![]() Guzmania benefit from extra potassium and magnesium. Use lower rates of fertilizers (50-100 parts per million nitrogen) with very young plants (two to three months from transplanting liners). After applying liquid feed over young plants, always wash briefly with plain water afterwards. For older plants, use liquid feed at a rate of 100-200 ppm nitrogen depending on whether a constant feed or alternating with plain water is used. If adding supplemental trace elements, avoid high levels of copper, boron, zinc and manganese. High levels of copper such as those in copper-based fungicides are toxic to bromeliads. Greenhouse light levels should be 1,000-2,000 footcandles. If grown under shade cloth, maintain 73-80 percent shade. Optimal temperatures for most bromeliads range from 55°F-85°F. Brief periods down to 45°F usually doesn’t affect growth. Temperatures above 95°F slow or stop growth, as well as increase disease susceptibility. Good ventilation is essential for successful growing of bromeliads. For most varieties, maintain humidity levels between 65-80 percent. If plants are provided good ventilation and grown on benches, diseases are generally not an issue. Pythium can be a problem if the growing medium is kept too moist. Scale and mealybug are the most common insect pests. Most bromeliads can be force into bloom with treatment of ethylene-producing compounds such as Florel (Ethrel). These compounds can be sprayed on a crop to insure salable plants in spike or in color at desired seasons. Plants should flower about two months after treatment. |

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