CATTLEYAS and LAELIAS
These orchids are the most sumptuous and exotic of all and are chosen for corsages.In nature there are about 50 species each of Cattleya and of Laelia from Central America, growing through the Amazon region to the south of Brazil. Their distinctive flowers and the tendency of these plants to grow in large colonies has meant that they have been vigorously over-collected and the status of many is endangered.The plants produce strong 'pseudobulbs' topped with one or more leathery leaves. Each year a dormant bud at the base grows into a new shoot. This thickens to produce the current year's pseudobulb. The flowers arise from the tip of the current year's growth and come in a range of colors from white and pink to green and purple. Some flower twice yearly.

Hybrids
Multitudes of hybrids have been bred over the years, many of which are easy to grow and easy to flower. Over 40 other genera have been bred into Cattleyas and Laelias, and notably among them Sophronitis has been used to introduce scarlet and Brassovola for the frilly lip.

Temperature and Humidity
Minimum night temperatures of 10 -15 C, depending on the plants' origin, are needed, but growth in summer is rapid at temperatures up to 26 C. A humid atmosphere, propelled by a fan is beneficial.

Light
In greenhouses, the normal maximum is 50% of full daylight or 2000-3000 foot candles. In hot weather shade sufficiently to ensure that the leaves are cool to the touch. If you are growing in the home give a bright situation but not direct sunlight, behind a net curtain, from April to September. These also make good conservatory plants as long as summer shade and good air movement can be provided.

Watering and Fertilizing
From March to September the compost should never be allowed to dry out completely. Water twice weekly and fertilize fortnightly with a recommended orchid fertilizer. From October to February, no fertilizer is needed, but water the plants when the compost appears dried out. It is better to underwater as the plants can stand neglect more than over watering!

Compost and potting
A medium bark mix will do well with added polystyrene spheres or perlite to keep it open. Chopped sphagnum helps retain humidity and some charcoal keeps it 'sweet'. New compost will keep the plant growing for two to three years before it turns acid and the plant needs repotting. Don't repot until the plants are crawling over the sides of the current pot and the best time to repot is when the new roots are just beginning to appear at the new shoot's base. If the plant has over eight pseudobulbs, the thick rhizome can be cut to give two equal sized plants which can be potted separately.

DENDROBIUM
There are over a thousand known species of Dendrobium (pronounced den-dro-bee-urn), and still more are being discovered in the highlands of New Guinea. This makes them the second largest orchid genus in the world after Bulbophyllum. The shape and form of their stems and leaves vary tremendously, but the pattern of flowers is fairly constant ranging in size from very small to very large. Typically the bases of the sepals are fused to the foot of the column and the lip base forming a mentum or 'chin' which often houses nectar.Dendrobiums come from South East Asia in an area that stretches from Northern India to the islands off the East coast of New Guinea and Australia to Polynesia. The latitude where they grow is important.The Equator runs through the middle of this territory and here it is always hot at sea level without any seasonal variation. However, the plants from north of the Tropic of Cancer and south of the Tropic of Capricorn are used to a much greater range of climate, with colder drier winters and warm wet summers. It is important, therefore, to know where every plant comes from.

For convenience, we consider cultural advice under three headings.
1. Nobile (pronounced no-bill-ay) type or Himalayan plants.
2. New Guinea plants3 Australian plants.

Nobile Dendrobiums
Are some of the easiest to grow but can be a little difficult to bloom regularly. Their flowers are showy with colors ranging from white through pink to purple, and the lip is often beautifully marked incontrasting colors. They make magnificent specimen plants. Others are yellow and brown, while the recently introduced Yamamoto hybrids have all the colors of the rainbow. The Himalayan climate is not unlike a warmer Switzerland, with bright, cold but dry winters.

Culture.
November-February: daytime temperatures can drop to 40° - 45° when you should not water or feed but give plenty of light and air movement. March-May or June: warmer and moister conditions. Buds develop and new growths appear. Water sparingly until the new shoots have grown good roots. From June-November corresponds to the monsoon period, warm and very wet. Give a low strength, high nitrogen feed in April and May, then feed weekly during maximum growth. Change to high potash for the last month. Note: If you do not dry and cool the plants during winter, you won't get flowers! Himalayan Dendrobiums from lower altitudes need a less harsh winter but still dry.New Guinea Dendrobiums.The climate varies with altitude and in mountainous areas there are cool, wet misty nights and morningsfollowed by warmer bright days. The exquisite cool and intermediate miniatures like D. cuthbertsonii grow here. Never allow them to dry out completely and feed often with dilute fertilizer. The river valleys between the mountain ranges are warmer and wetter, and home to some of the most exotic of the New Guinea orchids, e.g. D. lasianthera from the Sepik River basin, and many Latouria types with long-lasting flowers. All these need generous feeding and watering. The southern plains resemble Queensland but are wetter and very warm all year through. There is seasonal rainfall variation with a wetter summer and drier winter. Two of the outstanding species from this area (which are also found in Australia) are D. bigibbum (D. phalaenopsis) and D. canaliculatum, the former often found growing on rocks, thelatter on the trunks of paperbark trees. The easiest New Guinea plants for beginners are Dendrobiumoberrans (cool conditions); D. lawesii or D. antennatum (intermediate); and D. atroviolaceorn or D.bigibbum (warm).

