How To Keep Plants In Greenhouse From Growing Mold

How To Keep Plants In Greenhouse From Growing Mold

Wondering of the ways on how to keep plants in greenhouse from growing mold? Well, you’re in luck! Mold grows easily in warm and moist environments.

You’ll have to consider the amount of water, humidity, spacing, airflow and ventilation of your greenhouse. These factors are key to long term growing success in greenhouses.

Sadly, fungi thrive in encased areas such as greenhouses. This makes their growth inevitable. But, with the right knowledge, proper setup, and consistent practice of cleanliness and maintenance, you too can create a mold-free environment.

In this article, you’ll understand how to keep plants in greenhouse from growing mold. Just read more to find out!


Ways To Prevent Plants From Growing Mold In Your Greenhouse

You may be wondering how to keep plants in greenhouse from growing mold. Don’t be, because we’ll help you how. Every step is crucial so make sure you understand everything.


#1 Identifying the signs

Before prevention is inspection, you can’t prevent what you don’t know. Two types of molds are commonly found on plants:

  • White mold – white and wool-like growth on the surface of the soil. This is caused by damp conditions from over-watering and limited ventilation.
  • Powdery mildew – white dusty layer on the leaves and stems of your plants, resembling flour. It can become grey as time passes. This affects photosynthesis and plant growth.

Regularly checking on the leaves’ underside, where you’ll see the most apparent signs of Mold, will help you confirm if your prevention worked. To remove Mold, use hydrogen peroxide or vinegar solutions since they’re safer for plants.


#2 Water and humidity

One of the most crucial parts of keeping your greenhouse mold-free is avoiding water accumulation. Be sure to remove stagnant water from the plant foliage, soil, as well as from other surfaces inside of the greenhouse

Remember not to over-water your plants. If there’s too much for the plants to drink up, the mold will kindly offer to do so. Our suggestion would be an irrigation system. For example, drip irrigation which only drips water on the roots of the plants.

Day time is better than nighttime, if you plan to water your plants. Photosynthesis is responsible for using up that water during day. Nighttime, however, has none and thus mold flourishes on the excess water left to sit overnight.

Molds survive best near 85% humidity. Try to keep the humidity level as low as possible while still preserving the needs of the plants. A way to control this is by installing a dehumidifier and preventing the humidity from getting too high.

A greenhouse thermometer and hygrometer would be a good investment for this, as well. They’ll be sure to monitor temperature and humidity levels all day. If needed, grab a greenhouse heater.


#3 Ventilation and air purification

Air circulation is critical to prevent mold from growing. Low airflow leads to an increase in humidity levels, which stimulates spores to spread. Natural airflow is created with the wind and circulation.

Opening the vents and adding fans will keep the air moving. Ventilation helps to regulate temperature and keeps fresh air coming in and dirty air going out. Fans increase airflow, install it in the front or back of the greenhouse to draw warm air through, and then blow it outside.

A dehumidifier or air conditioning unit may also facilitate air movement and decrease humidity in humid locations.

If molds appeared in your greenhouse once, pesky microscopic spores are probably still in the air. Setting up an air purifier specifically for mold spores will ensure complete eradication of those spores. The clean and dry air should keep new cultures from forming out of the old ones.


#4 Spacing

Give your plants some room to breathe. Spacing will prevent the mold from spreading to neighboring plants. This also promotes better air flow and sun exposure. Packed plants have poor air flow which leads to higher humidity levels.

Make sure not to let leaves of various plants become entangled, as well as regularly clipping and thinning plants when they start to look overgrown.

Moreover, treating packed plants affected by mold is harder. Spraying and dusting the thick foliage will be taxing to effectively penetrate. It can get tedious, so to avoid it you need to start thinning your plants.


#5 Cleanliness

Cleanliness and general maintenance of your greenhouse will take you a long way. Dirt or water buildup in your tools is a fatal error. Mold is sneaky and will find a way into your soil then plants through them. So make sure to clean and wipe them after use.

If mold does succeed in its infiltration, eliminate all infected soil or plant matter, as well as, meticulously disinfecting any breached surface. This is to avoid regrowth of mold.



In conclusion, to prevent plants from growing mold in your greenhouse, keep general humidity below 85%, avoid over-watering, and be sure to give space and delicate plants for good air circulation adequately.

Vents and fans help keep temperature and humidity. General cleanliness and maintenance will go a long way in keeping your greenhouse mold-free.

Hopefully, you’ve learned how to keep plants in greenhouse from growing mold. Have a great day!

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