Hartley Magazine

All the latest news, hints, tips and advice from our experts

Cleaning the Greenhouse

When is a good time to clean the greenhouse? Many gardeners recommend early spring, just before seed sowing when over-wintering pests can be got rid of, but I’ve chosen my first major clear-out in October.

I could have kept my tomato plants going for much longer, but I decided to boot them out because it was getting so hard to move about in the greenhouse. In a frenzy of clearing I harvested all my chillies, the small Thai aubergines and the jungle of tomatoes.

My reasoning for an autumn clean-out is that in January I’ll be starting off my peppers, so I don’t want to disturb them once I’ve got them going. Then in early spring, just to be thorough, I’ll give the greenhouse an inspection before the big seed sowing season to see if it needs a spring clean.

I could be letting myself in for problems later on, but gardening is about trial and error, and you learn as much from mistakes as from successes.

So, how do you clean a greenhouse? When I first got my allotment, I can remember some of the older plotholders used nicotine to fumigate the greenhouse. The EU has since cracked down on the use of many noxious substances.
Remember to clean the glass outside to let the maximum amount of light in during winter. Clear the gutters too.
Wash down all the staging, paying special attention in corners and underneath.
Cleaning Products for the Greenhouse: here are some of the most common substances used.


An organic, citrus based cleaner which is mild but effective.


Use white vinegar diluted around 1:8 parts.

Jeyes Fluid

Dilute to clean surfaces. It can also be used to sterilise soil, though it will kill off good bacteria too. Fairly pungent, so ensure good ventilation.


Armillatox is a soap useful for cleaning trays, staging and other surfaces in the greenhouse.
Greenhouse Hardware


Give them a good scrub, inside and out with a pot-brush and scourer. Leave them outside to dry naturally, when fully dry store in the shed. Wrap them in plastic or bin bags if you are going to leave them outside.

Capillary Matting:

The received wisdom is that this should be replaced every year as harmful bacteria can easily kill off your precious seedlings. It’s not terribly expensive so replace every couple of years if you are feeling frugal.
Windows: Use a plastic plant label to get to the algae under glass and in corners. Disconnect your water butt before cleaning the top panes with mild, soapy water.

Water Butt:

Empty these once a year and hose them down inside. Check them regularly and make sure they are free of leaves or snails.


If you really want to clean the greenhouse properly, remove all the gravel and wash it through with a proprietary cleaner. In practice this is quite a job. You can use a watering can to administer Jeyes Fluid or another cleaner. It won’t be quite as effective as total removal, but should help if the above is unfeasible.

Border Soil

Use Jeyes Fluid to sterilise or replace altogether every year. Many gardeners now use growbags in the greenhouse.