Storing bulbs for winter—How to store garden bulbs until spring planting
September 17, 2019
There are times (admittedly rare) when a memory-lapse is delightful. I’m happily surprised each spring when bulbs that I’ve forgotten I planted make their way above ground to bloom, reminding me that this was the plan all along! Not so delightful are the times when I forget to take care—as in forgetting to dig up and store bulbs that need protection from our harsh winter months. (I still feel guilty about the fate met by the most beautiful canna lilies gifted to me years ago.)
Since then I’ve kept a garden calendar of to-dos that ensures that tasks such bulb digging and storing get accomplished before the ground freezes around them. This year, I’ve gone a step further to learn the best way to store the bulbs. Could I do better than tossing them in paper bags in the basement?
Which bulbs to pull in the fall
Not all bulbs need to be dug up seasonally. Tulips, grape hyacinths, crocus and daffodils—happy, easy flowers—hunker down until the ground thaws and the sun coaxes them out again in the spring. Remarkable, right? In fact, these bulbs need that burst of cold every year in order to bloom.
BTW, even bulbs that survive cold winters need to be dug every so often to prevent overcrowding. But we’ll talk about that in another, more general bulb-care post.
When you purchase and plant bulbs, always check to see if they need to be pulled and stored over the winter. More tender bulbs that won’t survive cold winter temps include:
When to dig up the bulbs
I like to dig the bulbs after the first frost but before the first hard freeze. It’s easier on the bulbs, I think, because they haven’t had a chance to be damaged by the freeze. (And I know it’s easier on me). Watch the leaves—they’ll tell you when the party’s over.
If you’ve missed that mark, you can still dig them after a hard freeze, but don’t wait much longer. You don’t want the bulbs to freeze.
How to dig bulbs
In a word, carefully. It’s a terrible feeling to pierce a flower bulb with a garden fork as if it were a baby potato on your plate. The best way to avoid damage while digging bulbs is to dig up the entire area around and underneath the bulbs with a fork or spade, overturning the soil and lifting the bulbs and their roots by hand.
How to prep bulbs for storage
Once they’re all above ground, brush the heavy dirt off the bulbs, along with any dead materials, which may cause the bulb to rot in storage. Some folks like to gently rinse the bulbs, but I’m reluctant to introduce water at this point, so I just brush them off. (I use a clean paintbrush.)
Whether or not you rinse them, be sure to let them dry well before storing. One good option is to place them out of direct sun and wind on a screen for a couple of days. Don’t let them freeze!
Cut off the stems and leaves. Some experts recommend treating the bulbs with a fungicide at this point, though I’ve never found this necessary.
Choose a (non-plastic) box or container or paper bags and some “breathable” storage material such as peat moss, straw, vermiculite, shredded newspaper, sawdust, or a mixture of sand and moss. I’ve heard of people using foam (non-dissolving) peanuts, too. I guess it beats throwing those away, and they would provide a tidy, dry home for the bulbs, with air circulation to boot.
Label your bulbs by writing on the containers or attaching tie-on labels to each. I’ve read that you can write directly on the bulbs, too, though I’ve never tried this.
Put a layer of your storage material in the bottom of the box or bag, then layer the bulbs in the box, roots down (as you would plant them in the soil) taking care to not let them touch each other. Cover the tops with the storage medium (moss, etc.).
Where to store bulbs
Place the container in a cool, dry place where the bulbs won’t freeze and where rodents can’t get them. (Too warm and they’ll want to sprout, too cold and you’ll kill them.) So not in a garage that freezes or a pantry in the sunlight or near a furnace vent, for example.)
When it comes to temperatures, you can get pretty exacting (dahlias prefer temps between 35 and 45 degrees, for example, while calla lilies like temps between 60 and 70 degrees). I just aim for temperatures around 50 degrees or so. And I definitely keep it below 70 degrees.
Through the winter, visit your bulbs and remove anything that looks rotten or moldy (bulbs or storage medium). Give each bulb a little squeeze, and if it feels mushy toss it. On the other hand, if things are looking much too dry (the bulbs are shrinking/appear wrinkled), lightly mist the storage material with water.
Once the last winter frost happens (hurray!) take them out of storage and plant them outdoors again. If you find sprouts on your bulbs (because they got a little toasty), don’t break them off. Simply handle them carefully and plant as is. If you like, this is a good time to divide your bulbs, too.
What are you digging up this fall? What’s your favorite storage spot for bulbs?