The vast majority of British gardeners use their greenhouses for growing vegetables and starting off flowering plants for transfer into the garden. Some also use their greenhouses for growing more exotic plants or for flowers to be cut and displayed in the home. This is because the greenhouse offers a controllable environment and one which makes the most of the fleeting appearance of the British summer. However, knowing what to do in your greenhouse and when is an essential part of successful gardening.
Greenhouses are the perfect environment for starting vegetables such as leeks and cabbages for an earlier and more secure harvest. Grown from February onwards, these plants will be strong and robust enough to go straight out after the last frost, saving you a good three months of growing time. Other plants, like French beans, tomatoes, cucumbers, peppers and aubergines, are usually grown throughout the summer under glass. In autumn, salad crops such as lettuce and Calabrese will continue to grow indoors after their outdoor relatives have died off. You can also keep harvesting tomatoes into the autumn, and many people bring their tomatoes in after September to gain more fruit.
Growing Flowers and Plants
While it’s true that most greenhouses become food factories in the summer months, before they get too crowded most gardeners use them to bring on their garden plants. Some seeds can be grown all year round in a greenhouse, but most people start them off in the pre-spring to ensure flowering before the first day of summer. The best way to ensure a good stock of bedding plants by summer is by planting seeds and rooting cuttings under glass. This is an important function of the greenhouse. However, after late May, most of these plants will leave for the garden.
Not all plants do leave the greenhouse, and there are advantages to keeping flowering plants inside throughout the summer months. While indoor growing can provide the perfect environment, it can also disturb some elements of nature – namely pollination. Vegetables such as courgettes and cucumbers require constant pollination, and the best way to achieve this is with bees. Tall flowering plants such as asters, Echinacea and ornamental sunflowers attract the bees in, and after they’ve visited once, they’ll tell their friends. Pulling your garden’s eco-system into the greenhouse is also important for ensuring predator insects are around to fight off pests.
But the most important part of greenhouse gardening success is in the planning. Before you start growing, measure and sketch your greenhouse and decide what will go where and when. You’ll need to time planting-out with growing-on and have a fairly good idea of the size of mature plants. If you find you do have space free between phases, stick in a crop of salad leaves in the late spring and early autumn or use up space with herbs such as basil, lemongrass and chives.