Planting Containers of Spring Blooming Bulbs
Potting up containers of spring blooming bulbs is a wonderful option for multiple reasons. Foremost, it gives you a way to enjoy an up-close burst of spring, beyond the garden, or in place of one. Planting into pots offers physical ease, compared to planting into the ground and security from critters digging the bulbs up. Planting into containers also allows for creation of easily rearranged displays utilizing multiple containers and richly layered displays within large solo containers. If the bulbs are to be saved once blooming is finished, the pots can be moved to less visible locations, where the foliage can fade naturally as it collects and transfers energy for next year's flowers. Pots of ready-to-flower bulbs also make wonderful gifts.
Containers should be deep enough to accommodate the height of your chosen bulbs, plus 1” of additional soil for each layer of bulbs and 3” for the bottom. Drainage holes are critical to ensure that the bulbs do not rot. A lightweight, all-purpose potting mix, with a bit of bulb fertilizer mixed in, works best. Prior to planting, toss any bulbs that are not firm and solid, as softening indicates rot. Cover the container bottom with potting mix to a depth of 3”, and then settle your bulbs into it at ½” spacing. Top with 1” of potting mix and water to thoroughly soak the potting mix. To layer more than one type of bulb, such as tulips and daffodils; choose varieties that bloom at the same time and place the largest ones in the first layer, top with an inch of potting mix and then add the smaller bulbs in the next layer (but none directly atop another bulb) and finish off with another 1” of potting mix before watering.
Overwintering and Care
Spring flowering bulbs need a cool dark location to simulate the winter conditions they would experience in the garden and thus meet their “chill requirement”. Containers of bulbs in USDA Zone 6 can often survive against a foundation wall, out of the sun. Those in zone 5 or colder should be overwintered in a frost-free, unheated basement, porch or garage. If your zone doesn't get cool enough for spring flowering bulbs' chill requirements, you can utilize a refrigerator. The bulbs need to be in temperatures of 35-40°F for 8-14 weeks. Between weeks 6 to 8 of cold storage, green tips should appear, but do not move the containers outside until garden-planted bulbs in your area are showing growth. Do check the containers for watering during storage. If the potting mix is dry to a depth of 1” water-well, but be sure any excess drains to avoid causing rot.
At the End of the Show
Many bulbs can be saved for reuse, though hybrid Tulips will not put on the same quality of repeat show as species Tulips or Narcissus. Bulbs to be reused still need sun and water, after flowering, in order to rebuild energy reserves. Continue watering until the foliage yellows. When the leaves are brown and dried up, dump the container to retrieve the bulbs and lay them out to dry. Once dry, brush off any soil and trim off dead foliage before storing in a cool dry location until fall planting time.