Tricks to beat summer overheating in the greenhouse

It’s been a hot summer her in Portland, Oregon, which reminds us to have a plan for battling the scorching heat and ensuring your garden can thrive. There are a number of methods for combating the heat, but we’ve picked our favorites to share with you.

Gravel floor and jalousie windowr

A gravel floor that can be wet down and jalousie windows are two good heat-busters for a summer greenhouse.

Methods for getting extra moisture in the greenhouse vary based on the amount of time and money available. Gravel is a convenient floor for your greenhouse and in the hot summer months, it can help provide extra humidity. Simply wet down the gravel at the beginning of the day and as the day goes along, the water will evaporate to keep the greenhouse cool.

If you don’t have the time or inclination to wet the floor once a day and are willing to spend a little more money, an automatic fogger can solve your problems. An automated misting system, such as our Oregon mist fogger, can be set up to turn on and off based on the humidity levels in the greenhouse.

Simple misting systems are also available from stores such as Home Depot or Lowes, and are easily attached to a wood framed greenhouse such as ours.  


Vents are one of the oldest methods for preventing overheating by allowing cool air circulation to pass through the greenhouse. Ideally there should be roof vents to let hot air out the top of the greenhouse and vents in the basewall, to let in cooler air down low. For those with greenhouse base walls that do not have vents, louvered, or Jalousie, windows can be added to the glass walls. Roof vents can be manually opened or automated (see our solar powered Bayliss Autovent openers) to open when the greenhouse reaches a certain temperature.

french door tudor with shade cloth 14 x 14

Shade cloth prevents excess heating and sun exposure during long sunny days.

Until someone makes an Aloe Vera for plants, preventing sunburn is the best thing we can do. Shade cloth, which attaches to the outside of the greenhouse, prevents excess heating and sun exposure during long sunny days. Different density cloths are available, depending on your sunlight levels and the sensitivity of your plants.