What to plant in December — zone 9a
Zone 9a averages its last spring frost around February 28 and its first fall frost around December 5. Everything below is timed from those two dates, so it stays useful whether you're planting for summer or for a fall harvest.
Start indoors
- Sow microgreens indoorsaround Dec 6
A tray on the windowsill gives you a cut of fresh greens every 10-14 days through the cold months.
- Start onions and leeks indoorsaround Dec 20
Alliums need 10-12 weeks under lights before they go out — the earliest sowing of the year.
- Onionaround Dec 20
10 weeks of indoor growth before your last frost (02-28). Match day-length to your latitude — long-day north of 37°, short-day south.
- Rosemaryaround Dec 20
10 weeks of indoor growth before your last frost (02-28). In zone 6 and below, grow in a pot and overwinter indoors near a south window.
Dormant care
- Prune dormant fruit treesaround Dec 13
Prune apples, pears and peaches while fully dormant — open the center, remove crossing wood.
Turn this into your own calendar
Get the full 12-month version for your exact ZIP — every sowing, transplant, and harvest window, with reminders you can add to your calendar. Free, no account needed to try.