How To Maintain & Clean Your Greenhouse

Keeping your greenhouse in top condition is easy when you know how! This section of our knowledge hub covers all aspects of greenhouse maintenance, cleaning, repairs and even gives you advice on keeping pests out of the picture. 

Cleaning Your Greenhouse

How to clean a greenhouse effectively

Ensuring that you clean your greenhouse properly is extremely important, as the dirtier your greenhouse is, the easier it is for pests and disease to spread and the harder it is for that precious sunlight to get in.

Here’s a checklist that we’d recommend you follow when you come to do your greenhouse deep clean:

Interior:

1. Remove everything from the greenhouse - you should pay particular attention to what is under all of your plants and pots. You may find that there are slugs, eggs or insects that need removing. 
2. Clean all removed pots and wipe down all sides thoroughly, work from the top-down, as this will save you time when you come to sweep all debris out of your greenhouse at the end.
3. Get a bucket of warm soapy water and begin working your way around the greenhouse, scrubbing from top to bottom. Be sure to place plenty of emphasis on scrubbing areas that are particularly covered by moss or anything of the like.
4. Once you have given the whole greenhouse a good scrub, get an old toothbrush and begin working your way into more hard to reach areas of your greenhouse and be sure to give them a good clean. 
5. Now that you have cleaned the greenhouse thoroughly, be sure to rinse well with clean water, giving the floor a good scrub and final rinse.
6. Allow the greenhouse to dry completely, this may take a day or two, don’t rush it!

1. When the greenhouse is dry, you may wish to  disinfect it with a reputable product. This will ensure all of the diseases and pests don’t come back for a good while. Take care when selecting a disinfectant, to avoid any potentially harmful chemicals, particularly if you grow organically or have any free-roaming animals.

Exterior:

1. Clear the perimeter - garden furniture, flower pots, decorations etc.
2. Remove any weeds that have made their home around the base and foundations of the structure. Pay particular attention to any sides of the greenhouse with less accessibility, such as those adjacent to a wall or fence. This will make cleaning easier and also help identify any problem spots - such as any gaps or holes where mice and other pests might gain entry.
3. Disengage the autovent openers - this will make cleaning the roof much easier as no rogue vents will start opening in the sunshine while you are working.
4. Clear out the gutters and brush away any leaves from the roof of the greenhouse with a soft-bristled brush. Now might also be a good time to take down your Rhino blinds to store them inside for the winter.
5. Once any large debris has been cleared, you can begin scrubbing the structure with soapy water. A long mop with an extendable handle is ideal for reaching all the way up the ridges.
6. We recommend going over the structure again with a fresh bucket of soapy water, to get the glass as clean as possible.
7. Once clean, you may wish to buff the glass with a soft cloth or cotton t-shirt to avoid smears.

NB: Avoid using acidic cleaning products, as this will corrode the aluminium frame.

You’ll be glad to hear that Rhino Tuff safety glass is considerably easier to clean than horticultural glass and polycarbonate, read our guide to greenhouse glazing. This is mainly down to its more robust make-up, meaning you need not worry about how much pressure you’re placing on the panes when cleaning. It’s also worth noting that there are no grooves to contend with as you might find on polycarbonate, just nice and easy flat surfaces!

How often should you clean your greenhouse?

Ideally, you should clean the entire structure of your greenhouse,at least once a year. We would recommend cleaning your greenhouse during the colder months of the year when your greenhouse is likely at its emptiest as this makes cleaning significantly easier and less time-consuming. Early spring is also a good time for a clean, before sowing commences - and if you’ve done a good clean back in the winter, you’ll have less to do come spring.

Pest & Disease Control

How to eliminate powdery mildew in greenhouses

One of the most common forms of fungal plant disease is powdery mildew. This disease is very easy to identify, as white or grey powdery spots appear on the leaf’s surface. Thankfully the disease usually looks a lot worse than it is, and it’s very rare that plants will die as a result of powdery mildew. Courgettes are a perfect example of a crop that is very prone to this issue - you can read our full guide to growing courgettes and squash here.

That said, the aesthetic appearance of your plants will be considerably worse off and growth will slow while the plant continues to fight the disease if powdery mildew does take a hold of your crops. The simplest remedies can often be the best, particularly for organic gardeners, so try combining baking soda with liquid soap to ease the symptoms. Be aware that baking soda can be corrosive to aluminium, so if you get any on your greenhouse or staging, make sure to wipe it away quickly.

There are some preventative steps you can take to minimise the chances of powdery mildew affecting your greenhouse plants as well:

• Keep plants a good distance away from each other - good air circulation is vital in preventing powdery mildew.
• Try not to over fertilise your plants; slow-release fertiliser should be preferred as it provides controlled growth.

• Minimise the shading of your plants - this shouldn’t be a problem in a greenhouse, but be sure that your plants are getting at least 6 hours of sunlight each day.

How to get rid of greenfly in greenhouses

If your greenhouse has been infiltrated by greenflies, you’re not alone. The Greenfly has earned itself a reputation as one of the more irritating garden pests as they come in droves, and as soon as one greenfly is in your greenhouse, you’ll find plenty more aren’t far behind. 

