any way i can keep the frost off them?

hi all,
i have three absolute monsters planted up in a spot where no one ever goes. These babies are all female and all over 6 foot tall and really, really bushy. Unfortuantly when i checked on them today it looked like that had only been budding for a week. Where i live the frosts will probably start in about a month -maybe less- and they wont be ready to crop then. Does anyone know of any ways i can keep these plants safe from frost if i need too?
Because of where they are growing it isnt possible for me to visit them very often so it would need to be a perminant solution that wouldnt require me visiting them everyday. i know im clutching at straws but i was hoping someone had come up with a clever idea somewhere along the line.
oh yeah: i live in england and its unlikely it will get really, really cold but it will probably freeze a bit.
thanks for ur time.

Where I live they grow a lot of shade tobacco where they use a white woven mesh type material that lets in the sun to sort of tent the plants. I don't know if you can get anything of the sort where you live but you could use that to tent your plants, this would protect them from weather and blanket them from frost.
The down side to this is you may have to bend your plants over a tad so the tent is not so high, and it will definately stick out like a sore thumb. If these two things do not concern you than it would definately suit your purpose

Yeah, they grow shade tobacco around here too with those tents and I recommend using that.
It's harder that your plants are far from your house, otherwise you could just toss a stealthy green sheet over them on nights when a frost is predicted, and remove it in the morning. That would be more stealthy, but require you to watch the weather like a farmer.

i use the frame from one of those picnic cabana's and cover with a tarp on frosty nights. it helps too to lightly water the ground before covering (not the plants!) as the evaproation process works in reverse so it warms the air inside the tarp above outside air temp...it will raise the temps a couple very important degress. if it gets any colder i use a space heater.

cheers for the replies guys. I may have to look into getting some thing to shade it with then but im not really sure it is sutible, hmmmmmm. Might just pray for no frosts, lol.