By Evelyn Alemanni
If you like drama in your garden, then you’ll want to plant some summer bulbs. Summer bulbs include caladiums, dahlias, gladiolas, colocasias, and alocasias. Because colocasias and alocasias need heat, humidity, and lots of water, they tend to suffer when grown in Southern California, so I’ve omitted them from this article.
Summer bulbs are sometimes called tender bulbs because they are not winter hardy in cold climates. In such cases, gardeners either treat them as disposable annuals or dig them up and store them till replanting in spring. Here in Southern California, unless you live in an area that has hard freezes, you can leave the bulbs in the ground and expect them to return year after year.
You can find easy-to-grow caladiums, gladiolas, and dahlias in a wide variety of colors and sizes; they add sparkle and interest to any garden. Technically none of these are bulbs. Caladiums and dahlias grow from tubers, while gladiolas grow from corms.
Many people think caladiums need to be grown in moist, shady areas. In fact in Florida, where most are produced, they grow in large fields in full sun. Another caladium myth is they need lots of water. I water mine briefly once a week. During the past two years I’ve had the opportunity to try quite a few varieties, and discovered they grow best in pots filled with rich potting mix. The results were much better than growing them in the garden. They also make spectacular houseplants, as long as you remember that they die back after a few months. But as with most bulbs, they return the following year.
Good to Know: Caladiums grown in full sun are more colorful than those grown in shade.
One of the nicest things about caladiums is that they last long in bouquets. The colorful foliage can even substitute for flowers in the garden and in bouquets. In my book, Caladium Bouquets, you find lots of ideas for using caladium foliage in decorative settings.
Dahlias are available in many forms – short and tall varieties, as well as flower forms that include pom-poms, single and double flowers, cactus-flower types, and the so-called “dinner plate” dahlias, named for their enormous flowers.
Good to Know: An easy way to get lots of dahlia plants is to start them from seed. The seedlings form tubers over the summer that overwinter and rebloom the following year. Another way to get more dahlia plants is to plant the tubers early in spring, then take cuttings 4 to 6 inches long, and root them in a mix of vermiculite and perlite.
Dahlias are happiest in full sun, planted in well-drained soil, and receiving average water. They love fertilizer! Dahlias perform well in the garden and in containers.
Good to Know: Before planting dahlias in containers, be sure to check their mature sizes, so you can match the size of the pots to the dahlias’ eventual width and height.
Like caladiums, dahlias are beautiful in bouquets.
Gladiolas are tender bulbs that thrive in full sun. Most species grow tall—up to 5 feet! There are short varieties as well. Gladiolas make wonderful cut flowers; you should cut them when the lowest buds begin to show color. The stems continue to grow after being cut and placed in a vase of water; to prevent this, snap off the uppermost buds.
Good to Know: It’s important to plant “glad” bulbs in early spring to prevent thrip infestations—they can cause leaves and flowers to become shriveled and distorted. Soaking the corms in Lysol (4 teaspoons/gallon of water) up to 6 hours before planting can deter thrips, but be sure to plant the glads immediately after soaking.
Once planted, gladiolas grow fast and most likely require staking to keep stems straight. Some gardeners like to plant glads close together, so they can support each other.
Good to Know: for a continuing floral display, plant gladiolus bulbs every two weeks.
Planting caladiums, dahlias, and gladiolas brings lots of delightful color to your summer garden, and gives you flowers for gorgeous bouquets.