What to Plant in December in Zone 7

The One True Dead Month, With a Single Seed Tray Exception

Nothing goes into the ground this month, and exactly one crop even opens: celeriac, in the last days of December, and that is a seed tray on a windowsill rather than a bed. It wants around 110 days and the longest indoor lead of any root grown here, which is precisely why it starts in the coldest week of the year instead of a comfortable one. Even January, with its short list of five hardy roots and alliums, has more happening than December does; this is the point in the calendar where the zone's real winter, not just a light frost, takes hold, with nights routinely settling into the teens and low 20s.

That distinction matters here. A zone with a true winter isn't one long dead season, it's a short one wedged between two long growing stretches, and December is the narrowest part of that wedge.

Keep the Overwintering Crops Alive

Fava bean sown in September, along with the garlic and shallot cloves tucked in once frost had actually arrived, are all dormant or close to it by now, and they need almost nothing from you beyond an intact layer of mulch. Check after any hard wind that the straw hasn't blown clear of the bed.

Vent row cover on any greens still growing whenever the thermometer clears 45 degrees during the day; cover left sealed on a mild afternoon traps humidity and invites rot faster than an open bed would.

Check stored winter squash and potatoes weekly. Any squash with a soft spot goes to the kitchen this week rather than back into storage, since one spoiling fruit will take its neighbors down with it inside a month.

Order seed for next spring during any downtime this month. Popular tomato and pepper varieties routinely sell out of their more unusual cultivars by February, and a December order beats that rush entirely.

Test any leftover herb or flower seed the same way you'd test onion seed: 10 seeds on a damp paper towel folded into a bag, counting germination after 8 to 10 days rather than guessing from how the packet looks.

A hard freeze this month can also crack unprotected ceramic pots left outdoors with soil still in them. Empty and store any container not currently holding a live overwintering crop.