Despite its tender leaves, spinach is a tough little plant. It overwinters easily in my zone (6b in the Central Oregon high desert) without protection, and bounces back in early spring with renewed vigor.
They’re so well adapted to cold, in fact, that their seeds won’t germinate in late summer’s heat. If you want mache or miner’s lettuce in your garden, you’ll have to wait to sow until soil temperatures are 68°F or below.
The high-yielding plants are loaded with incredible flavor that only gets better the colder it turns. And that’s a plus for winter gardens, as collards easily outperform kale in terms of freeze resistance.
The key to getting cabbage to survive through winter is to start the seeds indoors in early to mid-summer (depending on your climate), then transplant in the garden in late summer.
Chard is hardy down to 15°F before needing cover. Or, you can harvest all the leaves at once and add a thick layer of mulch over the crown. The remaining crown will overwinter and regrow new leaves in spring, giving you a head start in the garden.