That's really what I was trying to find out. I have three greenhouse books of various vintages and I have searched the RHS but the only place that sulphur smoking seems to be advised is on the sulphur candle tin! I guess the idea is gas will penetrate all the nooks and crannies better than a liquid will. I filled the sprayer and covered the inside getting into all the little nooks and crannys then left it shut up for two days.

Seriously, it does sound a lot of fiddly (and dangerous?) work just to avoid paying a bit more than a proper sulphur candle which always works at the first lighting and without having to be messed about.

I'm interested in any answers too as when I went to get the Jeyes in the GC the shelves were full of organic natural disinfectants which I bought. Sow your seeds, plant your plants. What's the difference? A couple of weeks or more when answering possible queries!

The alternatives seem to be all permethrin based which would kill all crawling/flying insects in the greenhouse but not eggs or fungi - at least as far as I know. Since there isn't much flying or crawling around in it in February/early March it would seem to be a bit pointless. Although beeswax sulfur candles are better for the environment than pesticide foggers, they're just as harmful to your lungs and mucous membranes, so gloves, goggles and respirators are mandatory. I have often bought a Sulphur Candle but they seem expensive. Mind you the price for the commonest one, 300g Deadfast, seems to vary from 3.99 at selections.com to 7.95 at TwoWests. Do you know of a cheap supplier? Alternatively can you still buy Flowers of Sulphur (where from?) and burn that somehow? I have found a diy blend of beeswax and Sulphur to make your own. Are there other smokes that are equally effective and economical?I certainly cant do this at the moment , since although Cornwall is not as cold as other parts of the country ,it is still too cold to take out all my plants and stand them outside while I clean it . I have a brand new greenhouse that only went up in November should I do anything e.g. Sulphur Candles etc before I start using it? Wear a respirator and lab safety goggles when working with flowers of sulfur and when lighting the candle.