Orchids in the home

By Howard Drury

Introduction

Many people think that orchids are expensive to purchase, and difficult to grow, the aim of this fact sheet is to dispel some of these myths and legends. Orchids are magnificent, beautiful, and fascinating, yet remarkably easy to grow if a few simple rules are followed. Coupled with the many legends surrounding these plants, come the theories that expensive osmunda fibre is required, together with high temperatures. Fortunately, with today’s modern hybrids that are available, cultivation is much easier and the plants will thrive in a range of conditions. Given suitable conditions and proper care, orchids can go on to bloom happily for many years.

Family Size

The family Orchidaceae includes over 750 genera (like your surname), with more than 20,000 species (individual family members). There are many thousands of man-made hybrids. Approximately half the species are terrestrial (growing on the ground), and half are epiphytic (clinging to trees, shrubs or rocky surfaces). Most of the orchids grown in the home are epiphytes, only one terrestrial member, Paphiopedilum is commonly grown. The orchid family is the third-largest group of all plants, with more than fifty species being found in the British Isles alone, with more being found in previously relatively unexplored areas of the world.

History and Origins

Scientists believe now that orchids probably originated as early as 100 to 120 million years ago, possibly in Malaysia. The Greek philosopher Theophrastus (372 to 287 B.C.) made reference to a group of plants called Orchis a term which in Greek means "testicle" thought to describe the roots of the orchid. It is thought that orchids were unknown in Europe until the mid seventeenth century. Today, the Royal Horticultural Society receives as many as 175 applications per month to register new cultivars.

Growth and Habit

Orchids are found growing wild in most parts of the world, from sea level to mountainous regions thousands of feet high. Orchids vary in height from an inch or so to giants several times taller than man. Most terrestrial orchids have thick fleshy roots with fine fibrous roots attached to them, as do many terrestrial plants. These roots take up the plant's nutrient needs. The epiphytic species normally have aerial roots in addition to a root system at the base of the plant. In the wild, these aerial roots enable the plants to twine, creep or climb their way over suitable hosts; such roots are often thick and cylindrical. They will cling to any suitable moist surface, such as damp bark. Epiphytic orchids tend to grow in one of two ways, for example, some plants such as the Vanda family produce a main single stem arising from a tuft of roots at the base. This stem, which normally grows upright, has leaves along its length and will reach several feet in height. Side shoots are produced occasionally, but these are usually less vigorous and much smaller than the main stem. Flowers appear between the leaf axils near the top growths, whilst aerial roots are produced from the lower leaf axils. The roots of these plants may cling to any available surface; technically, these plants are known as monopodial, which means single footed.

The second pattern of growth is known as sympodial and is typical of Epiphytic orchids, which typically have many stems, all of which appear from a central or horizontal rhizome, which in pots sits on the surface of the potting compost putting down feeder roots into the mixture. Thick stems which are called pseudobulbs come from the rhizome periodically; these pseudobulbs act as storage organs for food and water and can carry plants through drought. These green pseudobulbs vary widely in shape and size and in some cases, look like ordinary stems, they vary from under an inch to several feet in size, although those grown as indoor plants rarely exceed 8". Each pseudobulb has one or more leaves at its tip from where, eventually, a flower stem will appear or, occasionally, from the base after which the pseudobulb slowly dies. A new pseudobulb is produced annually at the end of a new length of rhizome and as it grows the old flowered pseudobulbs gradually wither and dry up, this process of dying may take up to 5 years. Old flowered bulbs are sometimes called back bulbs. The foliage of orchids is very variable according to the species, and no generalization can really be made.

Orchid Flowers

In terms of flower pattern virtually all orchids are alike in so much as they have three outer floral segments (sepals) and three inner segments (petals) one of which is modified into the lip (labellum). The stamens and the stigma form what is known as the column. This floral structure is common to all orchids, from the massive blooms down to those requiring a magnifying glass to be seen. Some orchids are very colourful, others dull and insignificant. Some have a delightful perfume, whilst others give off less than pleasant odours. Flowers may be produced singly or in clusters, flower stalks may be erect or drooping, and most blooms will last 3 to 6 weeks.(Some species will last up to 12 weeks). Unlike most flowers, if orchids are to be used as cut bloom, they should be removed early as they will last as long-standing in water as they do on the plant.

Orchids as Pot Plants

Orchids have become popular as pot plants because they are good value for money, having a long flowering period, are relatively easy to keep from year to year, and are now produced relatively cheaply by a method known as tissue culture. With the wide range of orchids available, it is possible to select plants suited to various rooms in the house or the greenhouse.

