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.

Good to know: Curcuma is thermophilic, does not tolerate low temperatures.

African Blood Lily (Scadoxus)

Scadoxus, (skuh-DOX-us) blooms before the leaves are formed. I was lucky on my first attempt to grow it in a squat 12-inch Azalea pot, having overplanted them with Oxalis (shamrock) bulbs. After several weeks, when the Oxalis‘Iron Cross’ had all but covered the pot, up popped the weirdest, but coolest plant in my garden. The chubby green stalk reached only eight inches before it formed a bud that gradually unfurled into an electric coral, softball-sized globe.

You can bet I wanted to repeat it the following year. Unfortunately, the bulbs rotted when I tried to store them for winter. But the following year, I found a leafy plant labeled Scadoxus and watched for a flower to form. It turns out, the bulb has to be of a certain age before it is mature enough to bloom. If you see a pot with a label that says Scadoxus, make sure it holds the husky stalk that tells you it will bloom this season.

I will be sure to make another attempt at overwintering any Scadoxus I plan

Good to know: You can find Scadoxus under the name Haemanthus.

Gloriosa (not really a lily)

It’s not in the lily family, but Gloriosa is referred to as Gloriosa lily, or flame lily. This tropical tuber is in the same family as autumn crocus. All parts of Gloriosa are poisonous. Even so, people in Asia and Africa use its seeds, tubers and roots in traditional medicine. Be careful when handling the plant. Its exotic flowers are reason enough to try it in your garden. Another plant that prefers a very warm environment, Gloriosa is a vining plant with shiny, bright green leaves that wear tendrils at their tips. The vine looks better with some type of support for the tendrils to cling to. I used a wire frame inserted into a large planter on wheels, bringing the complex floral show up to the eye for close inspection.

Gloriosa is quick to bloom. From planting in late April, mine started blooming in early July. Its flowers dangled from thin stems, their swept-back petals heading in the opposite direction from its stamens. When the weather got cold, I cut back its growth and wheeled the entire pot into our unheated mudroom off the garage, unprotected from blasts of cold every time the door was opened. Surprisingly, it came back and bloomed again the following year.

Good to know: Gloriosa is the national flower of Zimbabwe.

Agapanthus (African Lily)

Agapanthus grow like weeds in California and any other place with a sunny, somewhat dry climate. But they also can be grown with a little extra care even in the Midwest. Agapanthus grow from a rhizome that forms an army of fleshy, unrelenting roots. Its roots often force their way to the soil surface. According to The Color Encyclopedia of Cape Bulbs, by John Manning, Peter Goldblatt and Dee Snijman, the species A. praecox is one of the most commonly grown ornamentals in the world.

Today, hybridizers are busily creating and introducing new varieties with bi-color flowers, variegated leaves, blooms in a deeper blue, and increased hardiness. I had great success purchasing an unnamed variety that was incredibly potbound, its roots pushing upward onto the surface. It bloomed in the same pot all summer long.

Agapanthus prefers its roots cozied up into tight spaces, which can be arranged by planting it in a pot. In one of the best short videos on the topic, BBC’s Gardeners’ World producer Monty Don shows how to plant Agapanthus in a pot.

Southern Living Plant Collection has introduced a few new varieties of Agapanthus, which should be available at several garden centers.

Good to know: The name Agapanthus is from the Greek “agape,” meaning love and “anthos,” for flower; so it could be referred to as the flower of love.

Of course, these tropical bulbs, tubers or rhizomes won’t survive a really cold winter. To save them for the following year, they’ll need to overwinter indoors.

            MAIL-ORDER BULB SOURCES

As with many types of plants, it’s best to go to the specialists to find the best selection of bulbs. Other sources include local plant societies.

• Brent and Becky’s Bulbs: Gloucester, VA 23061, Phone: 877-661-2852
• Easy to Grow Bulbs, Oceanside, CA
• Edens Blooms: Thatcher, AZ 85552, help@edensblooms.com
• Glasshouse Works: Stewart, OH 45778-0097, Phone: 740-662-2142,
• Longfield Gardens: Lakewood, NJ 08701, Phone: 855-534-2733
• Old House Gardens: Ann Arbor, MI 48103-4957, (734) 995-1486
• Plant Delights Nursery: Raleigh, NC
• Telos Rare Bulbs: Ferndale, CA  95536