got them planted now (Begining of April)  I know the ones that I currently have planted are already starting to come up.
Erin
Answer -
Tulips require a vernalization period (cooling period) to flower. If you plant them now, they will start to grow, but because they have not had their vernatilization requirements fulfilled, they will not bloom.

What she should do, is to put the bag of tulips in the fridge for 15-18 weeks (longer is ok). After they have been stored cool, they can be moved to a planting site outdoors. Hopefully they will bloom then.

If she stores tulips in the fridge, do not put fresh fruit or cut flowers in the fridge. the ethylene released can sterilize the bulbs.

She can also keep them in the fridge until next fall, and plant them directly in the soil at the proper planting time for her area. Hopefully they will still be ok. Just make sure the soil has cooled before planting to avoid premature growth.

Answer
Normally, to give the proper cooling period, they need to be planted in soil (or potting mix) and put in the fridge for 18 months.

Southern gardeners will put the bulbs in the fridge without planting for 10-12 weeks and then planting in december (the coldest period of the season) and then they will grow and flower. The reason they do this, is that the cool soil of december (even in warm season areas) combined with pre-cooling without being planting is enough to induce flowering.

However, putting bulbs in the fridge without planting in soil first, and keeping them for 15-18 weeks is not guaranteed to flower because the soil is probably too warm in august.

My recommendation would be to either put them in a ventilated bag in the fridge (onion bag) until next fall and plant after soil temperatures have cooled. they should then flower next spring. Just note that bulbs are somewhat fuzzy about this, and may not flower anwyay if kept for this long period of time, so no guarantees.

If you had written me in January and told me that she forgot to plant them, I would have advised you to dig a hole outdoors when ever she could and plant even if the soil was frozen -- or plant in pots and put in a cool unheated garage of sheed for the winter. However, starting the process now where temperatures are soon going up is not ideal.