Greenhouses in winter

Before setting up your winter greenhouse, disinfect all growing surfaces and power-wash the roof panels and outside walls to remove algae, mould and stains, you also need to treat cedar or redwood frames with teak oil or some other preservative; and lubricate vent openings and door hinges as well as checking your heating system. You may want to install a layer of bubble wrap on inside walls or stack insulating bales of straw or hay along exposed walls in country areas. Caulk or fill draughty air spaces. Seal openings around doors and vents with foam tape. Use aerosol cans of foam for plugging holes around electrical boxes or along floors and foundations. Drain water lines unless you plan to heat your greenhouse through winter

Now you need to set up a weekly check that the plants being over wintered are healthy. Pick off discoloured leaves and dead flowers, which encourage disease and water plants sparingly ensuring there is good circulation around the foliage, to prevent fungal diseases.

Winter tasks

Bulbs in bowls – plant up bowls of spring-flowering bulbs, including crocuses, narcissi, dwarf irises and tulips. Then place them in a cool area of the greenhouse to develop.

Lettuces – plan to have a continuous supply of crops for harvesting through the autumn months and into winter by planting hardy lettuce varieties such as 'Winter Density'.

Citrus fruits – if you have a heated greenhouse you might want to try forcing citrus fruits for Christmas, or peaches perhaps. This requires close concentration on heat and light, turning pots daily and ensuring good pollination of fruit in the summer months.