Greenhouses come in a variety of forms. Some greenhouses are heated, others are cool. Some greenhouses are large, while others are small. Whichever greenhouse you have, you have more control over the environment for your plants than if your garden were outside. The type of soil and amount of water provided for plants are in your control, allowing for a variety of options.
Eggplant, also called aubergine, does well in warm greenhouses. The seeds of this plant, related to the pepper and tomato, should be soaked in warm water to help them germinate. When seedlings reach 4 inches tall, they should be planted into 8-inch pots and placed into the greenhouse.
Tomatoes are a classic greenhouse vegetable. There are many varieties of tomato plant, but the upright cordon kind, rather than bushier types of plant, are best suited for greenhouses. Place a cane or trellis to support vines and shoots. To promote a higher yield, provide regular high-potassium feeds. Sunbaby and Shirley varieties of tomato are very well-suited for greenhouses and produce fruits that are said to have tasty flavour.
The kind of greenhouse you have matters when it comes to decorative plants. There is a wider selection if you have a heated greenhouse. Gloriosa, a climbing plant with orange flowers, the strong fragrant bloom of gardenia and the beautiful variegated foliage of peperomia are all suitable plants for a heated greenhouse. Begonias, dracaenas, cyclamen and poinsettias may also be grown in greenhouses heated to temperatures between 10 degrees C and 15.6 degrees Celsius.
In cooler greenhouses, hedychiums, which have spidery-looking flowers and a strong fragrance, are a good choice for decoration. Gloxinias, with red, white or purple blooms, will also work in cooler greenhouse environments, as will camellias. The interestingly named voodoo lily is also an option.
Given the limited space and structure of greenhouses, climbing plants and vines are great choices given their ability to grow upwards, across, and hang down. Do research before selecting a climbing plant, as some of them require a constant or minimum temperature to survive. Jasmine plants offer star-shaped flowers that have a wonderful fragrance. However, they must have an ambient temperature around 15.6 degrees Celsius to flower. Clematic armandii are evergreen plants that will grow in your greenhouse, although they may need pruning to keep them in check. This evergreen has the dual advantages of insulation in the winter and shade in the summer.