Friday, January 16, 2009

Greenhouse and Landscape - Consider Bromeliads for Small Volume Containers

I heard a good talk on containers yesterday. There are many combinations that can be used to make dramatic impacts with containers. However, one limitation often is the rooting volume of the container. You may want to consider bromeliads in this case. The following is more information.

Few families in the plant kingdom surpass bromeliads with their wide variation in size, shape, and foliage color. Many bromeliads adapt to summer growing conditions and can be used in container plantings.

Bromeliads are in the pineapple family (Bromeliaceae), a family native to the American Tropics. Two widely known members of this family are pineapple (Ananas comosus) and Spanish moss (Tillandsia usneoides).

The majority of bromeliads are epiphytes. In their native habitats, they attach by special root structures to trunks and branches of trees and derive their moisture and nutrients from the air and rain. Some are called saxicolous because they attach themselves to rocks, while the rest are terrestrial and grow in the ground as most plants do. Within the same genus there are sometimes tree-dwelling, ground-dwelling, and rock-dwelling species. In fact, epiphytic and terrestrial bromeliads can often thrive equally well if forced to switch places and life styles. It is this ability, in particular, that allows many epiphytic species of bromeliads to be grown in pots like most other plants. Because their roots are only for support, larger bromeliads can be grown in smaller volume containers successfully compared to other plants that derive their nutrients from the potting media.

Plants in the family Bromeliaceae vary widely in shape, size and color. Even species of a single genus often differ drastically in appearance. Most bromeliads cultivated for interior use, however, are alike: without stems and with a central flower spike and strap-shaped, leathery, arching leaves arranged in a rosette.

Most species are grown primarily for their colorful foliage and exotic shapes. Variations in foliage are as wide as those in flowering, and leaves may be green, gray, maroon, spotted or striped. Leaves range from grass-like and less than 2 inches long in some tillandsias, to broad and several feet long in billbergias. The upper leaves of many species change color when plants are about to flower. The gray-green, grass-like foliage of Tillandsia ionantha turns pink, and deep purple-blue flowers arise among the pink leaves. Some species of Neoregelia have red tips on the apex of their leaves that resemble fingernails, and are often called "painted fingernail." Inflorescences (the flowering parts of a plant) may arise from the "cup" or be borne within the "cup." The "cup" or the "vase" is a water holding tank or reservoir formed in the center of many bromeliads by a rosette of overlapping leaves. Flowers are often small but colorful; however, the showy portion of the inflorescence is frequently made up of brilliantly colored bracts borne below each flower. Bracts may be separated, large and leaf-like or overlapping, forming dense spikes. Usually, the bright bracts remain on the inflorescence while fruit matures. The combination of highly colored bracts and often contrasting colored fruit, which remains on the plant for several months, adds to the aesthetic value of bromeliads.


Vriesea imperialis, a good large bromeliad for containers. Photo by Forest & Kim Starr (USGS)

Information largely taken from "Bromeliads" by Robert J. Black and Bijan Dehgan, University of Florida, Cooperative Extension.

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