Managing Temperature and Moisture in a Hotbed

A hotbed is an electric heating cable-heated cold frame designed to protect delicate plants during the cold months and harden recently started plants prior to taking them outside, or start cool-season plants early in spring. Its purpose is severalfold: protect tender plants during winter; harden off started ones before setting them outdoors; or start cool-season seeds early in spring.

Insulation should be installed around the base of a hotbed to keep cold from seeping into its growing space from soil and frame, and through soil and frame. Styrofoam insulation works just as well, although horse manure heated with bedding provides superior results.

Air Flow

Modern hotbeds usually rely on electricity for heating, though a simple wire covered cable 60 to 70 feet long will still suffice for even heating of the frame. Zigzagging across its length ensures even heating, and some thermostats may even control multiple hotbeds simultaneously.

Manure hotbeds can be created without significant expenditure of money or energy, even with electric heating systems. Simply start piling the manure ten to fourteen days before use in much the same manner as compost piles; ensure the pile is forked over properly so as to break up lumps and distribute its content more evenly.

Once the bed is in use, it should be insulated as any house foundation would be. Styrofoam or similar rigid insulation works perfectly well – simply pile it against any exposed part of its frame above ground level.