Store where it's cool as possible without freezing.
Your bulbs have been through a long trip since they were comfortably in the ground.
Back in Holland, they were expertly grown, fed, and cared for. Then, they were dug, handled carefully, and then packaged for their journey from Holland to your garden.
The time for this out-of-ground experience for your bulbs can be quite long. After all, with almost all summer-flowering bulbs, you have to wait until frosts are finished. That means in cold places like Vermont, you really can't plant them safely until late May.
So what do you do to store them properly while you're waiting for that lovely spring day when you put them back into the ground.
Basic Storage Know-How
First of all, bulbs need to be kept dry, of course. But equally important, they need to be kept cool to keep them from sprouting before you plant them. How cool? Obviously, you'll need to keep them within a distinct temperature range. But don't worry; it's easy.
Not too hot, not too cold, just right. As for cold, it couldn't be simpler--make sure your bulbs don't freeze. That means if you're still having freezing nights in your area, under 32 degrees F, you can't put them in an unheated garage or garden shed. As for heat, you must keep them away from the furnace, out of bright sunlight, and out of any other place that can be a "hot spot" in your home. Choose a place that is dry, dark and cool. If you have a day basement, and things down there don't freeze on cold nights, that's probably the best place. Lots people find the perfect places in unheated closets that stay cool or utility rooms where the household heat is weak.
Be ready when your bulbs arrive. If you're going to have to hold your bulbs for some time, try to be ready before they arrive. Of course, there's no need to panic. No harm will be done if the bulbs lie around the house for a day or two. But if you're storing them for over a week, you need a special place.
Bulbs must be stored below 45 degrees F. If you find a good dry place where the temperature stays between 35 and 45, that's the perfect spot. But to some degree, it depends on the type of bulbs you're storing. All need cool storage, but some are more demanding than others.
Here are some rules of thumb (also in chart at top):
Lilies must be stored below 45 degrees, or they will probably sprout before planting. (If they do, treat the sprouts gingerly. If you break them off, your bulbs are ruined.
Dahlias and Gladiolus can stand a bit higher temperatures. They should be stored anywhere between 40 and about 62 degrees, the lower the better.
Canna Lilies like to be stored around 50 degrees, and should never dry out.
Calla Lilies and Elephant Ears like it warmer, between 60 and 70 degrees.
Bareroot Perennials need to be as cool as possible without freezing, to prevent any sprouting.