The Cottage Smallholder

Our polytunnel used to be 60 ft long but after a careless lorry driver damaged one end it's now shorter!  You will find that a greenhouse holds heat more evenly than a polytunnel.  Temperatures are more extreme in the tunnel.  For really early seedlings we have a cheap 4 tier mini greenhouse inside the tunnel which we zip up at night.  You also need to factor in that the polythene cover needs replacing after a few years.  There are various grades, some of which have better UV tolerance.  We have to dig the polythene out of a trench each time we recover the hoops so once the current one has run it's course we will not replace it.  You also need a very still day and lots of help to cover the hoops.  Good ventilation (as with a greenhouse) is very important.  Take note of the prevailing wind in your area and position your greenhouse/tunnel accordingly.  One of our first tunnels took off in a gale - not something we would wish to repeat.   Hope that helps.

Hi Bonnie. One of the tunnels we had was positioned N - S and that's the one that blew away!  It depends on how exposed your site is.  We are on the spine of Cornwall and are susceptible to gales/high winds from both coasts.  Our prevailing wind is normally from the SW. Once a high wind gets inside a tunnel it will find any weakness.  On this particular occasion the wind ripped the doors open and there was nothing we could do.  I guess in landlocked Wiltshire you will be less vulnerable.  Good luck!