Cattleya Plant Culture
Cattleya flowers come in almost every size, shape and color. They are one of the most advanced in their breeding and have captured the eye of almost every orchid grower. These were my first orchids and they still are my favorite genus. The wide variety of flower colors and flowering periods keep my green houses blooming in a riot of color for 12 months a year. With a careful selection of 20 to 25 plants a hobbyist can have Cattleyas blooming year round in their collection.
Watering and Fertilizing are related as water carries fertilizer into the root zone. Important for good Cattleya growth is to have their roots dry down between watering. I fertilize with every watering using a weak fertilized solution of 100 PPM nitrogen, this equates to ½ tsp in a gallon of water. In the summer when days are long and warm, the plants are in active growth and photosynthesis is at a high rate I water more. Usually 2 times a week, however during the hottest period I may water 3 times a week. During the cooler months watering once a week is generally satisfactory. Before watering I always check that the potting media has dried out sufficiently. Once a month I leach the pots where I water without fertilizer twice, one hour apart, this reduces any salt build ups.
Light levels, Temperature, and Air Movement. Theseare closely related as light raises temperature and air movement cools it. Cattleyas like light levels of about 2500-3500 foot candles (fc). For optimal growth I suggest growing under 60-65 % shade in winter and 70-75 % shade in summer. This is accomplished by adding a second layer of 30% shade cloth in late spring thru late summer. Also a Southern exposure or a location where the plants will receive plenty of bright, filtered light will work. I prefer to keep summer temperatures at about 75-85 degree days and 60-75 degree night, for winter 65-80 degree days and 55-60 degree nights. Cattleyas are quite adaptable and short periods of higher or lower temperature usual don’t damage the plants. In nature most Cattleyas are epiphytes growing high in trees where there is abundant air movement, your growing area needs to have good air movement.
Potting mix and Pots: I prefer New Zealand Pine bark, with “Kiwi Orchid Bark” being the best; it is hard and lasts 3-5 years. Douglas fir bark is also satisfactory. I mix 3 parts bark with 1 part perlite. I strive for consistence in the potting media and adjust the particle size based on pot size. For 2-3” pots I use fine grade bark and #2 perlite, for 4” pots medium bark and #3 perlite and for 5” plus pots large bark and #4 perlite. Plastic pots work well they are inexpensive, light weight and readily available, however clay pots may work better in hot humid climates, also baskets and cork slabs are suitable. Select a pot size that will allow for a maximum of 2-3 years of growth. Cattleyas don't like to be over-potted as oversized pots take too long to dry out causing root problems, remember an important key to good Cattleya culture is the drying down of root zone in between watering.
Re-potting and Dividing: Cattleyas generally start their growth cycle in the spring and summer. New growths may indicate new roots but I always wait until I see new root tips before re-potting as some plants will grow their roots after the growths mature. Please don’t underestimate the importance of re-potting when new roots arestarting to show, the stress on a newly potted plant is greatly reduced as the new roots will quickly reestablish it. Divisions should be made by cutting with a sterile tool or by pulling the bulbs apart. I try to keep the size of divisions between 3 and 5 bulbs. I remove most of the old media from the root system, often the newest roots are tightly intertwined with the media and removing it is damaging to them. As a result I may leave 5-10% of the old media in place in an effort to not damage these newer tightly intertwined roots they are the most effective roots and minimizing damage will lead to a quicker re-establishment.
Please feel free to contact me on any question regarding the growing of this genus. Once the basics are understood they are very rewarding. email@example.com