How to clean a greenhouse

How to Clean a Greenhouse | 13 Steps To The Best Growing Space

If you love your greenhouse and want it to be as productive as possible, it has to have a thorough cleaning at least once a year. If your greenhouse is seasonal, it will need to be cleaned at the end of the growing season; however, if you use it all year long, you’ll have to give your greenhouse a good cleaning perhaps twice a year.

Greenhouse cleaning is not a complex job but it is an important one and this article will help familiarize you with everything that needs to be done to have healthy, thriving plants or veggies all year long.

The main reason why you want to keep your greenhouse clean is to prevent pests, algae, and various diseases from affecting your plants growth and maybe even causing them to die. A greenhouse is a warm, muggy place because that is what’s good for the plants but this also means that greenhouses are more prone to many types of pests and diseases. 

Unfortunately, it takes more than just a little water to get your greenhouse as clean as it needs to be. In fact, you have to use the right products and perform the right steps regularly if you want your plants to thrive.

The good news is that once you learn the basics of cleaning a greenhouse, it becomes much easier for you from then on. It is the most important thing you can do if you want to keep pests, algae, and all types of diseases away from your plants. Ideally, you’ll make sure that the structure is thoroughly cleaned after each growing season. You need to become familiar with the proper way to do this, which products to utilize and which ones not to use, and what to look for to make sure that your plants are growing and thriving at all times.

Best Time of Year to Clean a Greenhouse

Most gardeners choose the wintertime to clean their greenhouses because this is when fewer things are blooming so having a greenhouse that has been thoroughly cleaned is a little easier. If you think about it, it makes sense. You have fewer jobs to do in the garden and it is generally cooler so you won’t have to worry about being uncomfortable if you end up being in there for a long time.

It may even be less humid and you’re therefore likely to have fewer pests that affect your plants and vegetation. In addition to all of this, the plants you do have won’t need a lot of work or maintenance and you likely won’t have to actually plant anything so cleaning and tidying up the greenhouse is much simpler and less complicated.

Of course, you’re not always able to clean your greenhouse only once a year so if it isn’t wintertime, your cleaning should be done in between each growing season of the plants that you wish to grow so that you’ll be fully prepared for the season that comes next. Remember once-a-year cleaning for seasonal greenhouses and a good washing several times a year for year-round greenhouses. Also, always pick a time when the greenhouse is a little more “empty” and when the temperatures are a little lower, like in the late afternoon/early evening hours. This makes the job a lot more comfortable on your part!

How to Clean a Greenhouse Roof

The first thing you need to know about cleaning the roof of a greenhouse is that it requires cleaning both the top of the roof and the bottom part, or the ceiling of your greenhouse. For the top (outside) of the roof, you can choose a telescopic roof-cleaning tool if you notice that the roof is especially dirty or even one of the many cleaning products made specifically for this purpose. Pay attention to the instructions that come with the product and you’ll be in good shape.

Clean greenhouse roof
Photo by Taylor Wilcox on Unsplash

You likely won’t have to rinse off the roof of your greenhouse after cleaning it because you can just let the rain do the job for you. With a cleaning product, however, it might be a good idea to rinse it off yourself if it hasn’t rained within three days of the time you used that product. Most of them have a maximum amount of time that the product should remain on your roof; afterward, the product will have to be washed off with a hose or brush. 

For the inside top portion of your greenhouse, one of the simplest tricks is to use a regular kitchen mop that has been wrung out so that it is damp and not wet. Then you can get up on a ladder and make sure that the top of the structure is cleaned thoroughly. You can try to find some fancier products that do the same thing but you might as well save yourself some money and use a mop instead. As you will see, a clean greenhouse is a more attractive and productive one, which gives you an incentive not to skip this important step.

How to Clean Between Greenhouse Glass

The good news about cleaning the glass windows in your greenhouse is that you can use a mild soap and some water to get the job done. Sometimes algae or moss will build up between the panes of glass that overlap. A simple way of cleaning the buildup of dirt is to gently wedge the glass panes apart with a little bit of paper. Next, use a watering can or hose to wash away the dirt. You will probably have to use a garden brush or toothbrush to scrub off the persistent dirt.

To make sure that you get the areas in between the glass panes as clear and sparkly as possible, you can use a special telescopic cleaning device with a squeegee at the tip. These tips often rotate 180 degrees, which makes them perfect for getting into every corner of the pane as well as the areas in between each pane so that nothing is overlooked or forgotten.

The glass in greenhouses has to be clean at all times. Otherwise, the sun’s rays won’t be able to get through;  therefore, your plants will not be able to grow and thrive as they should. You can also utilize cleaning products made for glass in your greenhouse but basic soap and water do the same thing in most cases and you may even save yourself some money in the meantime.

How Do You Get Rid of Mold and Algae in a Greenhouse?

