Spring Planting (Summer Blooming)
When is it time to plant summer-flowering bulbs outdoors?
Plant summer-flowering bulbs once the soil has warmed to 60º F (15.5º C) or about the time you plant your tomatoes. Tender bulbs love warm weather, and include such beauties as dahlias, begonias, cannas, gloriosa lilies, caladium, elephant ears and others. Tender bulbs can languish or die where cold air and cold soil inhibit growth, so wait until the nippy nights and frosty morns have passed.
Can summer-flowering bulbs be forced or fooled into blooming "out of season" like tulips?
Not really. Summer-flowering bulbs don't undergo the same internal chemical process that spring-flowering bulbs do whereby they develop leaves and flowers after a cold (winter) period. So artificially shifting the seasons on summer-flowering bulbs won't trick them into flowering. In addition, the flowering of these bulbs depends on many other factors such as local temperature, daylight hours, soil condition and soil temperature.
Can I plant summer bulbs in containers
Absolutely! Containers and summer bulbs go perfectly together. Simply dig, drop and be done with planting, then move the pots into prime viewing spots for bloom. To plant, fill the pot 1/4 to 1/3 deep with soil, arrange the bulbs at the proper depth, cover with soil up to 1 inch (2.5 cm) below the top of the pot (to allow room for mulch and watering). Be sure your container has drainage holes in the bottom; bulbs don't survive in waterlogged soil.
Are summer-flowering bulbs winter hardy?
Most summer-flowering bulbs originate from sub-tropical regions of southern Africa and Asia or South America. They usually aren't winter hardy and prefer warm temperatures and humid conditions. Check the recommended climate zone for each bulb type to see if it's winter hardy in your area.
Is it possible to store summer-flowering bulbs over the winter?
It helps to know the temperature and moisture conditions for each bulb species, since they can vary. If your climate is tender enough for your particular bulbs then, yes, they can be stored over the winter in the garden. Be sure to cover them well before winter starts. In many cases, the plant will bloom better the next year (Agapanthus, amaryllis belladonna, crinum, canna and lily). For bulbs grown in containers, it's usually best to keep the bulbs in the pot and place it under proper growing/storage conditions in the home or in storage.