The greenhouse will need to be shaded for about half the year. Shading is important to prevent the orchids from being burnt by the sun; it also assists in keeping the temperature down. It will become necessary to shade the greenhouse as soon as the sun begins to gain power, in early spring.
Terrestrial orchids vary in their soil requirements. Some prefer grassy meadows with a well-drained subsoil, others like peaty bogs that are permanently wet, while in the tropics many live on the open savanna plains where, during the dry season, they become completely dehydrated because of the shortage of moisture in the soil. Their rhizomes may be either just below the surface or very deep, depending on the species. Their root system may only penetrate the mossy soil covering or push deep into the subsoil in the search for permanent moisture.
At the height of summer, you can repeat this again towards late afternoon. As evening falls, all surplus water will have dried up, but as the temperature drops, the humidity will rise naturally and remain at a good level for most of the night.
During the summer, this will be good for your orchids, but as winter approaches, together with lower temperatures, you will not want to add further humidity by damping down after midday. In winter, it is necessary to damp down the floor and between the orchids only once a day, in the morning.
Although expensive and time-consuming to prepare, this formed an ideal compost for over 50 years. One of the reasons that orchids rooted so well in it was thought to be the living moss, which formed a green growing at on the surface. However, once the rooting of orchids became fashionable, it killed the moss, causing the compost to deteriorate and decompose so a soggy state. The search was on for soniething better. Bark Compost i the necessary requirements for a new compost (growing medium) were found the bark of the American redwood cedar, although in Britain, where plantations of Corsican and Scots pine were being felled, the bark from these trees proved a good substitute.
The bark compost was much cheaper to produce and easier to handle than the old moss and fibre mixture, and today it is sold all over the world specifically for orchids. It is produced from locally felled trees and supplied through specialist nurseries and larger garden centres. It comes in graded pieces, suitable for seedlings or mature plants. It should not be confused with the bark sold by garden centres for mulching flowerbeds.
Orchid bark is slow to decompose and will not break down when fertilizer is added. It will remain in a good state for several years, slowly releasing its nutrients. It retains just the right amount of moisture for the roots, but without remaining too wet after watering. It can be used on its own or other materials can be mixed with it as required. If you find that your orchids are suffering from dryness, and you have difficulty in keeping the bark compost (growing medium) sufficiently moist, add about a third of sphagnum moss or other fibrous peat to the mix.
A peat substitute will do as well, although it may need sieving to remove the finer particles. This will provide a slightly wetter mix, which can be an advantage if you cannot attend to your orchids as often as you would like. To this basic mix you can add a small percentage of charcoal, which will ensure that the compost stays "sweet" and does not become soured. Use only granulated horticultural charcoal as supplied by specialist nurseries or garden centres. This is not the same as barbecue charcoal, which has been treated to burn slowly and is unsuitable for orchids. - 15266
Terrestrial orchids vary in their soil requirements. Some prefer grassy meadows with a well-drained subsoil, others like peaty bogs that are permanently wet, while in the tropics many live on the open savanna plains where, during the dry season, they become completely dehydrated because of the shortage of moisture in the soil. Their rhizomes may be either just below the surface or very deep, depending on the species. Their root system may only penetrate the mossy soil covering or push deep into the subsoil in the search for permanent moisture.
At the height of summer, you can repeat this again towards late afternoon. As evening falls, all surplus water will have dried up, but as the temperature drops, the humidity will rise naturally and remain at a good level for most of the night.
During the summer, this will be good for your orchids, but as winter approaches, together with lower temperatures, you will not want to add further humidity by damping down after midday. In winter, it is necessary to damp down the floor and between the orchids only once a day, in the morning.
Although expensive and time-consuming to prepare, this formed an ideal compost for over 50 years. One of the reasons that orchids rooted so well in it was thought to be the living moss, which formed a green growing at on the surface. However, once the rooting of orchids became fashionable, it killed the moss, causing the compost to deteriorate and decompose so a soggy state. The search was on for soniething better. Bark Compost i the necessary requirements for a new compost (growing medium) were found the bark of the American redwood cedar, although in Britain, where plantations of Corsican and Scots pine were being felled, the bark from these trees proved a good substitute.
The bark compost was much cheaper to produce and easier to handle than the old moss and fibre mixture, and today it is sold all over the world specifically for orchids. It is produced from locally felled trees and supplied through specialist nurseries and larger garden centres. It comes in graded pieces, suitable for seedlings or mature plants. It should not be confused with the bark sold by garden centres for mulching flowerbeds.
Orchid bark is slow to decompose and will not break down when fertilizer is added. It will remain in a good state for several years, slowly releasing its nutrients. It retains just the right amount of moisture for the roots, but without remaining too wet after watering. It can be used on its own or other materials can be mixed with it as required. If you find that your orchids are suffering from dryness, and you have difficulty in keeping the bark compost (growing medium) sufficiently moist, add about a third of sphagnum moss or other fibrous peat to the mix.
A peat substitute will do as well, although it may need sieving to remove the finer particles. This will provide a slightly wetter mix, which can be an advantage if you cannot attend to your orchids as often as you would like. To this basic mix you can add a small percentage of charcoal, which will ensure that the compost stays "sweet" and does not become soured. Use only granulated horticultural charcoal as supplied by specialist nurseries or garden centres. This is not the same as barbecue charcoal, which has been treated to burn slowly and is unsuitable for orchids. - 15266
