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Cleaning greenhouse in autumn: how to clean it so that it is ready for the winter and spring!

Greenhouses are the perfect addition to any gardener’s garden, as they protect plants from extreme weather conditions and pests, while extending the growing season for plants like tomatoes. The warm, dry and pest-free conditions are ideal for seedlings and tender plants. However, if a greenhouse is not maintained and disinfected, it can do more harm than good. Cleaning greenhouses, whether glass or plastic, greatly improves growing conditions for plants. Removing mildew, moss and dirt allows more light in and keeps pests and diseases at bay. Discover how to clean your greenhouse in the fall below.

Why should you clean your greenhouse in the fall?

Why should you clean your greenhouse in autumn?

Whether they are made of glass, polycarbonate or polyethylene plastic, greenhouses benefit from regular cleaning and maintenance. Routine or annual cleaning is essential to prevent unwanted pests and diseases from entering. While plants thrive in this protected environment, it also provides the perfect conditions for pests to thrive or overwinter. Insects and mites overwinter in cracks and crevices, plant pathogens live on in the soil , algae grows in the pipes, and fungus gnats multiply on organic debris.

These are risks to any plants you hope to grow in the spring, and success requires a combination of plant removal, cleaning, disinfection and preparation. While these maintenance tasks should be performed regularly for year-round greenhouses, a fall cleaning at the end of the season is sufficient for seasonal greenhouses.

Cleaning greenhouse in autumn – instructions.

How to clean a greenhouse made of polycarbonate?

You will need:

  • A broom/vacuum cleaner
  • A bucket, washing-up liquid and water
  • A window squeegee
  • Natural household cleaning products
  • A sponge/soft cloth

Remove all objects

Start by removing the items from your greenhouse. Not only will this free up space for you to work with, but it will also allow you to remove any pests or diseases that may be underneath the items. If possible, do not bring them back inside during the cleaning process. Choose a day when the weather is dry. A breeze is also helpful as it will help dry out the greenhouse faster. If you prefer to spread the cleaning out over several days, plan the timing carefully.

Sweep the floor

Start at the bottom. You may find that the floor of your greenhouse is covered with dead plant material or even moss or algae. Sweep or vacuum the floor until all traces are removed. Pests and diseases can live in even the smallest areas.

Clean greenhouse in the fall – clean all surfaces and windows.

Cleaning greenhouse in autumn - clean all surfaces and windows

If your greenhouse has electricity, don’t forget to cover all outlets. Clean the surfaces in your greenhouse with water and dish soap, preferably a hot solution. Clean the windows of your greenhouse inside and out with a window squeegee. This will allow the plants to let in the maximum amount of light possible.

How to clean a polycarbonate greenhouse?

Polycarbonate windows are used in many greenhouses and to keep your greenhouse clean, you need to keep the individual windows clean as well. Since most polycarbonate products have UV protection, you can’t scrub them or use harsh abrasives when you wash them. Instead, start by washing each pane with a mild soap, such as dishwashing liquid, and water. When the water gets dirty, pour it out and replace it with clean water. Do this as often as necessary. Use a sponge or soft cloth, as anything else can damage the windows.

Disinfect your greenhouse.

Disinfect your greenhouse in autumn


Use a natural household cleaner to disinfect your greenhouse to remove any unwanted bacteria, fungus or mold. You can also start this work the next day.

There are many ways to get rid of algae, mildew and mold. If these coatings are on your plants, you can spray them with vinegar, let it sit for a few minutes, and then wipe off the solution. You can also mix a teaspoon of hydrogen peroxide with 250 ml of water and spray it on your plants. Leave the mixture on for ten minutes and then wipe it off with a cloth.

Use a hose

Spray your greenhouse with a hose and do it at high speed. This is a more effective alternative to scrubbing with a bucket of soap and water. The nooks and crannies in your greenhouse are an ideal hiding place for creepy crawlies, and the pressure from the hose will help flush them out. Metal frames are less attractive to pests, but wood is desirable, so be extra careful here.

Can you steam clean a greenhouse?

Can you clean a greenhouse with steam?

A good steam cleaner is all you need to make sure the inside of your greenhouse is as clean as it gets. The best part about steam cleaning your greenhouse is that most of these cleaners only use water and nothing else, so it’s an all-natural way to keep greenhouses clean at all times.

Don’t forget pots and accessories

Cleaning greenhouse in autumn - do not forget pots and accessories.


Wash all greenhouse accessories, including pots, trays and equipment, thoroughly with soapy water and soak in an oxygen bleach solution of 150 g oxygen bleach and 4 l water.