Prepare the greenhouse for winter use

If are fortunate to have a greenhouse or even a coldframe, lean-to or conservatory, it’s time to prepare this space for use over winter or for the growing season next year. A safe place for less hardy plants, greenhouses also give us the ability to extend cropping of veg and fruit thanks to the extra heat and better light transmission. They’re also ideal for storing plants over the winter, but they need a bit of preparation first. Here are a few important steps to keeping your greenhouse or cold frame in good order.

Cleaning

Cleaning inside and out for winter is very important – if you have the time to do just one thing in your greenhouse/cold frame, clean it. Check guttering and clean, wash all windows inside and out to make the most of light levels. Weed, scrub pots, workstations, staging, and trays. This will all help keep diseases down.

Insulating

Insulate your greenhouse to help retain more heat through the colder months.
Measure all sides of the greenhouse and the roof. Use pins, clothes pegs or specially designed clips (from garden centres) to secure in place. When buying bubble wrap make sure it is designed for greenhouses. It will have larger bubbles, be UV-Stablised and last longer.

Pest and diseases

Many pests and fungal diseases can survive through winter in a greenhouse. Spidermite will overwinter, scale will continue to spread and whitefly can cause an infestation. Slugs also enjoy greenhouses and their warm, damp conditions during the colder weather. Check daily and treat if needed. Cleaning will keep pests down. Continue using sticky traps to catch flying insects. Prevention is better than cure.

Soil care

If you have a soil border in your greenhouse, now is the time to dig it over. If you have been growing tomatoes either replace the soil or rest it from growing them next year to make sure viruses do not build up. Feed the soil with well rotted manure or compost. Water through winter so it does not dry out. Turn over to improve soil structure.

Plant care

* Move plants into the centre of the greenhouse to reduce risk of frost damage – greenhouses are colder around the sides. If the plant is touching the glass it may get frost damage.

* Check plants daily for dryness and water when necessary, water if possible during the day when light is at its best.

* Store compost inside in case you need to use it, so it is not frozen, easy to use and the structure is not ruined.