By Susan Albert
Summer-flowering bulbs, corms, rhizomes, and tubers bring a wide variety of colors and shapes to Oklahoma and Texas gardens. Staples, such as canna, lilies, dahlias, caladiums, callas, gladiolas, and tuberous begonias are traditional favorites. But others, including tuberose, Peruvian daffodil, and crinum lily, are fun to try too.
Most bulbs require well-drained soil and sun, except tuberous begonia and caladium, which thrive in shade. And depending on how far south you live, you may need to lift the bulbs in fall. Dahlias, for example, need to be lifted north of Zone 7, and tuberose is hardy only to Zone 8.
Here are popular summer bulbs:
- Lily (Lilium spp.) — Large blooms, some varieties fragrant, make true lilies stand out in a summer border. You may need to stake tall varieties. The raspberry and white ‘Stargazer’ (pictured above) and pure white ‘Casa Blanca’ (right) are two popular choices.
- Caladium (Caladium bicolor) — Large, heart-shape leaves grown for their bold coloration, usually in red, pink, and green. Plant when the ground has warmed to 65°F. Hardy in Zones 8–10. Otherwise, treat as an annual or lift, and store tubers in fall. Plants in containers may be moved indoors for winter.
- Calla (Zantedeschia aethiopica) — From the jack-in-the-pulpit family, the elegant calla sports unusual blooms. Some varieties also have speckled foliage. Ideal planted in rain gardens or bogs. Treat as an annual or lift, and store rhizomes in the fall north of Zone 8.
- Canna (Canna spp.) — With its colorful blooms and large, sometimes purple or variegated leaves, canna gives your summer garden a tropical appearance. For optimum flowering, provide plenty of water and sufficient fertilizer. Lift and store tubers north of Zone 7, or treat as an annual.
- Crinum lilies (Crinum spp.) — Huge bulbs form bulblets below ground. After a drenching rain, horn-shape red to pink to white blooms arise in clusters. A low-maintenance bulb, suitable for bogs or dry areas, it’s hardy in Zones 6 to 10.
- Dahlia (Dahlia spp.) — Dahlias bloom from midsummer to fall, and tubers can be lifted and stored about two weeks after a hard frost north of Zone 7, or treated as an annual. Colors include red, pink, lavender, purple, orange, yellow, and white. Provide some afternoon shade in Southern gardens. Pinch tops of plants for bushier growth, and deadhead to keep dahlias blooming till frost. Good for cutting.
- Gladiolus (Gladiolus spp.) — In tall or dwarf form, upright spikes full of large, colorful flowers bring a nostalgic look. Blooms in midsummer. Excellent cut flowers. Lift and store corms before frost.
- Peruvian daffodil (Hymenocallis festalis) — An unusual white, daffodillike flower, with spiderlike tendrils. Blooms in early summer. Treat as an annual above Zone 8, or lift and store bulbs in fall.
- Tuberose (Polyanthes tuberosa ‘The Pearl’) — Grasslike foliage gives way to spikes of waxy white single or double flowers, prized for their wonderful perfumed scent. Lift and store the clumps of small bulbs in fall north of Zone 8.
No matter which bulbs you choose, you will be rewarded with eye-catching, easy-to-care-for plants all summer.