Mold and algae can cause your plants to be less healthy and not produce flowers or veggies the way they should. A greenhouse cleaner made specifically for mold and algae is not difficult to find but you don’t have to find something made just for a greenhouse. Indeed, cleaning greenhouse mold, algae, pests, and anything else that gets in the way of growing healthy plants simply need the right products and supplies and nothing else.

Dirty greenhouse glass
Photo by Annie Spratt on Unsplash

There are other things that you can do to get rid of algae and mold. If these things are on your plants, you can douse the plants with vinegar, let it sit for a few minutes, then wipe off the solution.

As far as reducing the odds of getting mold and algae, you can take note of the temperature and humidity in the greenhouse and make sure that they are just right. You also need to be sure that there is enough air circulation through the greenhouse and keep it as clean as possible at all times.

There are also fungicides and other products that can help. You have to make certain that you use the products just as they are described in the instructions. Whether you choose over-the-counter products or products that you make yourself, keeping mold and algae away from your greenhouse as much as possible means that you are less likely to experience diseases that could force you to get rid of your greenhouse altogether and start all over again. Also, be careful with products containing hydrogen dioxide, or

How to Clean Your Pots and Trays

Believe it or not, the pots and trays found in greenhouses have special needs when it comes to staying clean. As a general rule, it’s a good idea to clean and disinfect your pots after every time you have used them. Otherwise, you may pass pests, diseases and viruses onto the next plant and not realize it. And don’t just rinse out your pots with soap and water. Instead, you need a proper disinfectant after you clean them because this will ensure that all pests, viruses and mold are removed completely.

The same goes for your trays. One of the things that you can use for both pots and trays is Q-salts, also known as quaternary ammonium chloride salts, which go by names such as Physan 20 and KleenGrow, among other products. Again, take your time reading the instructions,  use the products exactly as directed, and you’ll never have to worry about pots and trays spreading diseases from one plant to another.

And always clean your pots and trays well before disinfecting them. You’ll want to do that with a mild soap, such as dishwashing liquid, and some warm water. Once you know that they’re clean enough, you can move onto the disinfecting stage. You should never disinfect these items without making sure that they are cleaned well first. A solution of hydrogen dioxide (peroxide) does a great job, but again, make certain your flowers and veggies aren’t exposed to it too often.

Can You Steam Clean a Greenhouse?

A good steam cleaner is all you need to ensure that the inside of your greenhouse is as clean as it can be. So yes, it is possible to steam clean a greenhouse! The best part of having your greenhouse steam cleaned is that most of these cleaners work with water only and nothing else so it is an all-natural way to keep greenhouses super clean at all times. And most parts of your greenhouse can benefit from a good steam cleaner. Best of all, the cleaners are both inexpensive and easy to use. Since most of them let you adjust the pressure of the hose, you can steam clean even delicate items in your greenhouse, including the plants themselves.

Clean greenhouse

This doesn’t mean that you should be steaming everything that lives in the greenhouse. Some items, including herbs and some delicate and small flowers, won’t respond well to being steam cleaned even if you have the cleaner on the lowest setting. This is where you’ll need a little common sense because you can certainly ruin a plant or two if you’re not careful. For items such as glass, benches, and shelves, however, you can feel free to use your steam cleaner at full force.


But again, you’ll want to read the instructions carefully in case there are any restrictions or cautions that you need to pay attention to with that particular cleaner. Each steam cleaner is different but the biggest advantage they offer is that you can clean your greenhouse without using harsh chemicals or products that have unhealthy ingredients in them.

Finally, make sure that you allow air to circulate through the greenhouse after using your steam cleaner. Increasing ventilation will decrease the humidity of the environment.

Can You Pressure Wash a Greenhouse?

Pressure washers are not made for greenhouses but this doesn’t mean that you cannot use one in your own greenhouse. Greenhouses are usually made out of either glass or a polycarbonate plastic material and there are potential problems with using a pressure washer on both of these materials.

Once again, the pressure washer you buy will come with instructions and part of those instructions will include a list of things that you can and cannot clean with that particular washer. If the pressure washer you purchase says not to use it on glass, polycarbonate, or greenhouses in general, then you should heed that recommendation and avoid doing so.

If you do discover that you can use a pressure washer on your greenhouse, you should still use a fairly low setting and take caution not to work too quickly. Glass can shatter and polycarbonate can tear or rip but if you operate the washer properly and take the necessary precautions, this part of your greenhouse cleaning task should be productive and produce great results every time. You may even find that you like using this method to clean the structure because it is fast, simple, and extremely effective.

How to Clean an Aluminum Greenhouse Frame and Guttering

Effective greenhouse cleaning requires making sure that every single part of the structure is super clean, including the frame. To clean the frame, which is usually made out of aluminum, you can just follow a few simple steps. First of all, you should start by removing all of the plants and placing them outside. Then take a basic broom and brush off the frame — every inch of it — until it is clean and dirt-free. You have to make certain that the frame is clean and smooth so take a stiff brush if you need to and brush it along any bumps to remove debris and make certain that it’s smooth.

