Growing Green: light-bulb moments
When you hear the word “bulb,” what is the first flower you think of: tulip, daffodil, crocus, snowdrop or other fall-planted bulb?
Can you name your favorite summer bulb? These include begonia, caladium, canna, dahlias, gladiola, lilies of many varieties, oxalis, and many more.
Bulbs is a term used loosely to include corms, tubers, tuberous roots, rhizomes, and true bulbs. Bulbs are grouped broadly into spring-flowering (January through May) and summer-flowering (June through September) plants.
Bulbs can be planted in the fall or late spring. Those planted in the fall are generally hardy bulbs, while those planted in the spring are typically tender bulbs, such as dahlias and tuberous begonias.
Growing conditions for summer bulbs are different from spring bulbs in that a summer bulb needs full sunshine, with some exceptions, decent soil, and excellent drainage. If the soil is clay and drainage is poor, the bulbs will rot. If the three conditions are met, it will most certainly give your summer bulbs a good growing habitat.
To get off to a good start, the bulbs need consistently warm soil. The planting date should always be after the last frost and the temperature preferably between 50 and 60 degrees.
Bulbs should be planted two-and-a-half to three times deeper than their height. Always consult planting recommendations supplied with the bulbs by the grower.
The key to maintaining perennial bulbs, whether they bloom in the spring or mid-summer, is to allow their foliage to ripen. Avoid any temptation to cut back foliage until it becomes limp and yellow.
The ripening bulb foliage provides food and nutrients to the bulb in advance of the next growing season. Cutting the foliage too early deprives the bulb of these nutrients and weakens it. Cut away and compost the foliage after it has yellowed.
Many summer bulbs require winter storage in a cool, dry place after being dug up for the winter. Most of the tender bulbs require 40- to 50-degree temperatures in dry vermiculite or peat moss. Some grown in containers can be moved indoors and left in the pots to overwinter.
A too-warm storage climate dries them out, rendering them not viable the next season. Be sure that air circulates around stored bulbs.
Here are a few tips: Summer bulbs require a great deal of water immediately after planting. The soil in your garden should be continually moist, not wet.
Sprouting is healthy. Plants are anxious to get into the ground again. If the plant has multiple buds, they can be divided at this time with a bud or two for each division.
Maintain a pH level of 6 to 7 to bring out the true color of flower bulbs. Additional fertilizer is not necessary for summer flowering bulbs and tubers.
“Growing Green” is contributed by Lehigh County Extension Office Staff and Master Gardeners. Information: Lehigh County Extension Office, 610-391-9840; Northampton County Extension Office, 610-813-6613.