Temperature

Orchids conveniently fit into one of three boxes in so far as temperature requirements are concerned. The cool house varieties need a minimum winter night temperature of 50 F, in summer the night temperature should not rise above 65 F. The intermediate varieties require a minimum overnight temperature of 55 F and a summer night temperature of around 60 F. The warm house varieties should have a winter night temperature of not less than 60 F, in summer the night temperature should not fall below 65 F. In all instances the daytime temperature should be at least 10 F higher than the night temperatures. However, most orchids will suffer if the daytime temperature rises above 90 F, although they will tolerate higher temperatures for short periods if the humidity is high. Orchids prefer an even temperature and fluctuations should be avoided. High humidity is essential for all types, except during the short rest period (if occurs) and plants may be stood on damp pebbles or moist peat, the foliage may be misted once or twice a day when temperatures are in excess of 70 F.

Watering

Many orchids are killed by over watering, even actively growing orchids should only be moderately watered on each occasion, it is often advisable with modern potting mixtures to allow the surface around the plant to dry out almost completely between watering. With a free draining mixture, watering are unlikely to be necessary more than once a week. Orchids growing on sections of osmunda fibre, or similar bark type supports, may need more frequent soakings, but plants should never be watered before the support begins to feel dry. Plants growing in hanging baskets may be treated as above, where wooden baskets or supports are used, these may be separately soaked in a bucket of water for a few minutes. A number of orchid groups have short rest periods, when growth is reduced and the leaves of some species drop off, this usually occurs in winter and during this period only water orchids sufficiently to stop the potting mixture from drying out completely. Rainwater is preferable to tap water.

Feeding

Although orchids will grow and flower quite well under the right conditions, it has recently been proved that the orchid like many other plants requires some form of nourishment. This is best applied as a foliar feed, during the summer months on an N P K basis of 20 10 10, this means the plant is being offered 20 units of Nitrogen, 10 of Phosphates, and 10 of Potash. In the early autumn this can be adjusted to a 20 20 20, and fertilizers should be used at half the prescribed rate. Some authorities apply fertilizers at 3 out of 4 waterings using the latter to flush out any build up of salts, others feed once and flush out three times.

Humidity

Orchids need a humid environment in order to thrive. Plants grown in the greenhouse can have the air moistened by damping down the paths, earth and staging between the pots, this should be done in the early morning nearly every day of the year except for cold wet days. As the weather becomes warmer, it will be necessary to give a further damping down during the day and possibly one in the evening. Tap water may be used quite successfully for damping down. Plants grown in the home should be stood on trays of aggregate (e.g. pebbles, Perlag or similar) and kept moist at all times. A group of orchid plants growing together will create their own microclimate.

Ventilation

Most orchids, particularly the cool types that the amateur is likely to begin with, welcome plenty of fresh air, but like most houseplants, resent icy blasts and draughts and may because of this may drop their flower buds, or even die. The normal opening of windows in the home will provide most orchids with sufficient fresh air. Plants grown in the greenhouse will require ventilators low down to prevent the escape of precious humidity. Roof ventilators will satisfactorily reduce high temperatures, but also quickly allow the valuable humidity level to drop drastically. Electric fans are very useful to keep the humid air moving without introducing draughts, thermostatically controlled ventilators and louvres are good investments.

Light

Orchids need good light, but some protection from bright sunlight. Plants in the home therefore are the happiest on east or west facing window sills in spring, summer and autumn, however, plants should be moved to a south facing window during the winter. Plants in the greenhouse should be shaded from the bright sun with either lath blinds or a greenhouse shading material. Remember that orchids growing in the wild would receive some direct sunlight or be found growing in dappled shade.

Potting Mixtures

In the wild, orchids would be found growing in a range of different mediums, all of which would be bark like and free draining. Traditional potting mixtures for epiphytic orchids used to include two parts osmunda fibre and one part sphagnum moss with a dusting of bonemeal. Osmunda fibre and tree bark can be purchased in the form of slabs or blocks on which orchids may be grown. Orchids have also been grown on rice husks, pumice, charcoal, sand and gravel. With the advent of Perlite the most common mixture in the U.K. is based upon two parts of coarse grade sphagnum moss to one part Perlite with the Ph adjusted to 6.0 with the addition of limestone and Dolomite of lime, a fertilizer which contains a balance of nutrients and trace elements should also be added. Some growers find the addition of Perlite difficult and have varied the mixture by either reducing the Perlite and adding bark, or simply adding bark to open up the compost. These two materials have revolutionised orchid potting mixtures and brought them into the range of everyone's pocket as osmunda fibre can be very expensive

Propagation

The group of sympodial orchids can be propagated in early spring or directly after the plant has finished flowering. As a first step it is a good idea to cut through the rhizome a month or so before actually dividing the plant, this gives cut surfaces time to heal before removal and re potting. Do not make divisions of less than three bulbs, clean and trim the plant at the same time and always use a clean sterilized knife when severing rhizomes. Once the cuts have been made and surfaces healed, knock the plant out of its pot and gently pull the plant apart, sorting out carefully your new divisions. It is also possible to increase this type of orchid by removing the leafless back bulbs and potting them into small pots. The pots need to be placed in a warm shady situation, or alternatively, enclosed in a polythene bag. After a few weeks most will have made a new growth and can be removed from the polythene and grown normally.

