We are lucky here in the Midwest to be able to enjoy spring and summer bulbs alike. We plant spring bulbs in the fall and summer bulbs in the spring. We let spring bulbs overwinter in our garden beds and dig up summer bulbs to overwinter indoors.
Our spring bulbs need a cold treatment to trigger them into growing and blooming each spring. That is why if you are going to "force" spring bulbs indoors, they first must be left in the cold or kept in a refrigerator for a period of weeks before you plant them into pots to force or you can pot them up and then store the pots and all. Spring bulbs can begin to bloom just as or after the snow begins to leave the landscape and others will bloom in early April into May.
Summer bulbs are not winter hardy so that is why we dig and store them over the winter. Summer bulbs need to be kept in a spot where they will not freeze, but not warm either as this can prompt them to grow while in storage. One of the challenges is monitoring those summer bulbs in the early spring while in storage, as they will begin to sprout and grow before you really want them to! Move them to a cooler location to slow them down and remember to store them cooler the next time.
Spring bulbs can be planted anytime from now on and up until the time you cannot dig in your flower garden or landscape beds. The earlier you do get them planted, the more time the bulbs will have to establish themselves before the really cold weather. If you dug up and dried your own bulbs or have purchased them recently, go ahead and get them in the ground.
A good rule to follow for planting depth is to set them in the ground 2-3 times their diameter. Small early spring bulbs are planted relatively shallow and the larger bulbs like daffodil and tulip several inches below the surface. Bulb suppliers will have more specific planting instructions on the bag for review prior to planting.
A similar pattern happens with the summer bulbs planted in the spring. In general, we call many plants summer bulbs, yet they can have corms or rhizomes too. Think Canna, Gladiolas, Caladium, Calla lily and others. Bulbs can be protected from our wildlife that seem to know we just planted them and stop by for an easy meal, especially if you are planting an entire bed. After you put enough dirt to hold the settle the bulbs in place, but before you completely fill the bed, lay a piece of chicken wire down to cover the bulbs and finish the backfill. Wildlife will hit the wire and give up for an easier meal.
About the author: Richard Hentschel’s expertise extends across several subject areas with specialties in lawn care, fruit tree production, woody ornamentals, and home and community gardening. During his 45-year career in horticulture and agriculture, Hentschel became a well-known and respected expert for commercial and homeowner audiences, industry organizations, and media. He retired from University of Illinois Extension in April 2022 with nearly 30 years of service as a Horticulture Specialist and Educator in northern Illinois.