Some gardeners believe they can be lazy in winter, but this is the best time to set up a greenhouse for the spring and coming year.
Start by planning for a whole day of decluttering and cleaning. All manner of plant pots, dry plant stalks and tools seem to accumulate in the greenhouse once the main growing season is over. Clear out all of the unwanted stuff, and give the greenhouse a good clean inside and outside.
This is the point at which you can decide what you would like to grow over the coming year, as well as how to organise shelves, benches and tools and how to heat and ventilate the greenhouse.
Plants suffer from fungal infections when there is insufficient ventilation. So you need to ensure that there are sufficient openings on the roof and walls. Two air vents in the roof and one vent on two of the greenhouse’s sides is the best policy.
Hot sun during the summer can also shrivel plants in a greenhouse. You can combat this by installing some blinds inside it. If this is too expensive and takes space away from pots and plants, buy a shade netting to throw over the greenhouse during the hot sunshine.
Install electricity, and a thermostat, to provide a light source and some heating. This will help you to work in the greenhouse during the evening, as well as propagate plants for longer. But this has to be done by a qualified electrician.
If an electrical connection is too inconvenient or too expensive, a paraffin heater will provide enough heat to keep the greenhouse’s temperature above four degrees Celsius in winter. Try to use one with maximum and minimum settings, but also make sure that you check it twice daily when it is running.
Remember that greenhouse plants are very thirsty and will use much more water than those growing outdoors. They also like rainwater rather than the stuff from a tap. A couple of down pipes connected to a water butt from gutters fixed at the top of the greenhouse walls will solve this problem and probably store up sufficient rainwater for most plant needs.
It’s also a good idea to keep an extra bucket of water inside the greenhouse, where it will warm up to the ambient temperature. Plants do not like freezing water. On hot days the bucket of water will also keep the interior sufficiently humid.
You can grow plants in pots, in soil on benches and shelves along the length of the greenhouse or in grow bags on benches. It’s probably a good idea to invest in all three and decide where to organise them inside the greenhouse. The only exception to this rule is if you intend just to grow tomatoes, peppers and cucumbers. These plants will need the entire height of the green house to grow in.
Keep the area around the immediate exterior of the greenhouse clear and preferably gravelled or paved. This will allow any water from inside to soak away and also help with maintenance.