Hot tips to save on greenhouse costs

Is it worth installing a greenhouse heater? – Lester, London DAVID: Greenhouse heaters can be great but cost money to run – and you have to be careful with humidity as they can dry the air out. If you use a gas heater, you also need to ventilate your greenhouse.

If your plants are not too vulnerable you may be able to get away with insulating your greenhouse using bubble wrap and cardboard. That can help to bring the internal temperature up by a good three degrees.