Cattleya "violacea" orchid in bloom.
image by Dalton Holland Baptista:commons.wikimedia.org
Cattleya orchids are one genus in the vast family of perennial flowering plants known as orchidaceae. Cattleya orchids vary widely in the coloration, petal shape and throat detail of their blooms. They can produce one or more stunning blooms on each stem, and their stems are unique from other orchids. Cattleyas have what looks like a swollen surfboard-shaped reservoir in the stem called a pseudobulb that holds water and nutrients for the plant. As cattleyas are epiphytic this reservoir helps to meet their needs when the surrounding air environment cannot.
Provide lots of bright, indirect light and some daily sun for your cattleya when it is not in bloom. When it is in flower, provide only bright indirect light to preserve the bloom. As with many other species of plants, light controls blooming and if kept in too dim a setting your cattleya will refuse to bloom. To accommodate its need for direct sunlight without burning and drying out, situate the plant so that it receives direct morning sun and late afternoon sun but is protected from the direct sun during midday.
Plant your cattleya orchids in a coarsely textured commercial orchid mix containing shredded bark, charcoal and perlite. Being epiphytic, cattleyas like air around their roots and fast-draining coarse planting material provides this. Orchid mix for terrestrial orchids will be similar but of a finer texture and it will have some potting soil and peat moss mixed in it. Look for the chunkier version without soil.
House your cattleya so that the ambient temperatures stay between 55 and 60 degrees F overnight and between 70 and 85 degrees F during daylight hours. Cattleya can tolerate warmer daytime temperatures but only if there is very high ambient humidity and watering is increased to every few days. The uppermost range under those conditions is about 95 degrees F.
Water your cattleya by dousing the roots and growing medium weekly as well as by raising the ambient humidity around the plant. Run the entire pot under slow-flowing tepid water once a week or when the medium is dry and the pot feels light when lifted. Allow the excess water to drain off and then put the plant back in its saucer or decorative container. Raise the ambient humidity by misting the orchid daily over the roots, stem and bloom. Create a humidity tray for under the orchid by filling a shallow watertight tray or saucer with small stones and filling with water up to the lip. Set the orchid atop the tray and refill the water as it evaporates.
Fertilize your cattleya either once a month or once a week with an orchid food diluted with water. Always apply fertilizer over an orchid that has just been watered to prevent burn and speed the uptake of the applied minerals. For weekly feeding use just 1/4 of the recommended dose of fertilizer to a full measure of water. For monthly feeding use 3/4 to a full dose of fertilizer to a full measure of water. Pour the fertilizer solution slowly and evenly over the roots and planting medium but don't pour over the leaves as this can lead to spotting and invite disease.