What to Plant in December in Zone 10

The biggest planting window of the year opens this month

December is when zone 10's widest planting window actually opens, not when it closes. Better than 40 crops are workable here this month, against roughly 17 in zone 9 just to the north, and the difference is simply that the pockets of zone 10 seeing any frost at all typically don't see it before mid-December. It arrives in three waves: shallot, salsify, tatsoi and mizuna from around the 6th, the brassicas and the peas from the 10th, then the widest wave of all on the 24th, when lettuce, carrot, beet, radish, turnip, kale, collards, kohlrabi, arugula, cilantro and parsley all open together.

The crops closing out this month are the slow ones that started in autumn, and they are easy to miss because everything else is opening around them. Celeriac shut at the beginning of December, chervil around the 1st, and parsnip and leek both run to the 20th. If those are on your list this is the last of them until next autumn rather than the start, so treat the 20th as a real deadline. Shallot is the opposite case, opening on the 6th and running into January.

Chores that fit around the planting

The rest of the job list is dormant-season upkeep, worked in around the sowing rather than instead of it: walk fruiting shrubs and prune out anything damaged, crossing, or diseased, then sharpen and oil hand tools before weeks of lighter use dull their edges with rust rather than wear.

Order seed for the coming year's big planting push now rather than in January; popular low chill blueberry and southern highbush varieties, along with early tomato varieties suited to zone 10's fast moving spring, tend to sell out of seed and nursery stock well before the January rush begins.

A final check on stored crops

Winter squash, sweet potato, and any stored alliums need checking on a monthly rhythm here too, but the mild, humid air makes it more urgent than it sounds. A soft spot that would sit stable in a drier, colder pantry spreads through a whole bin fast in this climate, so pull anything mushy or off-smelling the moment you notice it rather than waiting for the next scheduled check.