Australian Dendrobiums
Dendrobium Kingianum or near relatives are the easiest to grow. The pseudobulbs or canes can beany length from 5cm. to 30cm. tall and are thin, and often spindly and tough. The leaves are narrowly oval with 2 to 4 at the top of each cane. The flowers appear in late winter and early spring in loose sprays at the tops of the canes on both the old and new canes. New plantlets or keikis may sometimes appear instead. These can be removed and potted separately after they have developed good roots or left on the parent plant where they will eventually flower also. There are 21010 flowers on a spray,each measuring 1- 3 cm. across, in shades of pink or purple. Other plants in this group may be tallerand have yellow, cream or white flowers. For their culture give intermediate temperatures and drier conditions than other Dendrobiums. Spray once a week and water generously in the spring and autumn with dilute feed. A few cold weeks in winter (down to 45°F), will encourage flowering.

Potting
Dendrobiums like to be in small pots with their roots confined. Bark, perlag and charcoal make up anopen mix which drains easily. Repot when either the compost becomes acid and soggy or when thepot is full of roots. This often means every year. Plants from the mountains of New Guinea like a little moss mixed with the bark or they can be grown on slabs of bark or tree fern on a mossy bed. Suchslabs need daily misting for most of the year. There are innumerable Dendrobium hybrids and these are almost always derived from species within one group, either Himalayan, Australian or from New Guinea. Surprisingly, most of the 'Singapore' orchids, although developed there, are derived from species of New Guinea and the adjacent islands and need much the same culture as the River Valley New Guinea species. So, when you buy a Dendrobium, ask which group it belongs to and where it comes from - and we don't mean which nursery!

ONCIDIUMS
These orchids can be varied in their cultural requirements, the hybrids are tolerant of wide ranges in temperature, and broadly speaking do best in an intermediate environment. There are many varieties however spread throughout the world, and cultural requirements differ widely amongst the species, hence the following is given as a general rule for most hybrids.\

Temperature and Humidity
Minimum night temperatures of 10 -15 C, depending on the plants' origin, are needed, but growth in summer is rapid at temperatures up to 26 C. A humid atmosphere, propelled by a fan is beneficial.

Light
In greenhouses, the normal maximum is 40/50% of full daylight or 1000-2500 foot candles. In hot weather shade sufficiently to ensure that the leaves are cool to the touch. If you are growing in the home give a bright situation but not direct sunlight, behind a net curtain, from April to September. These also make good conservatory plants as long as summer shade and good air movement can be provided.

Watering and Fertilizing
From March to September the compost should never be allowed to dry out completely. Water twice weekly and fertilise fortnightly with a recommended orchid fertiliser. From October to February, no fertiliser is needed, but water the plants when the compost appears dried out. It is better to underwater as the plants can stand neglect more than over watering!

Compost and potting
A medium bark mix will do well with added polystyrene spheres or perlite to keep it open. Chopped sphagnum helps retain humidity and some charcoal keeps it 'sweet'. New compost will keep the plant growing for two to three years before it turns acid and the plant needs repotting. The best time to repot is when the new roots are just beginning to appear at the new shoot's base.

VANDA'S
Light.
Vanda's need a lot of light, but they will be damaged when the sun reaches them through glass, so some shading is necessary, the correct level of shading has been reached when on a sunny day, your hand will cast a shadow on the plant but without a definite edge. Grow them high up, but don't forget to give them good air circulation.

Temperature.
With the exception of the cooler growing species such as coerulea, they like it hot, minimum night temps may fall to 55 F. as long as the plant is thoroughly dry by nightfall and daytime temperatures in the 80's the plant will be fine.

Water and feeding.
Water in the morinig, spraying the plants generously, leaving them for around 10 minutes or so to allow that watering to soak the roots, and then again. If the day is warm, water again around mid-day, this time with a feed mix, always bearing in mind that any water which has not evaporated from the leaves and their axils by sunset may cause a rot problem if the temperature drops too low. Tip, if you only have one or two Vandas,and live in cooler climates, water them by letting the roots soak in a bucket for 10 minutes or so each morning, and spray the leaves clean once in a while, on a warm day.