How to overwinter radicchio 'rossa di treviso'

No hardiness zone is recorded for radicchio 'rossa di treviso'; it prefers to stay above about 10°C (50°F) while in growth, so treat it as frost-tender unless you know otherwise for your area. Radicchio 'Rossa di Treviso' will take cool conditions but not a hard freeze, so the aim is a frost-free winter rather than a warm one. An unheated greenhouse, porch, conservatory or bright garage all work well. Keep it cool, bright and on the dry side, and it will hold steady until growth restarts in spring.

Move under cover before the first hard frost; back outside after the last spring frost.

Water only occasionally — enough that the rootball never dries out completely, no more. No feeding until spring growth begins.

Bringing radicchio 'rossa di treviso' into a warm living room. Too much winter warmth forces weak, pale growth that collapses when it goes back outside — cool and bright beats warm and dim.