Most monopodial orchids can only be propagated with difficulty, in some cases small plantlets are produced as off sets at the base of the plant or the node of the flower stem. Once these growths, known as keiki, have produced roots severe these small plantlets and pot up in the normal way. Water sparingly for the first 4 6 weeks. It is also possible to take tip cuttings which must include at least two aerial roots, pot in the same way, save the parent plant to encourage new growth somewhere along the remaining stem. Regular misting daily will encourage more rapid shoot production.

Potting and Repotting

Orchids should be periodically repotted at different intervals according to the species or hybrid. Prior to repotting always trim and tidy the plant first, in the case of sympodial orchids, remove any dead leaf bracts around the pseudobulbs. Carefully remove the plant from its pot and examine its root system and the existing compost, look out for any signs of root decay. If plant and roots are in excellent condition select a slightly larger pot that will permit a further year's growth and crock the bottom using coarse Perlag or cubes of polystyrene to ensure free drainage. Place the plant within the pot at the correct planting depth and pour in the compost around the root ball. Gently firm and tap the pot a few times to ensure it is evenly packed around the sides. Should the roots and the compost appear decayed, remove all the compost and trim away any decayed roots so that only healthy roots remain. If orchids are sympodial, remove any leafless pseudobulbs by cutting with a sterilized knife, the short rhizome that connect the bulbs. Plants with decayed roots should be divided into pieces that contain two pseudobulbs and a new growth. Repot and place drainage material in the bottom of the pot to ensure good drainage. It is unnecessary to repot most orchids more often than once every two years.

Where plants are grown on such supports as blocks of osmunda fibre, tree fern, or wood, roots are not surrounded by any potting mixture. When repotting, the base of any plant to be secured by this method should be soaked in water and allowed to drain for half an hour. Place a handful of sphagnum moss under the moist base of the orchid and spread its roots gently over the moss pad and tie them down using copper wire or nylon string.

Pests and Diseases

Orchids are not particularly susceptible to pests if strict rules of hygiene are adhered to at all times, beginning with purchasing clean healthy plants and growing them in hygienic conditions. Orchids are easily damaged by pesticides, avoid spraying plants which are exposed to bright sunlight or extremes of temperature. Seedlings and open blooms are most sensitive to pesticides. Mealy bugs and scale insects sometimes attach themselves to pseudobulbs, stems, and leaves. In cases of small infestations, paint individual attacks with methylated spirits, in other cases use a systemic insecticide. Red spider mites can do much damage to orchids and multiply rapidly, they are almost invisible and leave a silvery web appearance over the plant. Use insecticidal sprays as directed on the container. Slugs and snails can do considerable damage to root systems and young leaves, use proprietary slug killers to keep them under control.

Orchids suffer from few diseases and are likely to be trouble free if grown well; decay can set in as a result of unfavourable growing conditions. Where brown or black spots combined with a softening of tissue occurs, it is important to cut back with a clean knife to healthy tissue. If the rot has gone too far and cut surfaces are still showing black decay, and the plant is collapsing into a soggy mess, it is best discarded. Any cut surfaces should be dusted with Sulphur or a proprietary fungicide. A number of viruses can occur as a result of poor hygiene, in severe cases plants should be burnt as there is no other control.

The Plants

Cymbidiums

Cymbidiums are by far the most popular orchid, the easiest to cultivate, as in nature they grow in a variety of climates from tropical rain forests to desert. They produce flowers in a wide range of colours and have interesting lip markings. The name cymbidium derives from the Greek word 'kymbe' meaning boat, referring to the lip. Two types of cymbidium are available, standards and miniatures. The latter is more suited as a houseplant, as the large flowered types tend to be too large for today's modern homes. Cymbidiums are cool growing orchids, tolerating near freezing temperatures to 110 F, although they are happier given 60 F night temperature in the summer and night temperature of 50 F in the winter. Repot cymbidiums in the spring and place them out of doors in a sheltered position during the summer months, bringing them inside before the autumn. Only do this if you live in a sheltered area, in the South or Midlands.

