MIKE I’ANSON, of Helmsley Walled Garden, makes it crystal clear that greenhouse maintenance should be top of our February essential to-do list and not be viewed as a pane in the glass.

FEBRUARY starts the growing season and as we have about 800sq metres of glasshouses here at Helmsley Walled Garden, now is the time to clean and sterilise as best we can. You can’t eliminate every pest or disease lurking in the plants, composts or framework, but you can seriously reduce their population levels.

We discard all glasshouse plants held over from last season, but if you want to keep any plants, take them outside on a frost-free day and remove all the compost, wash the roots off, and re-pot with new compost. Check the whole plant thoroughly for any pests and remove by hand or with a toothbrush.

Keep plants in a frost-free garage or potting shed and clean your glasshouse by washing down all the glass and woodwork using common household detergent. Remove and clean all plant pots and remove staining between overlapping glass panes with a gentle spray from a power washer or a hose pipe. If you have a glasshouse soil bed, consider removing the soil at least every three years because pests and disease will build up here; new soil can come from the vegetable patch.

We sterilise the inside of our glasshouses by lighting sulphur candles to burn overnight. To do the same at home, check no pets are anywhere inside the greenhouse, ensure all windows and doors are closed, any holes or vents are blocked and the candles lit. Follow the instructions and do not inhale the vapours.

The following morning, ventilate the greenhouse and remove the spent candles. Your greenhouse is now ready for the coming season. We use new plants, compost and cleaned plant pots together with the newly-sterilised glasshouse: pests and disease are now at such a low level that hardly any controls and certainly no chemical control is needed throughout the year.

This year we’ll be working on the backlog of repairs of our glasshouses. Although renovated in 2007/8, they are now starting to show signs of wet rot in a number of the roof slats.

Wooden glasshouses need continuous maintenance: our Victorian and Edwardian gardening forefathers would have called upon the estate joiners to do any woodwork repairs. The gardeners’ maintenance would have consisted of placing planks of wood across the main stays of the roof, often with just a nail to secure and sending a small boy up to paint the frames with lead paint.

Today, the Working at Heights Regulations forbids putting a workman never mind a small boy on the roof of a glasshouse.

We can, with training, obtain a licence to use lead paint; modern water-based paints only last 18 months on a glasshouse, and we will have to take the glass out to paint the frames.

But for the time being if you know of a retired joiner who would like to volunteer to help set up our own joiners’ workshop, help train others and set a work schedule I would be very much obliged.