After all electrical outlets (if you have them) are covered up, place some warm soapy water in a bucket and scrub the entire frame with that solution, using the stiff brush the entire time. Work from the ground up for the best results. You also need to clean the frame both inside and out, using a long-handled squeegee or brush if you need to so that you stay safe while you’re working.

How to Clean Your Greenhouse Water Butt

Getting your water butt nice and clean isn’t difficult at all. The important thing to remember is that the water butt needs to be cleaned regularly so if you haven’t cleaned yours in a while, it may require some elbow grease to get it back to looking its best. The exterior should get a quick wipe on a regular basis and you should also occasionally empty the water butt completely and get all of the dirt, grime and debris out of it so that it can continue to work the way that it’s supposed to work.

Greenhouse water butt

As far as the cleaners themselves, most of these products come in either liquid or tablet form and they often have to stay in there a while in order to eliminate all of the algae, mold, and other harmful pests. Just be certain to follow the instructions because some of them have to remain in the water butt for up to two weeks in order to work properly. Of course, this is worth it in the end and is the only way to keep your water butt its cleanest from then on.

Why Fumigate a Greenhouse?

Fumigating a greenhouse is usually done to get rid of pests and insects that are harming the plants. If you’re spraying a bug killer on the plants inside of the greenhouse but you feel like you can’t keep up with all of the bugs you have, it may be time to fumigate. Fumigation products are super strong and are meant to kill all of the bugs that are in there as well as some that you didn’t even know you had. Think of fumigation as the ultimate in getting rid of bugs and other pests that can wreak havoc on your plants.

Fumigating also covers a very large area each time that the process is executed so it can work on large spaces in a much shorter period of time than using standard over-the-counter sprays and other products. This is yet another reason why people choose to fumigate their greenhouses:  they can kill a lot of creepy crawly things in a very short timeframe!

We would recommend using these at the end of the growing season.

How to Fumigate a Greenhouse

Once again, if spraying for bugs hasn’t produced the results that you were hoping for, you might want to purchase a good fumigation product. The way they work is simple. You must first remove all of your plants from your greenhouse and place them outside because the ingredients used in fumigation products will not only kill bugs but also living things such as vegetables or flowers. In most cases, after everything has been removed, you’ll just turn the product on;  as you leave, make sure that all doors and windows are closed as tightly as possible.

Fumigation products usually consist of a lot of smoke and that smoke consists of a lot of chemicals,  which is why your flowers and/or vegetables will be outside before you press that button. In many cases, the entire fumigation process takes several hours to complete and it’s important not to enter the structure until the directions say you can. They usually give you a timeframe that you have to be gone before you can reenter the greenhouse and many of them also make you wait 24 hours or more before you bring your plants or yourself back inside.

In any case, the important thing to remember when fumigating is to plan on it taking some time and make certain that you don’t reenter the structure until the directions say that it’s all right to do so. This is to keep you safe above everything else but also to be sure that every last bug or pest has been eliminated.

How Do You Clean a Polycarbonate Greenhouse?

Polycarbonate panes are used in a lot of greenhouses and keeping your greenhouse clean requires keeping each of the panes clean as well. Because most polycarbonate items have UV protection, you cannot scrub them or use harsh abrasives when washing them. Instead, start by washing each pane with a mild soap, such as dishwashing liquid, and water. If the water starts to get dirty, pour it out, and replace it with clean water. Do this as often as required.

As you’re washing each pane, always use an up-and-down motion going in the same direction as the flutes. In addition, never use a scrub brush or anything too stiff to clean the panes because they can easily scratch. Instead, use a sponge or a soft cloth of some type because anything else may damage the panes. You will likely have to wash, rinse, and refill your bucket more than once until the process is complete but keep repeating these steps until your polycarbonate panes look as clear as you always knew they could.

Related Posts


Popular Articles

Grower's Guides

How to get rid of moss in a greenhouse – 6 things to consider

Why is moss a problem in a greenhouse? Although moss and algae won’t kill your plants directly, if left to spread, it will begin to …

Read More →
Frosty Greenhouse
Grower's Guides

Can plants freeze in a greenhouse? 4 ways to prevent frost in the greenhouse

Can plants freeze in a greenhouse? Yes, plants can freeze in a greenhouse.  An unheated greenhouse will generally be 5 degrees warmer than the outside …

Read More →
How to grow stevia in a greenhouse
Grower's Guides

How To Grow Stevia In a Greenhouse | Ultimate Guide

Stevia is a herb grown in tropical climates for it’s ultra sweet, low calorie leaves.  The leaves can be dried and used as a sweetener …

Read More →

Recent Posts