Cymbidiums boast some of the most dramatic flowers in the orchid kingdom. And you can enjoy their magnificent blooms if you follow a few simple guidelines for growing these plants. We call it Cymbidium Success!
Cymbidiums are easy growers (and bloomers) in temperate climates such as California, where they're grown outside year round. The warm, sunny days (80-90 degrees) and cool nights (40-50 degrees) are perfect for growing healthy plants that bloom.
In Northern climates , the best cymbidiums are usually grown in greenhouses. Don't have a greenhouse? Don't worry. Even if you're climate challenged, you can still have Cymbidium Success by growing them outdoors in the summer.
In nature, these plants grow in rocky soil that doesn't hold moisture and drains quickly. The LECA pebbles in our hydroponic system are and ideal for growing cymbidiums because they closely resemble the growing media these plants find in nature.
LECA pebbles are also great for outdoor growing because they never breakdown or decay, insuring a healthy root system in any weather. Traditional growing materials (bark, moss, etc.) break down and decay outdoors. This makes watering tricky and invites root rot on your plants. LECA pebbles are also ceramic, so they won't attract insects.
Growing cymbidiums the bloom is as easy as 1 - 2 - 3.
Note: If you can't move your plants outside during the summer months, growing cymbidium orchids probably isn't for you.
The key to Cymbidium Success is establishing an outdoor growing season in the summer and a blooming season indoors in the winter. Then, simply adjust your plant care to each season.
The growing season begins when you move your plants outdoors in the spring. Check your local weather for the last frost date in your area.
Water + Nutrients for Outdoor Growing: Cymbidiums don't like wet feet! In nature these plants grow in rocky soil that holds little moisture. The only nutrition they get is from bird droppings and other decaying material. So be stingy with water and nutrients. "When in doubt, do without" applies here.
Water to only 1/4 on gauge (or about 1/2" in saucer) - no more! This should be easy because anything more should drain away. You can even water with the garden hose! Water in the reservoir at the bottom of the pot should never be more than 1/2" deep. If it is, your saucer is too deep and the roots will stay wet too long. Not good - cut saucer a little lower.
Cymbidiums do not want to be standing in water all the time. Allow enough time between waterings for the plants to sit completely dry for several days between waterings.
I use and recommend Dyna-Gro "Grow Formula 7-9-5" (1/2 tsp per gallon) every watering. I also add Dyna-Gro "Mag-Pro 2-15-4" (1/2 tsp per gallon) to the mix about once a month to give the flowering process a boost.
Clear water from rain showers will flush the system and balance your nutrition program. If your plants are protected from the rain, water thoroughly with plain water every couple of weeks.
Temps: Cymbidiums require a wide range of temperatures (that's why they're not suited for indoor growing). They enjoy temperatures that reach into the 90's during the day. To initiate a bloom cycle however, temperatures must drop into the low to mid 40's at night. So keep your plants outside in the fall until the thermometer drops to the upper 30's(!). You might even see frost - don't worry - these plants can take it! Damage occurs if temps drop below 30 degrees however.
After a couple of weeks with night time temperatures droppong into the high 30's - low 40's, it's time to move indoors. A sunny window is best. Try to keep plants as cool as possible, especially at night, preferably around 55 degrees. Too warm and new flower buds might drop off.
In January things start to get exciting because you can start looking for flower spikes. After the first flowers begin to open, move your plant(s) away from the sun and display them wherever they look their best. Your plants have stored up all the energy they need to complete their flowering cycle. Cooler temperatures (away fom the sun) will prolong the life of the blooms.
Water + Nutrients for Indoor Growing: Moving your plants indoors slows their metabolism, so cut back on the water and stop nutrients altogether. This encourages the bloom cycle to begin. Water sparingly and slowly - when the gauge moves - stop! Don't rewater until bottom of pot is dry, usually about once a week or so. The seasons have changed and these plants don't need much water now.
When the first flower spikes appear (look for them at the base of the plant), start feeding again using a "bloom formula". I use Dyna-Gro "Bloom 3-12-6" (1/2 tsp per gallon) to encourage bigger, longer lasting flowers. Continue throughout the bloom cycle.
Note: "Bloom" nutrients won't make your plants bloom - only light and temperature can do that. Bloom nutrients simply encourage bigger, brighter blooms that last longer.
After the blooms have faded, cymbidiums go dormant, which corresponds to the dry season in their native habitat. Reduce watering even more. Pour water through the pebbles once a week to keep the plant from dehydrating - and that's all. No standing water at the base.
Don't expect new growth until plants go outside again in the spring and a new growing season begins.
For more on Cymbidiums and hydroponics: