Before I start populating my greenhouse with plants, I always hose down the glass on both sides and scrub it with a broom. This helps to clean off any dirt, bacteria and mould spores.

One thing that I have found to be a very worthwhile investment every year is a greenhouse Sulphur Candle. This is basically a tin of sulphur pellets and a paper “wick”. You light the wick, the sulphur melts and burns and produces sulphur dioxide, a gas well known to kill all manner of pests. Sulphur Dioxide is used in various industries for sterilising equipment, so why not use the same thing in your greenhouse?

It not only kills insects, but also fungal spores. This is very important in the warm and often humid conditions in a greenhouse.

In the UK, a sulphur candle costs about £4.95 and will kill all bugs inside the average garden greenhouse. My experience has been that in years when I’ve used a sulphur candle, my plants do much better than in years when I don’t.

When To Use It
Use the sulphur candle right at the beginning of the season, before you put in any plants or sow any seeds. If you have already started, you will need to take out the pots and seed trays before using the candle.

How To Use It
Place the opened tin on a brick (or the floor if you have stone or concrete flooring). Close any vents and be ready to close the door. Light the wick, ensure it is burning and then get out and shut the door. The sulphur grains will melt and burn with a blue flame, and produce smoke which will eventually fill the greenhouse.

Leave the greenhouse undisturbed for about 12 hours and then open the door and vents to let fresh air in and to evacuate any residual fumes.

After about an hour, you can put back any plants that you had removed.

This really works – it’s 5 pounds well spent. I very rarely lose any plants to fungus and I have never used any other fungicides on my plants.

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