Catasetum

Light should be strong. Plants grow best with light levels of 32,250-64,500 lumens (3,000 to 6,000 foot-candles). If using artificial lights, they should be on for 12 to 16 hours a day.

• In the greenhouse, 40% to 70% shade will provide sufficient light levels.
• In the home, they should be in a window that gets >4 hours of direct sun a day.

More light should be provided during dormancy, as in nature, the plants become more exposed to direct sun.

Temperature affects this group of orchids more so than others. Like many tropical plants, Catasetum-type plants will grow faster with more heat. Do not let Catasetum-type plants get cooler than 65F (18.3C), or you may arrest their growth and trigger dormancy.

During the growing period, day temperatures of 80F to 100F (26.6C-37.7C) and night temperatures of 65F-75F (18.3C-23.8C) are beneficial. After growths mature, temperatures can be reduced to day temperatures of 70F to 85F.

Water is a critical factor for the production of large pseudobulbs that result in best flowering. A great quantity of water must be stored by the plant in a relatively short growing season. Water heavily as new leaves are forming. As the pseudobulb matures, gradually reduce watering frequency. Leaves will yellow and drop. At this time, watering should be stopped completely until new growth begins. Water Iightly to rehydrate the pseudobulbs if shriveled severely.

Humidity should be 40 to 60 percent. This can be provided in the home by placing the plants on trays of gravel, only partially filled with water so that the plants do not sit in the water. Air should always be moving around the plants to prevent fungal or bacterial disease, especially if high humidity or cool temperatures exist. In the greenhouse, the humidity is best increased by use of a humidifier while cooling the air.

Fertilize and water regularly to produce strong pseudobulbs. Use a high nitrogen formulation (such as 30-10-10) while plants are in active growth, slowly tapering off as pseudobulbs forms. A blossom-booster formulation (such as 10-30-20) should be used in the autumn, except for plants that normally bloom in the spring. Frequent applications of a dilute concentrations of fertilizer are more effective than occasional applications of strong concentrations.

Potting should be timed to coincide with the initiation of new growth, usually in the spring. New roots will be produced quickly at that time, and plants will experience minimal setbacks. These plants have vigorous root systems and require a rich, moist potting medium during the growing season. Many greenhouse growers bare root their plants during the resting period to ensure dryness. Indoor growers do not need to bare root for dormancy, as room temperatures are cool enough, and the spritzing/very light waterings are okay. Fine-grade orchid bark mix and sphagnum media are common for smaller pots; medium-grade media are used only in larger pots. Sphagnum moss is used successfully for plants in many areas, as it provides tremendous water and fertilizer-holding capacities. Some plants can be grown on slabs of treefern or other material, which makes it easier to keep them dry during dormancy; however, it is harder to keep them moist while growing. When well-grown, these orchids can be divided down to one mature pseudobulb and will then flower on the next mature growth.

Catasetum-type plants hail from tropical seasonal climates – there is typically a wet, hot summer followed by a cooler (usually room temperature), dry winter. To minimize water loss during the winter, these plants will drop their leaves. New growths with leaves will come about in the spring, with increasing light. Plants should not be watered until the new growth has roots that are 3–5 inches (7.5–12.5 cm) long. By this time, the developing growth will be rapidly expanding and plants should not dry out much until it’s time for them to go into dormancy. Some species/hybrids will tell you when they are going dormant; others will need to be pushed into dormancy with the reduction of water and temperature at the end of the growing season. Plants should be leafless and dormant by January in the Northern Hemisphere.

Spider mites are a common pest of these orchids when in leaf. Control spider mites by keeping humidity high or spraying with recommended miticides.

Further information can be found on the Catasetum genus page.

Best orchid care practices are also provided for watering, repotting, and fertilizer types. There are also detailed discussions of growing orchids indoors, outdoors, or in greenhouses.

For more information on genus name changes, see Taxonomy.