Growing epiphytic orchids in New Zealand by Jim Gilchrist
Most of us have seen crucifix orchids Epidendrum ibaguense growing in gardens around the warmer parts of New Zealand usually as terrestrials occasionally as epiphytes. These belong to the family Epidendiae which also includes encylias, cattleyas, laelias, sophronitis, brassavola, leptotoes and many others. The purpose of this article is to talk about cattleyas and laelias and hopefully dispel a few myths.
The first myth is that cattleyas need to be grown warm. That is true of some of the unifoliate species. However, most of the biofoliate cattleyas and laelias come from high latitude areas of South America where they grow cool.
The second myth is that they will not tolerate frosts. This is true if the plant is wet in particular the roots. However, in many areas where they are found in South America, frosts occur on the open ground in the near vicinity of where the plants are to be found. The plants are not silly they find places where they are out of the frost zone up trees or on cliff faces. I have often wondered if the trees they grow on are actually warmer than the ambient temperature around them. On rocks or cliff faces the stone absorbs heat from the sun during the day then slowly re-radiates the heat during the night keeping the plants warm. Recently on TV there was an English gardening program called "Beautiful Gardens". On one of these programs it featured a garden in the South of England where the original creators of the garden had built large stone walls and then planted Bananas, Cordylines, tree ferns and palms on the south facing side.
I was originally inspired to try my hand at growing epiphytically by a series of Books by a gentleman by the name J N Rentoul. Unfortunately the books are now out of print. However, the books can often be picked up second hand at orchids society trading tables at their shows. At about the time I purchased the first of these books I purchased a tray of cattleya hybrid seedlings from Andy Easton at the MT Albert Orchid Show Spring 1988. Some of these I grew on ponga slabs and some in pots which I grew in my fernery at my address in Birkdale Auckland. Now these plants grew like weeds that summer and into autumn. However, I lost most of the plants that were in pots during the winter while the plants on the ponga survived. On refection I think I was lucky. My section was on the side of a steep street and faced west. My neighbour above me who had large trees on his property also shaded it. Sarcochilus, prominaes and odontoglossoms grew really well. However, I did have a large red She Oak growing at the back of my place and on this I planted a number of orchids and they thrived. As a result I planted two more She Oaks but the green variety they grew real well and I had orchids growing on them to. When I sold that property and moved to our new address the new owners cut down the trees and used them for firewood. I hate to think what happened to the orchids.
Cattleya group orchids need to be grown as succulents. They need to dry out quickly after watering. In their natural environment they usually enjoy dry winters and wet summers. Unfortunately the opposite to NZ conditions but I have found that they still survive our conditions because when it rains it generally does not get too cold and in the summer we can occasionally give them a squirt when we water the garden.
Where I live at Pottering About Garden Centre in Otakiri on the Eastern BOP Plains I have the following orchids growing outside and have survived more than one winter. Cattleyas - Forbesii, Intermedia, aurantiaca, loddigesi and harrisoniana. Laelia anceps, pumila, epidendrum nocturnum, bifranaria, Harrisoniana. Dendrobium kingianum, speciosum and their hybrids. These plants are growing on feijoes and juvenile macrocarpa. I have planted green She Oaks, Puriri, and Brazilian Pepper with the sole purpose of planting orchids and bromeliads. I the past I have grown orchids on ponga mounts, wooden slate baskets, wire baskets and plastic pots. The plants in the plastic pots have never grown as well as the plants in the plastic baskets or on the mounts. I believe there are a number of reasons for this. The first is that it takes a long time for the plants to grow out and it is very easy to damage the root ball. Second there is nowhere enough air movement over the roots and third there is usually either too much or not enough fertilizer. Growing on a tree the plants are fertilized by dust and pollen washing down over the roots each time it rains.
I have recently been able to purchase from an importer the traditional Asian orchid Pot and am repotting all of my orchids into these pots. Anybody who has visited the orchid gardens in Singapore will have seen these pots in use. I have found that usually within a week or two of repotting cattleya type orchids into these pots an improvement in plant health can be detected the existing roots fatten up and become white with a new coat of vellimum. New roots start to appear from the rhizomes with long green growing tips and new growth starting to appear and within a further short space of time the new growth are larger and fatter than any previous growth.
Another advantage of growing epiphytically is that there is no weed problem. If a fern becomes established in a plastic pot growing an orchid the fern will kill it. On a mount the fern won't usually survive however in a clay orchid pot or wooden basket they both seem to enhance each other.