Thankfully there are plenty of ways to rid these pesky insects from your greenhouse: 

• Blast them off - simply grab a hosepipe and blast them off any affected plants. This can be a challenging technique if you’re dealing with delicate plants and crops, but shouldn’t be discounted. Be sure to check under the leaves as this is where greenfly are most likely to hide!
• Sticky traps - setting up several homemade or shop-bought sticky traps around your greenhouse is a cost-effective and simple way to get rid of greenflies. Simply grab some yellow coloured card and smear with a sticky solution (washing up liquid and petroleum jelly is fine) and hang the traps near the most affected plants. You’ll find that greenflies will flock to these traps and your greenhouse will no longer have an issue with these pests!

• Insect repellent - be careful if using this method, as some crops will be worse off if they come into contact with it. Always read into any insect repellent you’re using in a greenhouse setting, as you could find that your plants are adversely affected.

How to keep mice out of your greenhouse

It’s no secret that rodents in your greenhouse can cause a lot of damage. From eating your seedlings to gnawing at plastic pots, wood and anything else that they can get their paws on, they’re trouble!

There are several simple steps you can take to keep mice out of your greenhouse, but you really must be vigilant and keep an eye out for signs of rodents in your greenhouse and garden at all times. Firstly, if you do have any open areas of your greenhouse, whether that be a broken pane of glass or a faulty louvre, be sure to get them blocked off. If you deny access to mice at the source, then you shouldn’t have any issues with them, it’s as simple as that! 

If you don’t have any easy access points for mice to enter, then we’d recommend cleaning up your greenhouse so there’s nowhere for them to hide. Overgrown grass and weeds housed in your greenhouse are great places for rodents to hide away, so be sure to keep everything neat and tidy. Also, it goes without saying, but don’t leave any pet food in close proximity to your greenhouse as this will attract mice and other rodents. 

How to get rid of fungus gnats in greenhouses

Whilst fungus gnats won’t actively eat your crops, they’re a general nuisance in your greenhouse and are known for transmitting fungal pathogens such as Botrytis. You can be forgiven for wanting to rid your greenhouse of fungus gnats

Dealing with these pests is very similar to ridding your greenhouse of mice, as you’ll need to maintain a weed-free environment in your greenhouse and keep it generally clean. Fungus gnats are attracted to dead and decaying plant materials so it’s important to take the time to properly clean your greenhouse regularly and keep an eye on overgrowing and decaying plants. Along with this, try not to overwater plants too much as fungus gnats are drawn to abundant moisture.

If you keep a compost bin in the greenhouse, you may also want to consider relocating it if you have a continual problem with fungus gnats.

If you’re struggling to get rid of the pests by using these prevention tips, then you can use biological control methods such as nematodes. We prefer using nematodes as it is extremely effective against fungus gnats and is safe for your plants.

Preserving Your Greenhouse 

High winds & storms

In the event of high winds and storms, it’s important to prepare your greenhouse as soon as possible, ideally, a couple of days before the weather is due to hit. The most important thing is to secure the structure and make your greenhouse as airtight as possible. If wind manages to get into the greenhouse, it can cause a multitude of issues; so be sure to secure everything in your greenhouse.

Read our blog for more information on preparing your greenhouse for high winds and storms.

Keeping your greenhouse insulated in the winter

It’s important to ensure that your greenhouse is kept as warm as possible all year round, especially if you plan on housing plants over the winter months. Bubble wrapping your greenhouse is a go-to for many owners and does help keep a substantial amount of heat within the greenhouse.

The purpose of adding bubble wrap is to provide a layer of insulation. But it is best not to go for the average packaging variety, and instead go for horticultural bubble wrap.

This is best done after the annual clean. Make sure all the glazing is clean, nooks and crannies are clear and a general purge of dirt, pests and disease has been done. Give the greenhouse a chance to air and dry after cleaning. It is important to reduce the moisture inside as once the greenhouse is wrapped, you will likely lose easy access to your louvres and vents.

You should also be aware that because bubble wrapping the greenhouse makes air circulation more difficult, it’s important to leave the doors open regularly to prevent build up of all the things we’ve just been telling you how to keep out!

For a complete guide to bubble-wrapping the greenhouse, click here.

Or here for other ways to keep the greenhouse warm in winter.

Repairing Your Greenhouse

What to do if the glass breaks?

There’s nothing more frustrating than when your greenhouse glass breaks, it’s a major inconvenience and a safety concern for anyone using your garden space. You’ll find that the way you need to approach the breakage is different based on the type of greenhouse glazing you have installed.

Horticultural glass needs to be delicately disposed of due to its sharp edges, so take care when handling it. You’ll need to remove all of the clips that hold the glass in and carefully remove the pane, being sure to cover the hole left in your greenhouse until a new pane can be delivered. 

In the unlikely event of your Rhino Tuff safety glass breaking, you’ll find that the glass breaks into thousands of tiny pieces. This is a much safer break than horticultural glass, as there are no large sharp points left in the smashed glass. Simply remove the glass, sweep up and dispose of it. Once safely disposed of, be sure to cover the exposed area, and contact our friendly team who will be happy to help you get a new pane delivered as soon as possible.

You can find out more about Rhino Tuff 4mm toughened safety glass over on our glazing section of the knowledge hub. 

All of our Rhino Greenhouses come with a 25-year guarantee, which tells you just how confident we are that they will stand the test of time! If anything does happen to your greenhouse, be sure to contact us and we’d be happy to see how we can help.