Growing Cymbidiums in the Sacramento/San Joaquin Valley
Cymbidiums are easy to grow. They tolerate the valley climate well, and minimal effort is rewarded with spectacular spikes of long lasting flowers. And, of course, they’re orchids - highly specialized, fascinating flowers with endless variety. For people who have never grown orchids, a cymbidium is a good first choice.
Cymbidiums are available in both standard and miniature varieties, and have flowers in shades of white, yellow, pink, maroon, bronze, green and combinations of these colors. The plants have short, thickened stems, called pseudobulbs, and long grass-like leaves. As new pseudobulbs grow, they form clumps. The old, leafless pseudobulbs help store water and food, and flowers are produced in the spring by pseudobulbs that grew and matured during the previous summer.
Cymbidiums are outdoor orchids - they require night temperatures 60° and below all year. They prefer cool, sunny days, but they will tolerate high summer temperatures if they’re protected from drying winds and hot sun. In winter, protect them from frost by placing them under a patio roof or evergreen tree. See member growing areas.
Cymbidiums need all the light you can give them, short of burning the leaves. Place them in sun or partial sun when days are 80°-85°F or below. During hot weather , keep them out of direct sun (direct sun will sunburn the leaves) but make sure they receive at least 4 hours of sunlight each day. INSUFFICIENT LIGHT IS THE MOST COMMON REASON CYMBIDIUMS FAIL TO FLOWER.
Like all orchids, cymbidiums prefer 50% humidity or more, but they will tolerate less if not under watered or exposed to dry winds. During periods of active growth, plant s should be watered copiously, often more than once a week. Don’t use softened water! As days grow cooler and shorter, reduce watering. Fertilize with a balanced fertilizer. Easiest is the slow-release type. Recommended is Nutricote, available from U.S. Orchid Supplies (www.usorchidsupplies.com) or in 2 pound containers from Home Depot under the Dynamite brand. Otherwise, use a balanced all-purpose fertilizer once a month.
Plants should be repotted into fresh mix every two to three years, depending on the health of the mix. If it is broken down and soft, repot. Potting is best done right after flowering, to allow maximum time to reestablish before spiking in late summer. Do not be too anxious to divide, as best flowering is on large plants. Never divide below two or three bulbs, as flowering will suffer. Use a well-drained, water-retentive mix (such as medium fir bark or coconut husk chips) and do not use too large a pot. The plant will stay too wet.
Insecticidal soaps will take care of most buggy pests, and fungicides will help control root rot and leaf diseases (ask your garden center for the appropriate one). Avoid using pesticides that use petroleum distillates because they can injure the flowers. Slugs and snails will eat new growth and flower buds, so protect against them.