How Do I Prevent My Greenhouse From Steaming Up?

Did you provide constant air circulation in your greenhouse during spring and fall?

Did you provide a good heating system inside your greenhouse?

Did you make a good drainage system inside your greenhouse?

Did you space your plants so that their foliage isn't touching?

Providing constant air circulation in spring and fall helps to stop condensation on leaves in a greenhouse. The best way is to heat a greenhouse in the evening for a short period when the ventilation fan is running. Ventilation ensures that dry air from outside enters greenhouse structures and exchanges with moist air. Greenhouse with natural ventilation can take up to 30 minutes or longer to exchange air.

Combination of heating and ventilation lowers down the relative humidity in a greenhouse. Ventilation lets in dry air from outside and exchanges it with the moist air inside the greenhouse. In the meantime, the heating system raises the temperature of the dry outdoor air and also expands air to hold more moisture, so it prevents condensation from forming.

Good greenhouse floor and drainage prevents the formation of standing water which evaporates and increases the amount of moisture in the air. Moreover, if the condensation forms, the water droplets will go down from the greenhouse glazing and frame and simply flow away through drainage.

Sufficient plant spacing improves air circulation at the plant level. The highest relative humidity is inside plant canopies, the above-ground portion of a crop. Plants produce moisture during transpiration and if there is not enough space it gets trapped. That also leads to insufficient air movement.

Adequate watering practice helps to prevent condensation in your greenhouse structure. Water your plants just enough so excess water doesn’t stay on the floor. Also, it is very important to water plants early in the morning so they can dry before evening.