Phalaenopsis

These exotic tropical orchids from the Far East are known as the Moth Orchids due to their striking resemblance to a moth. Discovered in 1852 by a Dutch Botanist, the name Phalaenopsis means 'moth appearance' in Greek. Many hybrids are available today in a wide range of colours, these have been bred so that successive flowers on spikes will open in order that the spray will be in bloom for several months. In the wild, these epiphytic monopodial orchids are found growing on trees and frequently have long aerial roots. Phalaenopsis orchids need high temperatures and high humidity. The ideal night temperature is around 65 F with a day temperature some 5 10 F higher. Some growers use a compost mix of two parts bark, two parts sphagnum moss, one part Perlite with a Ph of 6 and get good results. Excellent results can also be obtained with a bark compost using chips of approximately
1/2" in size, but extra care is needed with watering and the centre of the plant should be kept dry. Place plants in a light location.

Odontoglossums

This orchid is sometimes called the Princess of the high Andes, as most species come from Central and South America and grow at high altitudes. During the early 1800s when these were first discovered, bulbs exchanged hands for over £1,000, in today's terms this would equal £100,000 just for one plant. Within this group are some of the most beautiful flowers in the world and some of the best modern hybrids. Flowers are found in almost every colour, all sorts of spotted and patterned types are also available, flower spikes may carry up to 30 blooms. The name in Greek means 'tooth and tongue' and refers to the tooth like projections on the lip of plants in this family. The Odontoglossum family consists of members that will tolerate a wide range of temperatures, however, most are quite happy given a night temperature of 50 to 55 F. The day temperature should not rise above 80 F if possible. Healthy well grown plants will tolerate temperatures as low as 40 F and as high as 90 F. Watering is critical with this group of orchids, do not over water and use rainwater if possible when needed. It is best to keep plants a little on the dry side. Aphids sometimes, along with red spider mite, attack this plant and these should be eliminated using an appropriate insecticide. A good potting mixture for these orchids consists of two parts sphagnum moss peat, two parts Sequoia bark, one part Perlite with the Ph adjusted to 6 and a base fertilizer added to the peat. Repot annually when new growth is 1.5" long, ideally these orchids are best kept under greenhouse conditions when not in flower. If this is not possible, place plants in a light location indoors, but not in direct sun.

List of Specialist Orchid Nurseries

 Grange Nurseries, North View Road, Westgate Hill, Bradford, West Yorkshire
Tel : (01274) 682120 Yorkshire (West) BD4 6NS

Burnham Nurseries Ltd
& Orchid Paradise Forches Cross, Newton Abbot, Devon TQ12 6PZ
Tel : (01626) 352233

Creepers Nursery 1 Morie Street Wandsworth London
SW18 1SL

Equatorial Plant Company 7 Gray Lane, Barnard Castle, Co Durham DL12 8PD
Tel : (01833) 690519

Laneside Alpine & Hardy Orchid Nursery 74 Croston Road, Garstang, Preston PR3 1HR (Hardy Orchids)
Tel: 01995 605537

Laurence Hobbs Orchids Ltd Bailiffs Cottage Nurseries, Hophurst Lane, Crawley Down, West Sussex RH10 4LN
Tel : 01342 715142

McBean's Orchids Cooksbridge, Lewes, West Sussex BN8 4PR Tel : 01273 400228

Only Phalaenopsis 141 Kings Acre Rd, Hereford
Tel : 01432 268650 Hereford HR4 0SP

Orchids by Peter White 61 Stanwell Lea, Middleton Cheney, Banbury, Oxfordshire OX17 2RF

Phoenix Orchids Pennine House, 50 Pinnar Lane, Southowram, Halifax, West Yorkshire HX3 9QT
Tel : 01422 362509   (May be now closed)

Plested Orchids 38 Florence Road, College Town, Sandhurst, Berkshire GU47 0QD
Tel : 01276 32947

Royden Orchids Perks Lane, Prestwood, Bucks
Tel : 01494 863224 Buckinghamshire HP16 0JD

 This list is not exhaustive, and is constantly being changed. Many other nurseries also grow and supply orchids, remember to only purchase good quality plants from reliable sources.

Societies

There are some 30 plus Orchid Societies that are members of the British Orchid Council, and these Societies and their Secretaries' addresses can be obtained from the excellant website of  The Orchid Society

Books for further reading

 Illustrated Guide To Growing Your Own Orchids, Ritterhausen. '85 £14.95.

Macdonald Encyclopaedia of Orchids, A.Fanfani. '89 £9.95.

Orchids, A.Bristow '87 £3.95 Wisley Handbook.

Orchids, P.McKenzie Black. '83 £5.95

Orchids In Colour, Ritterhausen. '79 £6.95

(C) 2022. This material has been produced by Howard Drury and must not be reproduced in part or full without the written consent of Howard Drury, Kings Heath Birmingham, B13 0SJ.
JHD/13/02/2022