How can you most effectively monitor and regulate the temperature in a greenhouse when it’s cold out? Heaters are the most important part, but they alone can’t do everything, especially when different plants require different conditions. Furthermore, heaters alone will dry out the air when most greenhouse conditions require a moist environment. Here are seven ways to help your heaters out and to cut back on energy costs:

1. Remember to pack your greenhouse space relatively tightly. The closer plants are together, the more they help conserve heat and moisture. The emptier a greenhouse is, the less able it is to retain its own environment. You’re essentially separating a thermal mass that will do some of the work for you. If you’re only using half the space in your greenhouse, don’t spread everything out. Consider setting the plants closer together and partitioning the empty half off. Heavy plastic sheets are good for this, and this will help you save on heating costs.
2. Water is a remarkably good heat sink. Large, open containers of room temperature water on the floor will help to regulate the temperature better, absorbing excess heat during the day and releasing it at night. Evaporation will also help to keep moisture in the air. Just remember to keep your containers away from anything electrical, and change the water out regularly.
3. Try using wooden boxes instead of metal or plastic ones. These will not sap heat from the soil and planters as quickly as many artificial materials.
4. Use heating pads under the soil and planters, particularly in germination areas. Always ensure that your set-up is electrically safe.
5. There is, of course, a risk of overheating your plants and the soil they’re in. Use a humidity and temperature probe to monitor the conditions of the soil itself. Adjust the intensity of your heating set-up accordingly.
6. A few glass panels over particular plants that require higher temperatures can help trap heat and moisture. This is an easy way to adjust one plant’s environment without adjusting the environment of the plant next to it.
7. Use a hygrometer to help monitor a variety of dew-point and humidity conditions for your greenhouse. The more comfortable a range you’re able to keep your greenhouse for your plants, the healthier, more nutritious, and more beautiful they will be.