Grow something tropical: Bromeliads are worth learning about

You’ve seen them almost every time you’ve gone to the garden center or grocery, yet you may not have known them by their collective family name. Bromeliads are some of our most unusual tropical plants. Yet, as common as they’ve become, we still have a lot to learn about this colorful group of durable house and patio plants.

You can learn about how to grow bromeliads by studying their habitats. They’re native to Central and South America. Many of the showier types are from tropical rainforests, where they compete with the vivid colors of orchids, parrots, birds of paradise and other Equatorial icons.

Most of these bromeliads are epiphytes, meaning they grow in the shade or part shade and suspended high in trees. They germinate and grow in organic debris that collects in the crotches of tree limbs and branches. Many have tightly tubular leaf arrangements, and it’s within those "vases" that the plants catch rainfall and falling debris that yields nutrients. The leaves absorb and use the water and nutrients much like roots do for more typical plants. Keep the planting mix moist to support their root systems, but remember to add water into the vases when they begin to empty.

Bromeliad Web sites and plant shows feature hundreds of species and varieties of the epiphytic types. But there are several that make up the majority of what you’ll see in retail nurseries and plant shops.

Aechmeas are bold-leafed plants. The most popular forms have comparatively wide (2- to 3-inch) blue-gray leaves and hot-pink, spear-shaped floral heads. They tend to grow as single plants or small clumps.

Billbergias have thinner leaves and longer, more open floral sprays. They multiply freely, and the clumps must be divided and repotted every year or two.

Neoregelias are absolutely gorgeous. The plants’ colors intensify as they bloom, but they start out either dark-green, bronze-green or variegated. The flowers just add to the show.

Vrieseas are more difficult than the other bromeliads we’ve mentioned. Unfortunately, they’re not very tolerant of indoor conditions. But their floral spikes are so spectacular that they’re commonly sold.

Other different types of bromeliads grow in the arid, foreboding conditions of the Southwest and Mexico. Many have barbed leaves for protection from animals. Some are called "earth stars." Their leaves radiate from the center of the plant resembling flattened stars. Cryptanthus varieties are the most common, but you’ll also see several types of Dyckias. These are often blended into cactus and succulent collections in Texas garden centers.

The terrestrial bromeliads operate differently than the epiphytes. Most are well-suited to full sun. However, they must be grown in well-draining soils, because they’re accustomed to getting by on modest amounts of moisture in their native homes. Use a gravely, porous potting soil. And, since these plants’ leaves don’t form vases, you’ll water them like you do your traditional plants.

There is another novel thing about bromeliads. When a plant blooms, the mother plant will die as new plants, or "pups," are forming alongside it. Once they have begun to develop their own sets of roots, you can sever and pot them individually.

Perhaps the two best-known bromeliads aren’t even grown as houseplants. Improbably, Spanish moss and pineapples are both bromeliads.

For fun, bromeliads (particularly pineapples) can be brought into flower ahead of schedule when they’re exposed to ethylene gas. Commercial growers may bubble the gas into epiphytic plants’ vases, but you can accomplish the same thing with an apple core. Place it within the vase and wrap the plant with several layers of dry-cleaner plastic. Use large rubber bands or electrical tape to make it airtight. As the apple core decays, it will give off ethylene. Keep the plant in bright light but out of direct sunlight for several weeks. You can open the plastic and put a second apple core in 10 or 15 days later for a fresh supply of gas. You’ll know within five or six weeks if this technique will work. If the plant fails to flower, you can wait awhile and try again. Obviously, your costs are minimal.