Like many gardeners around the country, the Sunday Gardener's greenhouse is unheated and mostly I've managed fine. I am just about to start the new season sowing, starting with Sweet peas and moving on to various veggies and annuals.
I get germination off to a good start by using a heated mat, and then grow on for short while on warm window sill, or in the conservatory, gradually moving out and hardening off in the unheated greenhouse later in year around March/April.
Until recently I hadn’t seen the need for any heat in a greenhouse, but we have had such bad summers I am now having a re think.
Heat in greenhouse would help to bring on the bedding plants so bigger plants would be ready for planting out come May/June, and maybe later more flowers, even if the summer is poor. Last year I grew squash, but the crop was very poor even grown in the greenhouse. Obviously much depends whereabouts in the country you garden, and the aspect of your garden, but heat would prolong the growing season and produce better growing conditions with less temperature variations.
Whilst mulling this over what is the experience of other gardeners?