Greenhouses must be regularly cleaned and sanitized to protect plants against diseases, pathogens, insects and weeds. Preventative cleaning and sanitation measures become even more crucial during winter when less plants occupy the greenhouse.
As part of your gardening year cleanup routine, begin by clearing away any large debris or waste that has accumulated, then sanitize all glass surfaces inside and out.
1. Remove Debris
Over time, dead plant material, moss, algae, dirt and pests will accumulate in your greenhouse. A thorough greenhouse cleaning will eliminate this build-up to help ensure healthy plant growth in an ideal growing environment.
At first, use a vacuum cleaner or broom to quickly and thoroughly clear away any dust or debris accumulating in the greenhouse, replacing any old diseased soil as needed. Ideally, do this when there is sufficient ventilation in the room and no plants present to make clean up easier.
Next, eliminate any weeds that have taken hold in your greenhouse to help ensure its soil remains nutrient rich and avoid them competing with your crops for resources.
Consider installing a weed barrier around the outside of your greenhouse to control weed growth and make upkeep easier. This will make maintaining a beautiful greenhouse easier!
Now that the debris has been cleared away, it is time to start cleaning the actual structure of the greenhouse. Begin by sweeping its roof, gutters and sides using either a broom, vacuum cleaner, hose with jet wash attachment or any combination thereof – taking great care not to damage either roof or glazing as this may damage it further. In order to be safe, test any cleaning products on an inconspicuous area first to make sure that none do any lasting damage to glass or plastic panels.
Once your greenhouse frame has been thoroughly scrubbed, move on to cleaning its windows and other glass structures. A solution of Citrox in warm water will help eliminate any unwanted organisms that might be lurking within its confines; be sure to pay special attention to nooks and crannies where pests and disease might hide.
if there is an abundance of moss on your greenhouse roof or sides, using either a ladder, scrub brush and scraper or wearing a mask, to access these areas may be necessary to rid yourself of it. Moss contains insects as well as diseases which should not be neglected when doing this work.
2. Clean the Glass
Routine greenhouse glazing cleanings should be performed regularly to maintain light transmission. This helps avoid dirt build-up and spore formation that may impair air circulation and restrict plant growth. An optimal time for this activity would be early spring or autumn when plants have yet to bloom and temperatures are still relatively mild.
Begin by emptying out your greenhouse of all pots and staging, taking all tools with you outside and unplugging any machines such as heaters which may still be connected. This will give you ample working space as well as simplify the cleaning process.
Once all pots and staging have been removed, sweep the floor to clear away dirt or cobwebs, while opening your greenhouse door will allow airflow throughout. When dealing with polycarbonate greenhouses it is especially important to pay close attention to their glazing material as this type of greenhouse tends to collect scratches more easily requiring you to scrub down with vinegar solution before cleaning with warm water rinsed with clean cloths.
Step two is to thoroughly wash down both the frame and glazing with warm soapy water or disinfectant (we prefer Citrox solution in our greenhouse), paying particular attention to low areas where dirt accumulates or hard to reach corners – both can significantly decrease sunlight reaching into your greenhouse. A hose attachment and cleaning sponge will help reach tight areas; alternatively a telescopic cleaning brush attached to a hose provides access to high places – but use with care not to damage it!
Be sure to thoroughly clean all structural parts of the greenhouse, such as its gutters which may become blocked with moss and algae growth, before disinfecting any tools used inside such as gardening gloves or trowels used within. Chlorine bleach, hydrogen peroxide or ethanol solutions can all provide effective disinfectants; just be careful using chlorine bleach on metal surfaces as this can lead to corrosion issues.
3. Deep Clean the Walls
Once you have removed all fallen leaves and scraped away thick moss or debris from the greenhouse gutters, it is time for a deep clean of your greenhouse. This involves spraying both its interior and exterior with hot soapy water mixed with some horticultural disinfectant (preferably Vital Oxide) in order to sanitise thoroughly the area.
Empty the greenhouse, and move any plants that need it into another structure for shelter from the cold while you clean. Start at the top and work your way down, sweeping and brushing walls and the structural frame as you move down towards glass panes; especially between panes if possible; pay special attention to crevices like window ledges or overhead pipes, where bacteria and disease-causing microbes may hide out, such as window ledges.
Use a sponge, soft scrubbing brush or car wash mop (with telescopic poles) for this task. Or alternatively use chemical solutions like rubbing alcohol or bleach-diluted with water; just be careful that any chemical solutions don’t soak through and come into contact with plant roots in any areas where you might use this approach.
Once your greenhouse has been thoroughly washed with hot, soapy water and squeegeeed, the next step should be sanitizing its plants. You have two options for doing this – either individually wiping down pots with damp cloths or sponges or taking all pots out and giving the entire frame, shelves, workbenches and furniture an intense scour using mild detergent such as washing-up liquid.
At this point, it’s also wise to replace old soil with fresh compost or soil that has been treated with fungicide such as copper sulphate or Dithane. Once that has been accomplished, reassembling all your equipment may take about half the time previously expected; before doing so though, consider installing a weed barrier as this will stop further growth and make cleaning quicker and simpler in future. Additionally, take this time to check for any rotted equipment as well as lubricate all hinges and clips on roof and doors as needed!
4. Clean the Floor
Clean greenhouses in cold conditions do more than look nice; they help prevent disease and pest infestation. Therefore, maintaining a daily or weekly cleaning schedule is vital if you want to stay disease free and pest-free. Eliminating debris such as leaves by regularly sweeping, raking and clearing the area are all things to consider in keeping a greenhouse tidy and minimise big clean-up sessions.
Once debris is cleared away, take the time to wipe down all glass panes using a solution of warm soapy water. Starting at the top and moving your way down towards corners and crevices where dirt tends to accumulate. After wiping down all the glass surfaces, take time out to wipe down your greenhouse’s structure as well, taking extra care to reach all corners and surfaces; you may require using ladders or long-handled brushes if reaching higher places is proving challenging; it will definitely pay dividends!
Once again, begin cleaning walls. If you are working inside a Polycarbonate greenhouse, removing plants to another sheltered location might give you better chances at reaching those hard-to-reach places and scrubbng down, which is important since bacteria may hide among window ledges or between glasses.
Once your walls have been scrubbed clean, use a clean hose to rinse them off completely before drying them completely – this may take one or more days in some instances – and treating with an effective disinfectant spray.
As it can contain chemicals that are phytotoxic to plants, it’s wise to choose one without any quaternary ammonium compounds or other potentially toxic ingredients. A 10 percent solution of household bleach works fine but beware that its strength diminishes rapidly – half will have gone in just two hours and this could prove dangerous for certain types of plant life.
Once all walls have been thoroughly scrubbed, give your greenhouse one last thorough rinse with a clean hose before allowing it to air dry for several days before adding your plants.