What to Plant in December in Zone 8

Three Crops Open, and They Are the Three Slowest

Three crops open this month, and it is no accident that they are the longest-season ones on the whole list: celeriac around the middle of December, then parsnip and leek right at the turn of the year. Celeriac and leek want 110 to 120 days and begin in a tray indoors; parsnip goes straight into cold ground, germinates slowly by nature, and is still sizing up months later. A crop that needs four months of cool weather has to start in the coldest month there is.

Beyond those three, calling December dormant would be misleading. First frost has typically already arrived by the time this month opens, and it's usually a light one, more a cold snap than the kind of hard freeze that would flatten a bed overnight. Spinach, lettuce, mache, and the fall alliums sown back in September and October keep growing right through it.

That's the real shape of winter here: not a stop, but a slowdown, with harvest continuing in some form nearly every week of the year rather than pausing outright for months at a stretch.

Keep Harvesting Through the Cold Snaps

Cut greens in the mornings after a frosty night has had time to melt off rather than while leaves are still frozen; harvesting frozen leaf tissue bruises it and shortens how long it keeps once picked.

Check stored winter squash weekly for soft spots and pull any that show one before it spreads to its neighbors. A single rotting squash in a storage bin can take down two or three others within a couple of weeks.

Use this quieter stretch to order next year's seed and test any leftover packets from last season. Wrap 10 seeds in a damp paper towel inside a bag and count sprouts after 8 days; fewer than 7 means it's worth replacing the packet before the January planting window opens again.

Prune dormant blueberry, blackberry, and currant bushes this month while they're leafless and easy to see into. Blackberry canes are biennial, not long-lived: a cane grows as a leafy primocane its first year, fruits as a floricane the second, then dies outright, so nothing on the plant is legitimately older than two seasons. Cut every cane that fruited last summer down to the ground, and thin the remaining first-year canes to 3 to 4 per linear foot of row so the planting isn't feeding wood that will never fruit again.

Check that mulch on garlic and shallot beds is still holding after any winter storm. A bare patch exposes cloves to more temperature swing than the crop needs to handle in a mild winter like this one.