In a hot, humid summer, the perky plants of May are languishing by late July. That’s where tropical bulbs come in and save the day. Sure, there are dozens of annual flowers that go the distance during the hottest days of August, but there is always room for a fresh collection of flowers to set a new tone in the late summer garden. Don’t forget to fertilize! Here are four that are grown for their flowers — ginger (Curcuma), African lily (Agapanthus), blood lily (Scadoxus) and gloriosa lily (Gloriosa)—to will reward you from late summer through early fall.
Because most of these tender bulbs come from warm climates, they require a long, hot summer to bloom. Some benefit from an early start indoors, while others get going pretty quickly as soon as the days warm up.
Ornamental Ginger (Curcuma)
I discovered this ginger last August when my neighbor (and partner in a serious plant obsession) brought home a gorgeous potted plant. My plant-seeking buddy is likely to visit garden centers throughout the months of summer to see what is available. It’s a good idea, as many nurseries continue to refresh their stock after the popular springtime buying phase, (usually April through June) when people purchase their annuals for the summer.
The plant, labeled Curcuma (KUR-kyoo-muh), is a member of the ginger family, and originates in areas of monsoons, where there is a very wet and then a dry period. During the dry periods, the plant goes into dormancy until the next rainy season.
Curcuma grows from a rhizome, somewhat like those pudgy, edible spice fingers you find at the supermarket. The spice we call ginger comes from Zingiber officinale. Another well-known spice, turmeric, comes from the species, Curcuma longa.
Curcuma varieties grown for their showy flowers are often called “tulip gingers,” or “Siam tulips,” and are popular with the cut flower industry, their strong stems holding blooms displayed well above the leaves. Many varieties do well in either full sun or part shade.
According to Tim Chapman, Gingerwood Nursery, Curcuma can be forced to grow and bloom earlier than normal, but that process is usually carried out by professionals who are readying a crop for a holiday. “Soil temperature is the primary stimulant for breaking dormancy,” he said.
I told Tim I’d planned to use a heat mat to induce the growth of two varieties of Curcuma I’d ordered. Gingerwood Nursery is in southern Louisiana, so he hasn’t had much need for heat mats, but was working on experimenting with a variety of methods to induce growth with heat.