I need a coldframe to grow a couple of winter tender bulbs from South Africa. I have some problems growing them indoors - the flowers frequently blast and shrivel before opening - probably due to low humidity and warm air temperature.

I was considering making a small coldframe to place on my exposed porch. The bulbs grow and flower in early winter (they should be done in the next few weeks), and Zone 6 in New Jersey doesn't really get cold until mid January, so I think I MIGHT get away with this.

I was thinking of using a fishtank on its side (opening towards the house) with a thermostaicially controlled heating pad for bottom heat as the container. I figured that the open back would allow some temperature control, and the bottom heat could keep thinga bove freezing (that's all I need).

I could just put them in my regular coldframe, but then I would have no way of bringing them indoors without killing off everything out there when they flower.

Do you think it will work?

Joe 'do you have a better idea?' DeRosa