Polytunnels and frost

[Angry Janice]

I have just bought a green pollytunnel, about 15 foot by eight foot and have it crammed full of every conceivable plant in pots. If a sudden frost comes, as other allotment folk keep telling me, will the plants survive or do I need to heat it in emergency situations?

And if so, what is the absolute cheapest method of heating it?
Thanks in advance.
Janice

[King Carrot]

Solar heating of water in containers is probably the cheapest, and if you're on an allotment anything else might be difficult to manage unless your plot is at the bottom of your garden.

Fill up bottles, drums, buckets and anything else which holds water, the bigger the better and position around the greenhouse nearest the tenderest stuff. The water will warm up in the greenhouse during the day and release heat as the temperature drops at night, might be enough to keep things from damage and it's free heat. Stones and concrete blocks are another alternative, though personally I find water is better as it also warms from the air temperature in the GH as well as any sunshine.

[Two_Sheds]

What plants do you have in there? The only ones you need worry about are the tender ones, things like tomatoes, chillies, French and runner beans

Your last frost date is late April, so you're nearly out of the woods. However, those tender plants will not do well with cold nights, you need a min temp of about 10c

Keep them indoors until the nights get warmer

[Hole Digger]

Or if its going to be cold cover tender plants with fleece, that should do the trick

[Angry Janice]

Thanks for all of these replies. I will deinately try the water bottles and the fleece. I have Tomatoes, runner beans, chilis, tobacco, peppers, corn, lots of things. I also made the mistake... please don't die... of putting runner beans out in the garden. They've coped for three weeks so far but I am terrified of frost.