ORCHID CACTI (EPIPHYLLUMS)

These plants have been much neglected of late, despite their having the largest and most spectacular flowers in the cactus world (perhaps even the best flowers of any flowering plants). This neglect is probably due to the amount of space required for some of the plants in the past. This no longer holds true as many new varieties have been bred in recent years which are much smaller growing, and many basket varieties with a superb flower colour range are now available.

LIGHT

Full light from August - May. In summer slight shading is preferred - not too heavy or flowering may be reduced. A south-east window sill should be suitable for summer. A bronze tinge to the stems is normal but if most of the stem is coloured rather than green then the plants may be receiving too much sunshine.
To be safe, keep above 40 deg. F.(4 deg. C.) in winter. Nearer 50 deg. F. (10 deg. C.) is better in the spring (March) when the buds are growing.
Most orchid cacti are however very tolerant and can stand much lower (some down to just above freezing) and much higher temperatures than these.

COMPOST

This can be varied according to the ingredients available. The most important points are -
a)Neutral to slightly acid soil
b)Compost wets easily and drains easily and stays moderately moist for some time after watering.
A suggested compost to meet these requirements is (by volume):
1. Well - rotted leaf mould (oak is best) 60%
OR A mix of half moss-peat and half Sedge-peat 60%
2. A good loam 20%.
3. Sharp sand or Perlite or cat-litter 20%

WATERING

The most important thing is that the compost should never dry out completely.
Keep plants just barely moist in winter.
Water well during the spring & autumn main growing periods, allowing the top 1/3 rd of the compost to dry before watering again.
Give the plants a little less water after flowering, when they appreciate a little rest.
During the hot, dry summer months, gentle misting is beneficial. Rainwater is best, cold tea second and tap water only as a last resort.

FEEDING

With this compost some feeding will be beneficial when watering. I recommend any feed suitable for tomatoes (i.e. low nitrogen, high potash).
I feed every third watering during the spring and summer.

FLOWER PRODUCTION

Flowers should form on 2 -3 year old-plants. I recommend restricting the size of pot for maximum flower production. Orchid cacti with one or two cuttings per 6 inch or 8 inch pot can be kept at this size, and root bound, indefinitely. With mature plants, some of the old, marked stems should be cut back within six inches of the pot to encourage fresh growth and thus healthier and better-looking plants.

Other Epiphytic Cacti

The same cultural conditions as given above apply to the following plants. The only difference is that a little more light should be given than recommended for Epiphyllums.
Other epiphytes worth growing include Heliocereus, Selenicereus (Queen of the Night), Aporocactus (Rat's Tails), Nopalxochia, Disocactus and Rhipsalis.

EASTER CACTI The Easter Cacti are now known as Rhipsalidopsis or Hatiora. These produce their flowers in April and May, lasting for about six weeks, and will sometimes flower again in the autumn also. Cultivation is as for the Epiphyllum above, except that they should be kept cooler during the resting period from October until the buds become visible in the spring. Watering and feeding are then gradually increased and continued until late autumn. Easter cacti are more prone to segment drop on drying out than other epiphytes when watering is not regular.