The practice of propagating and raising plants inside a greenhouse, cold frame, or conservatory. The glass or plastic enclosure traps solar heat, protects tender seedlings from frost, and allows growers to extend the natural growing season or cultivate tropical species in cold climates.
Heard on the job
We start all our heirloom tomatoes under glass in February so they're ready to plant out by May.
Related terms
Cold frame
A low, transparent-roofed box set on the ground to protect plants from freezing weather.
Forcing
The horticultural practice of artificially manipulating a plant's environment to induce out-of-season blooming or fruiting.
Hot bed
A glass-covered garden frame heated from below by decomposing organic matter.