My Planting Calendar

What to plant in December in Arizona

In Arizona (AZ), December sits about 13 weeks before the average last frost (March 15). The state averages 245 frost-free days a year (last frost March 15, first frost November 15; USDA zones 4b, 5b, 6b, 7b, 8b, 9b, 10b).

7 crops have a sowing or planting window this month, including shallot, garlic - and 2 of those windows close during December.

Dates here come from Arizona frost dates (last frost Mar 15, first frost Nov 15). For one crop in detail, see when to plant garlic, onion or tomato in Arizona.

A planning monthSow or plant: 7Start indoors: 5Harvesting: 10

Arizona covers a very wide range of climates, so dates near you can be two weeks or more either side of these. Enter your ZIP code in the planting calendar for dates tuned to your town.

Arizona: planting activity through the year

29
65
90
58
9
9
11
19
31
8
2
7
JanFebMarAprMayJunJulAugSepOctNovDec
Frost riskFrost-free: Mar 15 – Nov 15
Bars count the vegetables, herbs and fruit with a sowing or planting window in each month, from the state’s average frost dates. 7 have one in December; the busiest month is March (90).

Last chance in December

Shallot (plant in fall (after first frost), by Dec 6) · Garlic (plant in fall (after first frost), by Dec 13)

For fall and winter harvests (2)

Sowings counted back from Arizona's first fall frost, so the crop matures before the cold - or, for garlic and similar, planted after it.

CropWhat to doWindowThis month
ShallotPlant in fall (after first frost)Nov 19 – Dec 6Last chance - ends Dec 6
GarlicPlant in fall (after first frost)Nov 26 – Dec 13Last chance - ends Dec 13

Start seeds indoors in December (5)

Indoor sowings for transplants later. Six to eight weeks under lights is typical for tomatoes and peppers; onions and leeks need longer.

CropWhat to doWindowThis month
CeleriacStart seeds indoorsDec 21 – Jan 4Opens Dec 21
CeleryStart seeds indoorsDec 28 – Jan 11Opens Dec 28
LeekStart seeds indoorsDec 28 – Jan 11Opens Dec 28
OnionStart seeds indoorsDec 28 – Jan 11Opens Dec 28
RosemaryStart seeds indoorsDec 28 – Jan 11Opens Dec 28

Harvesting in December

First harvests expected this month from crops sown or planted on time earlier in the season.

Cabbage · Oct 5 – Dec 1Radicchio · Oct 19 – Dec 15Turnip · Oct 27 – Dec 3Chervil · Oct 27 – Dec 3Borage · Nov 4 – Dec 11Parsley · Nov 5 – Dec 12Green Onion / Scallion · Nov 9 – Dec 16Watercress · Nov 13 – Dec 10Endive & Escarole · Nov 20 – Dec 22Fava Bean (Broad Bean) · Nov 24 – Dec 26

Planting dates for popular crops in Arizona

Every crop has its own full-year dates for Arizona: indoor start, transplant or direct sowing, and harvest.

When to plant garlic in Arizona →When to plant onion in Arizona →When to plant tomato in Arizona →When to plant lettuce in Arizona →When to plant bell pepper in Arizona →When to plant carrot in Arizona →When to plant pea in Arizona →When to plant spinach in Arizona →Arizona frost dates by zone →

Spring bulbs to plant in December in Arizona

Tulips, daffodils, hyacinths and crocus are planted in fall, once the soil has cooled and before it freezes. The exact window depends on the state, so our bulb guide quotes what each extension service says.

Bulb planting guide by state, with depth and spacing →When to plant daffodils →When to plant tulips →

A planning month: December garden jobs in Arizona

  1. Order seed while stock is good. Arizona's average last frost is March 15, so the first indoor sowings begin around December 21 - see starting seeds indoors.
  2. Sketch this year's beds and move each crop family to a new spot - the garden planner and the crop rotation guide make it quick.
  3. Test old seed: roll ten seeds in a damp paper towel for a week. If fewer than seven sprout, sow thicker or buy fresh.
  4. If the ground isn't frozen, spread compost now so it's worked in by spring, and send off a soil test - December is when labs are quiet.

USDA zone chart for Arizona

Arizona spans USDA zones 4b, 5b, 6b, 7b, 8b, 9b, 10b. Colder zones, usually higher or further inland, have a later last spring frost and an earlier first fall frost than the state average.

ZoneLast frostFirst frostSeason
Zone 4May 10Sep 25135 days
Zone 5Apr 30Oct 5160 days
Zone 6Apr 15Oct 15185 days
Zone 7Apr 5Oct 25200 days
Zone 8Mar 20Nov 5230 days
Zone 9Feb 20Nov 30280 days
Zone 10Jan 30Dec 15330 days

Questions gardeners ask

What vegetables can I plant in Arizona in December?

7 crops have a window in December: shallot, garlic, celeriac, celery, leek, onion, rosemary. The tables above give the exact dates for each.

Is it too late to plant tomatoes in Arizona in December?

For this year, yes - the tomato windows in Arizona have closed. The next step is to start seeds indoors from about January 18.

Is it too late to plant lettuce in Arizona in December?

For this year, yes - the lettuce windows in Arizona have closed. The next step is to start seeds indoors from about February 8.

When is the first frost in Arizona?

The statewide average first fall frost is around November 15 and the last spring frost around March 15. Arizona covers a wide range of climates, so local dates can differ by two weeks or more - look yours up by ZIP code.

What should I start indoors in December in Arizona?

Celeriac (Dec 21 – Jan 4), Celery (Dec 28 – Jan 11), Leek (Dec 28 – Jan 11), Onion (Dec 28 – Jan 11), Rosemary (Dec 28 – Jan 11).

← November in ArizonaJanuary in Arizona →Full-year Arizona planting calendar →Arizona frost dates →

What to plant in December in other states

AlabamaCaliforniaColoradoFloridaGeorgiaIllinoisIndianaKentuckyAll states →

Dates are computed from Arizona’s statewide average frost dates (from NOAA/NCEI climate normals) and each crop’s timing in our crop database. Your garden may be a week or two either side - for dates tuned to your ZIP code, use the planting calendar.