how to disinfect and clean a greenhouse?

how to disinfect and clean a greenhouse?

We all know that Greenhouses are wonderful things that allow us to keep on growing when the conditions outside wouldn’t normally permit it. However, it’s the conditions inside your greenhouse that we are talking about today.

Thoroughly tidying, disinfecting, and cleaning your greenhouse is something that needs to become part of your maintenance schedule if you hope to keep pests and diseases at bay, and help your plants and crops grow unimpeded.

Now, I know that the idea of cleaning out a greenhouse probably isn’t at the top of people’s ‘things I love to do’ lists, and even the thought of it is enough for many to put it off again and again, but if neglected for too long, you will end up with all kinds of problems in there.

So, we’ve established how important it is to disinfect and clean your greenhouse, and in this article, we are going to tell you when, and how, to do it for the best results. Cleaning your greenhouse is one of those things that actually seem much worse in your mind than when you do it, and the end results leave you feeling very satisfied.

So, follow these tips and make your greenhouse a spotless eutopia for your plants, rather than a pest and disease-infested hellhole, and who knows? You might even make a new friend while you’re at it like this person-

When should I disinfect and clean my greenhouse?

Different people have varying opinions on this, but I think most would agree that twice a year is the bare minimum, and this should be carried out in Spring and Autumn.

Autumn is a particularly important time to have a good clean of your greenhouse as winter conditions usually mean less activity in there from you, and that leads to mites, algae, and other unwanted things taking up residence.

If you are growing things like tomatoes, or other summer crops, you might want to disinfect and clean your greenhouse in winter instead of Autumn, just after you’ve cleared the crops.

How long will it take to clean my greenhouse?

Cleaning and disinfecting your greenhouse aren’t things you want to rush and do half-cocked, or you’ll just invite more problems. It’s much better to take your time and do a thorough job, ensuring that any risks to your plants have been dealt with.

I always put three days aside for cleaning my greenhouse. The first one is to clear everything out from the inside and decide what I’m going to keep, and what will go in the bin and be replaced. I also sweep and vacuum the floor on this day too.

The second day, I spend washing down surfaces and cleaning all the panes of glass, making sure to remove any algae build-up around them, and even removing panes to clean out the frames if I feel it is needed.

The third day is used to disinfect the greenhouse from top to bottom. That includes all surfaces such as tables and benches, and also containers. Also on this day, I clean and disinfect the tools that I use in the greenhouse to prevent any contamination.

Here’s a video of a lady getting ready to clean her greenhouse that you might be interested in-

What will I need to disinfect and clean my greenhouse?

You don’t need to spend a lot of money to clean your greenhouse, and most of the things you need you will probably already have around the house. Here’s a little list that should see you through the task-

· Bucket and soapy water
· Sponges (preferably with a good-sized handle), scouring pad or sponge, and squeegee
· Cloths or rags
· Bleach or other disinfectants
· Hosepipe or pressure washer
· Glass cleaner (optional)
· Sweeping brush, small hand brush & pan.
· vacuum

How to clean and disinfect a greenhouse: step-by-step

1. The first step is probably the most labour intensive as it involves clearing out the contents of your greenhouse. Not only does this make the cleaning process easier, but it removes contaminated or infected items from the area. If you have fixed surfaces or large tables or benches that aren’t easily removed, they will have to stay but you will need to give them a really good cleaning and disinfecting later.

As you’re removing things, you need to decide on what to keep and what to throw away. It is my advice that unless you really need to keep something, you should probably bin it. This will reduce the risk of returning disease and pests back into your greenhouse once it’s been cleaned.

When you’ve cleared as much as you can, don’t forget to switch off any electricity supply, or if this isn’t possible, use tape or something else to cover any sockets. If you have electrical devices like heaters that are fitted in and can’t be removed, you’ll need to cover them too.

For you guys who don’t have electricity in your greenhouse but are interested in the idea, heres’ a video for your viewing pleasure-


2. Grab your hand brush and sweep any debris from your frames, and tables, or benches that you couldn’t remove. Then use the sweeping brush to clear as much of the floor as you can, before using a vacuum to pick up anything you couldn’t get with the brush. Don’t worry if there is thick grime, moss, or algae, stuck on a concrete floor as you can use a pressure washer, or just good old-fashioned scrubbing, to remove that the following day.

With the floor swept, you should now turn your attention to your gutters and clear them of things like leaves and twigs. Again, if there is thick dirt or unwanted organic matter built up in there, you can last it clean with a pressure washer. Alternatively, you might feel the need to replace your guttering, but this is usually not necessary. Although, you might just want to put some new shiny stuff on in this picture-

You can call it a day after accomplishing all of this and get ready for day two, which will be predominantly taken up washing surfaces.

3. After you’ve had a good night’s sleep, you’ll want to prepare a bucket of soapy water, grab some rage, sponges, and a squeegee, as well as a garden hose, and get started on the outside of the greenhouse. If you own a pressure washer, you should start with that and blast the gutters clean, and give the floor inside a good cleaning if necessary.

After you’ve cleaned the outside, step inside and do the same for the panes, surfaces, and pretty much everything you can see. Check for algae build-up in between the panes and the frames, and make sure you clean them out. This might require you to use something to wedge into the gap while you work, or even remove the pane if it is not too risky or difficult.

Once everything has been washed with soap and water, I use a glass cleaner to really give it that finishing touch. My thinking is that the cleaner the glass, the greater the amount of light that can come in, so it’s worth the extra work.

Make sure that you have fully rinsed off any soapy residue as it can reduce the effectiveness of disinfectants that we will be using on day three. Also, if you noticed that any of your window panes were cracked or chipped, you should replace them or small insects will be able to get inside.

Here’s a strangely satisfying time-lapse video of someone using a petrol pressure washer to clean up a really old and dirty greenhouse, and if yours is in the same state, it might be a good idea to invest in one of these tools.

4. On the third and final day, you’ll need to prepare a disinfectant. The easiest and cheapest one is simply to mix bleach and water, but there are also plenty of products out there that are designed for just this kind of job.

Wash all the windows, frames, and any objects you couldn’t remove such as heaters or fans with your disinfectant solution, and pay particular attention to any wooden surfaces as they are often breeding grounds for pests. It is also a good idea to treat any wood with horticultural oil.

After you’ve finished disinfecting the greenhouse, you need to do the same to any pots or other items that will be returning. If you are returning containers, not only should they be fully disinfected, but you should have removed and replaced the soil in them too, or all your hard work will have been for nothing. Likewise, tools need to be disinfected with either a bleach solution or alcohol.

If you’ve followed all these steps, you should now have a very clean, fully disinfected, and safe, greenhouse for you to start planting and growing in again. It might seem like a lot of work, but believe me when I say that it will greatly reduce the risk of your plants and crops getting infected, and all that extra sunlight getting through your newly cleaned windows will help them flourish.

About Terry Smith

I’m Terry Smith from, a professional landscape designer, hobbyist gardener, and barbecue fanatic with 20 years experience building and restoring. So as you go through my site you'll watch me document some of the professional garden installs I make as well as the major projects I take on at home. While sharing those experiences and guiding you, I'll be recommending some great tools I use to enable this along the way so you can really buy in confidence. Always feel free to pop me a message:

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