Phalaenopsis Orchids

Phalaenopsis is considered one of the easiest Orchids to grow. There are native to the tropics of Asia, Africa, and Australia. The name Phalaenopsis derives from the Greek word phalaina meaning ‘moth’ and ‘opsis’ that means like. Since the flat flowers appear along a graceful, arching stem, they look just like hovering moths or delicate butterflies, hence the nickname “moth” Orchids. These blooms can be 5-10 cm (2-4”) across and they have 2 round petals, 3 sepals, and a small, three-lobed lip at the bottom. Phalaenopsis Orchids are available in white, pink, yellow, violet, or red, or marked in combinations of 2 colours, with many variations to choose from. Flowering occurs in winter and spring though growers today are making them available year round. Individual blooms last for 2 months or more and well-established plants can flower 2 or 3 times a year. After the Orchid has finished blooming for the first time, cut the stem back to the second or third lowest bud. A new flower spike often emerges from this node in a few months. You can also prune the whole stem back to 5 cm (2”). This will sometimes promote a secondary spike.

Phalaenopsis Orchids

Light

  • Phalaenopsis need bright, indirect light. Early morning and late afternoon sun is fine but avoid mid-day sunlight especially in summer.
  • Phalaenopsis Orchids also grow well under fluorescent light when they are positioned 20-30 cm (8-12”) below the tubes.
  • Foliage should be semi-erect, leathery, and a medium olive-green colour. Dark green, limp leaves indicate not enough light.
     

Temperature & Humidity

  • Daytime temperatures of 21-29°C (70-85°F) are ideal. If temperatures are hotter than this increase water, humidity, and air movement around the plant.
  • Cooler night temperatures around 15-18°C (60-65°F) are perfect. In fall, an even lower night temperature of 13°C (55°F) for 4-6 weeks initiates the production of a flower spike.
     
  • Moth Orchids need a fairly high humidity, about 50- 70%. Misting is the most immediate solution but do this in the morning so the leaves are dry by nightfall.
  • You can also group plants together on trays of gravel and partially filled with water.
     

Watering

  • Phalaenopsis do not have pseudobulbs that store water so they can not be allowed to dry out completely between watering.
  • If your Orchid is potted in bark, water approximately every 5-7 days. Test the bark first for dryness about 2 cm (1”) below the surface.
  • If planted in sphagnum moss it may need water every 10 days or whenever it’s dried out 5 cm (2”) below the surface.
  • Remember that plastic pots hold moisture longer than clay. It’s a good idea to water in the morning on a sunny day. The water that collects in the centre of the plant will then have the chance to evaporate completely before dark. This avoids crown rot that would eventually kill the Orchid.
  • In particularly hot, dry summers, Phalaenopsis Orchids may need watering every 3 or 4 days. In the winter they may require water only every 10 days. Always feel the potting medium first and don’t overwater.
     

Fertilizing

  • Phalaenopsis need to be fed regularly. Schultz™ Water Soluble Plant Food for Orchids 19-31-17 provides strong growth. The 31% phosphorus encourages blooming. Dilute in water and follow the instructions on the label.

Re-Potting

  • The growing medium breaks down with constant watering so Phalaenopsis Orchids should be repotted every 1-2 years.
  • The best time to do re-potting is in late spring or fall when blooming is complete.
  • Use a well-drained Orchid mix.
  • Phalaenopsis produce new leaves at the top, rather than producing new growth from the base, so they rarely outgrow the size of the pot they are presently in.
     

Troubleshooting

  • Moth Orchids are relatively pest-free.
  • Spider mite, scale, mealybugs, and aphids can sometimes infest plants. Spray several times with Safer’s Insecticidal Soap.
  • Sudden temperature changes and cold drafts can cause flower buds to drop.
  • Mature plants that fail to bloom can often be encouraged to do so if given 2 months with 10°C (50°F) nights in the fall.