Hello,

There are a number of requirements that must be met to successfully keep the bulbs over winter when out of the ground. When they were potted, the containers must have drainage holes. Then, pots should have been watered at the time of planting. Spring flowering bulbs, including crocus, need a chill period 40 F degrees or lower for 12-16 weeks in order to bloom. Alliums do not need a chill period to bloom.

The concern with having them outdoors in pots is- are they deep enough and surrounded by enough soil to keep them from being killed by freeze/thaw?

Usually potted bulbs are sunk in trenches to keep them evenly cold, then brought out after 12 weeks or more, and then either forced to bloom indoors or set out to bloom in spring.

Other ways to store potted bulbs is in a cold garage, or clustered in a group in the garden with mulch, straw bales, etc piled around and over them.( though this runs the risk of squirrels etc finding them! Chicken wire weighed down over them would help)

If a refrigerator is available the whole pots can be stored there-soil should just barely be damp. Alliums like dry soil so be sure soil is dry in those pots. Too wet and the bulbs might begin to sprout. If this happens there is no choice but to bring them out into bright light and let them bloom. Bulbs that are forced to bloom indoors rarely transplant well into the garden-except daffodils, which some gardeners report do fine.

So, you should be following the basics of ‘forcing bulbs’ but keeping them cold enough so that they will bloom in spring. Set them into the ground with as much of the soil-ball as will stick as soon as the soil can be worked this spring. There is no guarantee the bulbs have survived but it is worth a try. Good luck and thanks for using our service.

Hello,

Thank you for your prompt reply! A few follow-up questions.

You said that "usually potted bulbs are sunk in trenches to keep them evenly cold." What do you mean by "trenches"? What size pots would this be for?

You said that storing the whole pots in the refrigerator is a possibility.
Does that mean that you would not suggest digging the bulbs back out of the soil, letting them dry a bit, and keeping them in paper bags or a small cardboard box in the refrigerator?
If this is in fact an option, how long should they dry?
And should something like dry sphagnum peat moss, wood shavings, or shredded paper be added?

If the bulbs end up in pots in the garage (inside), or even outside, should they be watered at all to make sure that the soil stays slightly moist, for the Crocuses at least? 
Should the Allium pots just be kept dry?

Thanks again.

Hello,

Trenches are dug into the soil long enough to accommodate all the pots and about 12 inches or deeper, depending on the size of the pots. You want about 10 inches of soil over the tops. Trenches are then loosely back filled with soil or mulch. (See the references, below)

Removing bulbs now—- it depends on if the bulbs are all completely dormant— dig a few of each type and see if they put out any roots. If they did, replant and leave them in their pots. If they are still not sprouted on top or on the bottom root area, you may be able to put them in damp moss, in paper bags/boxes and place in the frig. Check them once a month to see that crocuses are moist. I would moisten the alliums every other time you moisten the crocus. 

Moisture is a matter of balance-you don’t want dry shriveled bulbs and you dont want moldy or sprouted bulbs. If you decide to dig and dry them, a day or two of air drying should do it, unless the bulbs were very wet to begin with. Stored bulbs will try to sprout after their cold period has been reached. So, in early spring they may sprout no matter how they were stored.

Here are some references for you on these topics so you have something for next season, if needed. 

I hope this works for you. 

References—-

https://www.extension.umn.edu/garden/yard-garden/houseplants/forcing-bulbs-for-indoor-beauty-in-winter/

http://msue.anr.msu.edu/news/forcing_spring_bulbs_to_bloom_indoors