If, like me, your main growing seasons are spring and summer, you should start getting your greenhouse in order towards the end of winter.
If you already attended to this task in the fall and are housing seedlings in there over winter, I would still highly recommend going in and giving your greenhouse windows a wipe down, and removing any build up of dirt and grime which might be reducing the amount of light getting to your plants.
'Cleaning your greenhouse is a crucial task since it's an opportunity to tackle some common woes like mold, mildew, pests, and algae,' says Veronica Sparks, of Homesteading Suburbia.
So if the weather permits, set aside a few hours this weekend and settle into what I guarantee will be an extremely satisfying and rewarding task.
How to clean a greenhouse to help your seedlings flourish
If you're a fair-weather gardener, this may be the first time you really get stuck into an outdoor task in 2024. Personally, I can't wait to get out into the backyard, and feel like I'm getting some control back after the winter.
I find that a tidy greenhouse or potting shed is a fantastic motivator to getting my hands on some new growing projects, and gives me a jump start on the gardening year ahead.
Because cleaning a large structure, DIY greenhouse or cold frame properly is such an important task, I approached expert in greenhouse care Gayle Dawson-Williams of Wisconsin Greenhouse Company for her methodical approach on how to clean a greenhouse.
You want to do it in such a way that turns it into a neater working environment, as well as a healthy one, where pests and disease won't fester.
1. Empty your greenhouse and remove debris
'Begin by removing all plants from within the greenhouse,' says Gayle. 'I work from the top down, including exterior and interior. A soft brush will loosen any debris from interior and exterior framing, glazing, and benches.'
'I then sweep out or use a shop-vac to remove any loose material in the interior and sweep debris from areas where any gutters will drain in the exterior,' she says.
2. Clear out the gutters
Another greenhouse tip is to clear dead leaves and other debris from your gutters. Clearing gutters is particularly important if you've decided to attach a rain barrel when planning a greenhouse.
'Wipe all gutters and downspouts with a mild enzyme detergent or diluted hydrogen peroxide. Rinse well with water,' says Gayle.
A diluted hydrogen peroxide mix is safe for plants and vegetables to grow in a greenhouse, and surfaces, try this 128 oz. 12% Hydrogen Peroxide All Purpose Cleaner at The Home Depot.
But if you’ve noticed algae, mold growth or fungi, opt for an enzyme-based cleaning solution or a specialty product for greenhouses with either quaternary ammonium compounds or hydrogen dioxide.
3. Clean down all your glazing
Dirty windows can really affect how well your greenhouse functions. 'They reduce sunlight penetration, hinder plant growth, and create a less favorable environment for sowing flower seeds indoors. Regular cleaning helps maintain optimal conditions,' says Veronica Sparks.
'Check for mold and dirt gathered in framing profiles and glazing seals, and remove with a stiff implement if you can, then disinfect.'
'Then using a soft brush or sponge, scrub the glass down inside and out. 'Use a squeegee to keep glass crystal-clear as you rinse,' says Gayle.
Alternatively Veronica suggests you wipe your glazing dry with a lint-free cloth for a streak-free finish.
4. Sanitize benches and pots
'Rinse well on both interior and exterior, then clean your growing benches. Clean flower pots and any containers which will be reused. They should be scrubbed well with a stiff brush and your chosen cleaning agent, then rinsed and set in the sun to dry,' says Gayle.
'If you use irrigation tubing inside of your greenhouse, rinse it and soak in hydrogen peroxide mix, and rinse again, taking care that all joints and valves are wiped clean,' she says.
Cleaning a greenhouse is a good opportunity to get rid of any broken pots and seed trays. You may also want to take this chance to organize the space in order to optimize how you use it.
Also remember to check for any mold growing on seed trays.
FAQs
How do you sanitize a greenhouse?
A home-made dilution of hydrogen peroxide and water is Gayle Dawson-Williams, of Wisconsin Greenhouse Company's, favorite sanitizing solution for greenhouses.
But there are a number of commercially available greenhouse disinfectants for pathogen and algae control. 'Quaternary ammonium compounds, hydrogen dioxide, hydrogen peroxide blends, and algaecides for greenhouse use are commercially available, and chlorine bleach can be an option if very well rinsed,' says Gayle.
'Alcohol can be used to disinfect propagation tools but is generally not used for greenhouses,' she says.
Can I power wash my greenhouse?
Power washing may be used if your greenhouse structure and materials can stand up to high pressure water jets but will not disinfect or help keep further bacterial growth at bay,' says Gayle Dawson-Williams, of Wisconsin Greenhouse Company.
'Pathogens may still be an issue if power-washing is the only step you take in greenhouse cleanliness,' she says.
Can I use vinegar to clean greenhouse?
According to Gayle Dawson-Williams, of Wisconsin Greenhouse Company, vinegar can be used on greenhouse glass after disinfecting, in order to achieve a streak-free shine.
However she explains it's not recommended for surface cleaning as it does not effectively eradicate pathogens known to affect greenhouse environments.
Can I use bleach to clean my greenhouse?
'You can use bleach to clean your greenhouse, but it should be used sparingly and with caution,' advises Veronica Sparks, of Homesteading Suburbia.
'For example, if you have a bad mold problem, bleach may be the best way to tackle it quickly before it kills any seedlings you have growing.'
'Dilute bleach with water (approximately 1 part bleach to 9 parts water) and wear protective gear when you're cleaning. Ensure thorough rinsing to prevent residue and potential harm to plants,' she says.
If you're in the zone for cleaning and organizing. Why not check out our shed organizing ideas and get all your garden structures in order.
