You’ve filled it with plants, fruits, seeds and vegetables and are enjoying your extended growing season. But if you want to ensure your greenhouse lasts in tip-top condition for many years to come, you’ll need to care for it every now and then.

Cleaning Outside of the greenhouse

• Remove any debris from the area around your greenhouse and sweep away any fallen leaves or built up dirt.
• Wash the outside with warm water and a sponge. To clean the roof of your greenhouse, use a mop or a sponge with an arm which can be extended. If you don’t have one, attach your sponge to a broom handle or bamboo cane.
• Clean beneath the window panel joints with a hose to remove any hidden dirt.
• Look for any broken or cracked glass panes, as well as for any signs of damage to the frame, and repair any damage found to ensure that your greenhouse is providing the best possible environment for its plant inhabitants.
• If you have a wooden framed greenhouse, inspect the frame and apply a wood preservative to any areas which need to be touched up. This will help keep the frame protected from rot for longer.

Cleaning Inside the greenhouse

Now that the outside is all sparkly and clean, it is time to step into your greenhouse. This part is a little more involved, so have a cup of tea or coffee and a small break before starting.

• If you have any electrics in your greenhouse, switch them all off and disconnect them from the mains, if possible.
• Organize all of the empty plant pots and grow bags into ones you will keep and ones you will throw away.
• Remove the equipment you will keep, all plants (wherever possible), and all shelving units. If it is winter, move any sensitive plants to a shed, a conservatory, or someplace sheltered.
• Dispose of the pots and bags you don’t need anymore.
• Use a broom to brush the interior walls and ceiling to remove dirt and cobwebs.
• Follow this by sweeping the floor of your greenhouse to remove fallen leaves, dirt, spilt soil and any other debris that has accumulated.
• Clean every surface on the inside of your greenhouse with warm water, a disinfectant, such as a hydrogen peroxide, and a sponge.
• Inspect all windows and vents to ensure they work correctly. If they are difficult to open, put some oil or commercial lubricant on the joints and hinges so that you can keep your greenhouse well ventilated.
• Wash all shelving units with warm water and disinfectant before moving them back inside.
• Disinfect all empty plant pots and containers.

Humidity Maintenance

The humidity level in greenhouses is often much higher than that on the outside, which is beneficial to many plants. However, if the humidity level is neglected, it can cause the air inside to become either too humid or too dry. To maintain a decent level of humidity and keep plants healthy, check out the following tips.

If you feel that the humidity is too low, place a tray or a small bucket of water on the floor of your greenhouse during the day. The evaporating water will help raise the humidity level.
During hot summer days, it is best to keep the humidity in your greenhouse to a minimum. Open the vents and windows during the day to make sure that there is a constant flow of incoming cold air and expelled warm air.
Watering plants with cold water during the summer can cause the roots to enter a state of shock, which will reduce their effectiveness at absorbing moisture and nutrients. Avoid this by keeping a full watering can in your greenhouse throughout the summer. This way, the water will be kept at a similar temperature as its surroundings.
You can collect a lot of water from the roof of your greenhouse. Install some simple gutters leading to a water barrel for a free, natural supply of water for your plants.
Any hoses used for watering should be checked for cracks, holes, or blockages routinely. Remove any attachments and run water through the hose at its maximum capacity. This will dislodge any blockages and show you if there are any holes in the hose.

Pest control tips

The bane of every gardener is plant-destroying pests. They can strike at almost any part of your garden and will do an extreme amount of damage if left unchecked. Be extra prepared by checking out our garden pest control articles here:

As greenhouses are somewhat isolated from the rest of the garden, it is much more difficult for pests to establish a foothold on the plants from within. But that doesn’t mean that this is impossible since garden pests are persistent in their quest to eat your plants. There are, however, a few steps you can take to keep your greenhouse a pest-free area.

Control what enters your greenhouse. You have the final say over which plants have the privilege of living in your greenhouse. Carefully inspect every plant for signs of pest activity before welcoming it into the greenhouse club.
The enemy of my enemy is my friend. Some plucky pests will inevitably slip past your defenses and begin to establish a home for themselves. Resist the urge to reach for the pesticide. Instead, capture the pests’ natural predator and release it inside your greenhouse. For example, if you find aphids sucking the vitality out of your plants, catch some ladybirds from your garden and watch as they decimate the aphid population.
Keep your greenhouse clean. Cleaning the inside of your greenhouse, as well as all work surfaces regularly with warm water and disinfectant, will help to keep pests at bay. As a bonus, you will also have a pleasant gardening environment to look at.
Stay vigilant. Check your plants for signs of pest activity every day. Things to look for include holes on the leaves and plants withering unexpectedly. As soon as you discover an infested plant, remove and dispose of it immediately, otherwise, the pests will spread to other plants in your greenhouse or garden.