A greenhouse is a closed plastic or glass-roofed enclosure where plants are cultivated in a controlled environment. The temperature and humidity are regulated with the help of sensors to achieve maximum yield from the plants. Different types of plants including vegetables, fruits, flowers and tobacco grow well in a greenhouse---and some gardeners use the bumblebee for pollinating purposes.
Tomatoes are the most popular variety of plants for the greenhouse. Tomatoes grow and flourish in an environment where light, water and warmth are plentiful. Prevent tomato plants from collapsing under their own weight by using a bamboo cane or tying the plants up with twine at two or more places for support. To achieve more yield, cut young shoots to divert all energy of the plant in producing the fruits. Yield can also be increased by providing the plants a potash-rich manure or fertilizer.
An environment required for proper growth of orchids is easily created in a greenhouse. Depending on the type of orchid, the temperature can be adjusted to a higher or a lower level. Orchids require adequate sunlight, and hence the greenhouse should be built accordingly. The Vanda variety of orchid needs a hot greenhouse, while the phalaenopsis thrives at lower temperatures. Since the plants' environment is controlled according to specific requirements, orchids are often cultivated in greenhouses year round.
Citrus plants grown in a greenhouse live longer and have an increased yield. Due to the accumulation of carbon dioxide in the greenhouse, citrus plants grow faster. Maintaining 10 to 25 percent higher humidity also helps in achieving a higher yield.
Lemon grass is a natural aromatic herb is used for aesthetic purposes and is also used as a mosquito repellent. A native of tropical regions, it usually grows in clusters and grows well with mixed soil containing two parts peat moss and two parts clay, with one fraction perlite (amorphous glass) or sand. This plant requires damp soil with an excellent drainage system.
Winter- and spring-season blooming roses are grown well in a cold greenhouse. Roses require abundant water during the summer season as, at this time of year, the plant develops new shoots. In the winter months, roses' water requirement is low. Long-stemmed roses, which fetch a good price, can be grown in greenhouses in rich, well-draining, all-purpose potting soil, with a moderate temperature of 60 to 70 degrees F. The humidity must be kept at 60 to 70 percent, with an abundant supply of carbon dioxide.