BASIC CULTURAL INFORMATION FOR CRYPTANTHUS BROMELIADS
Commonly know as 'Earth Stars' because of their low, spreading rosettes of 6 to 20 leaves that hug the ground, these plants are members of the Bromeliad family, and related to the pineapple. The word 'cryptanthus ' actually comes from the Greek words cryptos, "hidden", and anthos, "flower". Cryptanthus, true terrestrials (growing in the earth), come in a variety of shapes, colors, and patterns, and are adaptable to a wide range of growing conditions. There are approximately 50 terrestrial species of Cryptanthus that usually have serrated leaves with wavy margins from 3 to 6 inches in length, but can be up to 12 inches. They can have sharp zigzag patterns and are usually strongly banded or frosted with gray, white, or bronze and many have pink to red background color. The white, light green or pink flowers bloom in the center and from between the leaves.
LIGHT: Bright, diffused light (not direct sun) is needed to bring out maximum color in most Cryptanthus, which means 55% to 75% shade in sunny climates. Too little light and the wonderful colors and patterns will fail to develop; too much light causes bleaching of color and sunburn. Patio areas lit by morning or afternoon sun and office settings with florescent lighting are good locations.
TEMPERATURE: Optimum growth occurs between 60 and 85 degrees, but Cryptanthus tolerate a wide range of temperatures from just above freezing to over 100 degrees. At the higher temperatures, be sure the plants are protected from the scorching effects of direct sunlight, there is adequate humidity, and the potting mix is not allowed to dry out. In temperate climates, they can be grown as bedding plants and ground cover.
WATER: Keep the potting medium moist at all times and never allow it to dry out. If kept indoors, mist the foliage to provide humid conditions. Cryptanthus suffer and don't usually recover if they dry out for extended periods, and they are sensitive toward stagnating wetness. They adapt well to the warmth and humidity of terrariums.
AIR: All bromeliads like good air circulation.
FEEDING: A slow-release fertilizer combined in the potting mix is recommended, with additional feeding using a dilute solution (1/4 tsp. per gallon of water) of a high quality, water-soluble fertilizer such as DYNA-GRO. Beware of copper and boron that are toxic to bromeliads. Your fertilizer should have none or no more than trace amounts of these micro-nutrients.
PROPAGATION: In most bromeliad species, the plant you see blooming now will not bloom again, but begins a reproductive cycle that should produce multiple plants that should mature within approximately one growing season. The 'pups' will draw nourishment from the mother as she gradually declines. When the offset is one-fourth the parent's size detach with a slight tug and pot no deeper than the base of the first leaf. Don't worry if there are no roots on the 'pup'.
POTTING: Cryptanthus should always be grown as potted plants since they are true terrestrials and do not absorb water or nutrients through their leaves and are not suitable for mounting. They develop a strong root system equal to the size of the plant, so do not underpot. A 5" to 6" pot will allow the roots plenty of room and plastic pots help conserve moisture. They prefer a medium that retains more water than other bromeliads, but it still must drain rapidly. Use a loose, porous medium rich in peat moss or other organic material. Commercial African Violet mixes will work.