I have recently got and am using a gas greenhouse heater (propane) ..Thermostat controlled range on a dial from just above freezing up to about 66 degrees. This seems to me to be the best way to go if You haven't got electric to your green house...Have been down the parafin road and the cost as well as maintaining wick etc put me off ..lost quite a few plants to parafin last year ...will inform you as to how successful the gas is, Up to yet it seems fine ...Cheers ..Jim
Didn't know such things existed Jim. What about cost? And smell? I've never used paraffin heaters cos I can't stand the smell.