Growing Orchids in the Hot Greenhouse

If you have a hot greenhouse, there is a completely different range of orchids that is easy to grow with sufficient heat.

Phalaenopsis

This reigns supreme among hothouse orchids. Commonly known as `moth’ orchids because of the spread of their pure white petals, they are monopodial in habit, but do not attain any great height. A standard-sized plant will carry up to six large, broad leaves, that are thick and fleshy, compensating the plant for its lack of pseudo-bulbs. They are often grown on pieces of wood and have a downward habit, at the same time producing the typical orchid aerial roots, flattened and silvery on the outside. Orchids that are grown on wood very soon adhere to it with these strong, clinging roots; within a few months supporting ties can be removed and the plant becomes self-supporting.

The foliage on some of the phalaenopsis species is beautifully marked and mottled with light and dark grey-green spots. The undersides of these leaves may be purple, making a most handsome-looking plant, even when it is not in flower. The colours of phalaenopsis are somewhat restricted to white and pink, but there are a few yellow ones that have been recently introduced, as well as some very fine reds and mauves.

Phalaenopsis are expensive plants to raise from seed, mainly owing to the high temperatures they require, but the grower is amply rewarded by long, drooping sprays of delicate and beautiful flowers. The flowers are large and circular and will last for many weeks; when it has finished flowering, a flower spike will often grow again from its length, producing even more flowers. A large, mature plant that has been well grown is almost continuously in bloom. Phalaenopsis hybrids have no set time for flowering and can be in bloom at any time of the year.

 

Vandas

The vandas are a further group of sun-loving, hot-growing orchids that are monopodial in habit, with some varieties growing to a height of 1.2-1.5m (4-5 ft). However, the average flowering size is about 25-30cm (9-12 in) tall. Long aerial roots sometimes accompany the growth of these most attractive plants. Their flowering season is variable, and they are capable of blooming twice in one year. The flower spikes come from the axils of the leaves and carry up to a dozen large, long-lasting blooms.

There are many colourful species to be found among the vandas, and these are grown as much as the plentiful hybrids. This group also produces the beautiful blue colour so rare in orchids, and one species in particular, Vanda caerulea, is the parent of the many blue hybrids now available. The best of these is Vanda Rothschildiana, that is greatly sought after for its unusual colour. Other colours scattered among the vandas include pink, yellow and brown. The flowers are generally spotted, veined or tessellated. New hybrids are continuously being raised from seed, bringing in other genera closely related to increase the colour variations still further.

A selection of species

So far we have mentioned most of the popular genera among orchids, dwelling on the types that are being greatly hybridized. There remain many species that are grown for their individual beauty and appeal, and that are ideal for the amateur grower who has only limited space available. The following species have been chosen for their compact habit of growth, ease of culture and free-flowering habit. All are cool-growing and recommended for the beginner, being showy and interesting and are sure to whet the appetite and encourage the new grower to seek further knowledge of these fascinating plants.

Brassia verrucosa

The ‘spider’ orchid. It has large flowers on gracefully-arching sprays. Sepals and petals are long and narrow, green-spotted with brown. From Honduras.

Coelogyne ochracea

Sweet-scented sprays of small, delightful flowers. It is snow-white, the lip marked with yellow and orange. Spring-flowering. From India.

Cymbidium devonianum

Miniature flowers, reddish-green on long, pendant sprays, with a dull purple lip. Early spring-flowering. From India.

Dendrobium infundibulum

Large, pure white flowers, in clusters from the top of the bulb, with a deep yellow stain at the throat. Early summer-flowering. From India.

Dendrobium nobile

Attractive rose-pink and white flowers, the length of the cane, with a white lip and a large, deep maroon blotch in the centre. From India.

lycasta cruenta orchidEncyclia cochleata

Upright spray of curious dark-green and dark-purple flowers with lip held uppermost. Common name is ‘cockle-shell’ orchid. Blooms for long periods during spring and summer. Comes from Honduras and Guatemala.

Laelia anceps

Tall flower spikes that average four blooms. Large, showy and delicate mauve with lip richly-coloured and marked yellow in the throat. Autumn-to winter-flowering. From Mexico.

Lycaste cruenta

Bright golden-yellow flowers. Three-cornered in appearance. Single, fragrant blooms. Spring-flowering. From Guatemala.

Odontoglossum grande

‘Tiger’ orchid. Large, richly-coloured flowers in yellow with chestnut-brown bars and a shell-shaped lip in creamy-yellow and brown. Autumn-flowering. From Guatemala.

Paphiopedilum hirsutissimum

Large single bloom, very long-lasting. Petals pale green tapering to bold pink, heavily dotted with purple. Pouch, light green. Spring-flowering. From India.

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12. July 2011 by admin
Categories: Greenhouse Gardening, Orchids, Orchids | Tags: , , , , , , | Comments Off on Growing Orchids in the Hot Greenhouse

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