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Keeping Your Greenhouse Cool
It’s the dog days of summer and you need to figure out how you’re going to be keeping your greenhouse cool. The sun sure does get hot! And it heats a greenhouse very well. This is great for the winter, but not so much for the summer.
Have you ever seen what extreme heat and humidity can do to a plant? The leaves literally burn and turn black. Not so great if you are trying to feed a family. When your plants die, you are out of production.
Here are a few tips to keep that greenhouse from overheating during these long hot sunny days.
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Monitor your Heat
The first thing you should do when maintaining your greenhouse is to monitor your temperatures throughout the day. Also keep an eye on it through the seasons. This will help you determine what your biggest need is for temperature regulation. Keeping a log to watch for temperature trends is a great aid in this.
Some areas have harsh cold winters that require heating and others have long, dry, hot summers that will require cooling. And then other areas have swings between the two. You could find yourself balancing between the two extremes depending on the time of the year.
Unless your greenhouse is close to your main house, temperature monitoring is not so easy. I had set up a remote weather station so I could look at a screen to determine temperatures in both the greenhouse and the garden. As life returned to normal and I returned to the office I needed something a bit more sophisticated. I needed something that would allow me to monitor my greenhouse from work, which is where this came in handy.
Good Ventilation
The first thing to look for when cooling a greenhouse is ventilation. Heat rises, and if you can’t vent it out, the whole greenhouse heats up. Adding a vent fan near the roof helps heat to escape. Adding a fan helps even more because you will actually be able to push the heat out.
Natural ventilation is handy until there is no breeze to help you out. Moving air helps to keep plants cool in much the same way that we cool ourselves by sweating. Water takes the heat off of the plant as it evaporates.
Plants though, lose water through their leaves. When there is not enough water remaining, their stomata close and they can no longer let out water for cooling purposes. Make sure your plants have plenty of water to prevent this from happening.
Use Evaporative Cooling
Most would know this by the name “Swamp cooler”. It works by pushing air through a wet pad to humidify and cool the air that comes out of it. This may not be the best solution if you live in a humid area. Great if you are in an arid location as it is cost effective and can lower temperatures 10-20 degrees fairly quickly.
Utilize a Misting System
If a fan isn’t enough, and a swamp cooler isn’t feasible, then a misting system might do the trick. Thin hoses run throughout the greenhouse and spray a fine mist of water into the air. This mist evaporates taking the heat away from the confined greenhouse.
Create Shade
This goes back to your original monitoring you did. Perhaps you chose a location that is just too sunny for the summer. If you can physically move your greenhouse to a shaded location, this may help out a great deal. Be sure to position your greenhouse where it won’t sustain any damage from falling limbs or other damage.
If you can’t move your greenhouse, try adding shade with some shade cloth. This is a fabric that blocks different amounts of light. The amount of shade produced depends on the thickness of the cloth. They provide up to 70% shade and can be easily installed inside, or over your greenhouse.
Use Your Plants
That evaporative cooling thing? Yeah, plans do this. Try using large leaves plants what have plenty of water to provide shade and evaporative cooling for your more sensitive plants.
Heat-loving plants such as squash and melons that like to climb can be used as a natural screen for your greenhouse. They will absorb the suns heat, transpire out water through their leaves and provide shade below them. Instead of misters, set up drip irrigation to keep these plants well hydrated to take full advantage of this feature.
Keep Plants Watered
Plants require water to keep their processes going. Not enough water and they literally can’t breathe because the openings on their leaves close up. This stops transpiration from happening and they wilt and die.
Making sure plants have enough water to transpire in the heat ensures that they won’t wither and die in the summer heat.
Keep it Wet
When all else fails, spray down everything but the plants and open up the doors. The water will absorb the heat from the greenhouse air, walkways, pots, and other surfaces and evaporate to remove the heat from the area. Propping open the doors allows fresh air to enter and hot air to escape.
Effectively Growing in Your Greenhouse
Greenhouses were designed to keep things warm. They were invented to grow tropical plants in colder climates. This becomes a problem in warmer climates where cooling is a necessity.
You can effectively cool off your greenhouse in the hot summer months quickly and easily. You can take the hands on approach or set up an automated system. Keep monitoring your growing conditions to know if your automatic system is actually working so you can intervene if needed.
For More Gardening and Greenhouse Tips
Check out these other great articles to keep growing all year-round:
15 Awesome Garden Layouts to Try This Year
Tomato Gardening Tips for a Great Harvest
15 Easy Garden Starting Tips to Get You Growing This Year
15 Expert Gardening Tips to Make Starting Your Garden a Success