Cymbidium orchid

About Cymbidium orchid

Cymbidiums are big, grassy-leaved orchids from Asia and Australia that carry tall spikes of 6-12 waxy, often fragrant flowers lasting one to three months, the classic corsage orchid (NC State). The large standard types need summer days of 75-85 F with nights of 50-60 F and a big day-to-night swing to set flower spikes, which is why they do best summered outdoors; miniature types take more heat. They need more light than moth orchids and plenty of water while growing.

Hardy outdoors only in zones 10-12 (NC State); it is grown indoors everywhere and is best summered outdoors in bright light once nights stay above about 50 F, where cool late-summer nights help it set buds (NC State, MU Extension).

When to plant

Timing is counted from your average last spring frost (and first fall frost). Sow & Tell works out the actual dates for your ZIP code.

Usually bought as a blooming nursery plant or divided from an older clump (NC State, UF/IFAS).

Growing it indoors

• Light: Bright light with a few hours of gentle direct sun, especially while it is growing, is what makes it bloom; harsh direct sun scorches the leaves (NC State; MU Extension says filtered to bright).
• Water: Water heavily with lukewarm water while it is growing so the mix stays moist but drains freely, and water less from fall (NC State, MU Extension). Never let it stand in water; soggy mix rots the roots.
• Humidity: NC State aims for 40-60 percent humidity; a pebble tray helps indoors in winter (Wisconsin Horticulture).
• Temperature: Standard types want 50-60 F nights and a big day-night swing to bloom; miniatures take 5-10 degrees more heat (NC State), and MU Extension gives 55 F nights, so a cool room suits it far better than a warm one.
• Feeding: Feed every 1-2 weeks during the growing season with a high-nitrogen orchid fertilizer (NC State); UF/IFAS warns too much fertilizer can stop it blooming and says to wait several weeks after repotting.
• Repotting: Repot when the mix breaks down or the plant outgrows its pot, about every two years, removing dead roots and dividing big clumps (UF/IFAS, Wisconsin Horticulture).

Soil

A commercial orchid mix labeled for cymbidiums, acid and well drained (NC State).

Pot in a commercial orchid mix labeled for cymbidiums, acid and free-draining (NC State).

Feeding

• Spring and summer, during the growing season: high-nitrogen orchid fertilizer. Every 1-2 weeks (NC State); wait several weeks after repotting before feeding (UF/IFAS).
• Fall and winter, while spikes form and bloom: less or none. Water less from fall (NC State); UF/IFAS warns too much fertilizer can stop orchids blooming.

Overfeeding and soggy mix are common mistakes; too much fertilizer can stop blooming and wet roots rot (UF/IFAS, NC State).

Harvest

Standard types bloom in winter and early spring, after a summer and fall of 50-60 F nights and a day-to-night swing of up to 25 degrees; miniature types bloom in summer (NC State). The spikes last 1-3 months and make good cut flowers; cut the spent spike at its base (Wisconsin Horticulture).

Varieties (10)

NC State Extension names 9 species and 1 hybrid cultivar; most cymbidiums sold are unnamed hybrids.

Pests to watch for

Aphids, Twospotted spider mite, Scale insects, Mealybugs, Thrips

Diseases and problems

Root and crown rot, Mosaic viruses, Fungal leaf spots, Orchid viruses

In the kitchen

Safety: Not listed as poisonous in the sources we opened (NC State gives no toxicity, and the ASPCA has no cymbidium entry).

Pets: Not listed by the ASPCA (no Cymbidium entry on its plant lists).