Tip 3: Manage Your Greenhouse Climate

Managing the climate of a greenhouse is about providing the plants with the right conditions for growth, flowering and fruiting. What you need to do will therefore depend on the kind of plants you are growing and the stage they have reached in their life cycle.

Not all plants need exactly the same conditions so the kind of climate will depend on what you plan to grow in you greenhouse. Some will need high temperatures and high humidity in the greenhouse. Others will require slightly cooler conditions in the greenhouse.

It is often possible to reach a compromise and provide conditions that will suit most of your plants most of the time. You will not be able to provide optimum conditions for all the plants in your greenhouse. But by choosing plants that like similar conditions you will achieve acceptable results.

Majority of our customers see themselves as being amateur greenhouse growers and therefore many have had to compromise. Some of our customers who are dedicated to a particular species have had to make some hard choices. It may be necessary to sacrifice variety for quality. If your greenhouse is devoted to orchids and only orchids you can provide the best climatic conditions. If you want to grow other types of plant we suggest you consider purchasing another greenhouse to keep them separate.

For most gardeners such hard decisions are not necessary. It is possible to provide a climate that will suit many plants to some extent. You may also find that you can partition off part of the greenhouse to create a microclimate. Part of the greenhouse can then have a climate that is hotter or more humid than the rest.

In higher temperate parts of Australia where there is a relatively long growing season it is often possible to have an unheated greenhouse. An unheated greenhouse relies on the sun’s rays and the residual heat stored in the ground to create a climate that is warmer than the outside environment. This is adequate for raising seeds and for growing vegetables such as tomatoes in the summer.

Regulating the climate in an unheated greenhouse is mainly a matter of making sure that there is enough humidity to avoid pests and enough ventilation to avoid mildew. The lower the Temperature the lower the humidity should be. Air cannot hold much moisture at low temperature and rot will result if the greenhouse is not properly ventilated.

Providing some heat will allow a longer growing season. If the greenhouse is heated in the winter it will be possible to provide a frost-free space for tender plants that live outdoors in the summer. A small amount of heat will provide a greenhouse climate in which some salads can be grown all year round.