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Zone 9A — December

What to Plant in December in Zone 9A

December in Zone 9A: 33 crops to start indoors, 7 to plant or direct sow outside, and 46 entering harvest window. Last frost averages March 4. Reference city: Phoenix, AZ.
Updated May 13, 2026 · Frost data from NOAA 1991-2020 Climate Normals
33 Start Indoors
7 Plant Outside
46 Harvest
Frost risk: High

Frost risk is still high in Zone 9A. The last spring frost typically lands on March 4, with the earliest plausible clearance around February 5. Hold tender crops indoors a while longer.

See full Zone 9A frost outlook

Start Indoors in December

Plant Type Start Indoors Transplant Outside Harvest Window
Carentan Leeks allium Dec 31 Feb 18 May 19 – Jun 8
Giant Maximum Mix Snapdragon Flowers flower Dec 17 Feb 18 May 9 – May 24
Giant Musselburgh Leeks allium Dec 31 Feb 18 Jun 3
King Richard Leek allium Dec 3 Feb 4 Apr 20
Leek allium Dec 3 Feb 4 May 15 – Jun 14
OG American Flag Leeks allium Dec 31 Feb 18 May 19 – May 29
Victoria Rhubarb vegetable Dec 31 Feb 18 Perennial — see plant page
Viola and pansy edible flowers flower Dec 10 Feb 18 Apr 19 – Apr 29
Angelica herb Dec 31 Mar 4 May 23 – Jun 2
Barletta, Pearly White Onions allium Dec 31 Mar 4 May 18 – May 23
Brilliant Celeriac root vegetable Dec 17 Mar 4 Jun 22 – Jul 2
Carolina Reaper peppers pepper Dec 31 Mar 18 Jun 16 – Jul 16
Cherry Bomb peppers pepper Dec 31 Mar 18 Jun 1 – Jun 6
Curly Parsley herb Dec 31 Mar 4 May 13 – May 23
Datil peppers pepper Dec 31 Mar 18 Jun 16 – Jul 6
English Thyme herb Dec 31 Mar 4 Perennial — see plant page
English White Daisy Flowers flower Dec 31 Mar 4 Perennial — see plant page
Flat-Leaf Parsley herb Dec 31 Mar 4 May 13 – Jun 2
Golden Celery vegetable Dec 24 Mar 11 Jun 4 – Jun 14
Grano Red Onions allium Dec 31 Mar 4 Jul 2
Grano White Onions allium Dec 31 Mar 4 Jul 2
Imperial Star Artichoke vegetable Dec 31 Mar 4 Jun 2 – Jun 12
Ox-Eye Daisy Flowers flower Dec 31 Mar 4 Perennial — see plant page
Red Burgundy Onions allium Dec 31 Mar 4 Jun 22 – Jul 2
Rosemary herb Dec 31 Mar 18 Perennial — see plant page
Shasta Daisy Flowers flower Dec 31 Mar 4 Perennial — see plant page
Southport Red Globe Onions allium Dec 31 Mar 4 Jul 2
Southport White Globe Onions allium Dec 31 Mar 4 Jul 2
Spanish Sweet White Onions allium Dec 31 Mar 4 Jun 22 – Jul 2
Tall Utah 52-70 Celery vegetable Dec 31 Mar 18 Jun 26 – Jul 26
Tendercrisp Celery vegetable Dec 24 Mar 11 Jun 9 – Jun 24
Tepin Hot Peppers pepper Dec 24 Mar 11 Jul 9 – Sep 27
Trinidad Moruga Scorpion peppers pepper Dec 31 Mar 18 Jun 6 – Jul 16

Plant Outside in December

Plant Type Action Target Date Harvest Window
Asian Tempest Garlic allium Plant Out Dec 6 May 21, 2027 – Jun 30, 2027
Chengdu Garlic allium Plant Out Dec 6 May 21, 2027 – Jun 30, 2027
Creole Red Garlic allium Plant Out Dec 6 May 21, 2027 – Jun 30, 2027
Elephant Garlic allium Plant Out Dec 6 Jun 1, 2027 – Jun 30, 2027
Inchelium Red Garlic allium Plant Out Dec 6 May 21, 2027 – Jun 30, 2027
Mild French Garlic allium Plant Out Dec 6 May 21, 2027 – Jun 30, 2027
Softneck Garlic allium Plant Out Dec 6 May 21, 2027 – Jun 30, 2027

Harvest in December

Plant Type Planted / Sown Harvest Window
All Year Round Cauliflower (fall planting) brassica Oct 1 Dec 5
All Year Round Lettuce (fall planting) lettuce Oct 1 Dec 13
Bouquet Dill (fall planting) herb Oct 1 Dec 5
Butterhead Lettuce (fall planting) lettuce Oct 1 Dec 5
Calabrese Broccoli (fall planting) brassica Oct 1 Dec 5
California Bluebell (fall planting) flower Oct 1 Dec 5
Chantenay Carrots (fall planting) root vegetable Oct 1 Dec 10
Charleston Wakefield Cabbage (fall planting) brassica Oct 1 Dec 10
Copenhagen Cabbage (fall planting) brassica Oct 1 Dec 5
Curly Kale (fall planting) lettuce Oct 1 Dec 5
Dark Green Romaine Lettuce (fall planting) lettuce Oct 1 Dec 10
Early Purple Broccoli (fall planting) brassica Oct 1 Dec 5
Endive / Escarole (fall planting) lettuce Oct 1 Dec 5
Evergreen Bunching Onions (fall planting) allium Oct 1 Dec 5
German Chamomile (fall planting) herb Oct 1 Dec 5
Golden Acre Cabbage (fall planting) brassica Oct 1 Dec 5
Golden Beet (fall planting) root vegetable Oct 1 Dec 5
Green Arrow Pea (fall planting) legume Oct 1 Dec 10
Igloo Cauliflower (fall planting) brassica Oct 1 Dec 10
Kuroda Carrots (fall planting) root vegetable Oct 1 Dec 10
Lacinato Kale (fall planting) lettuce Oct 1 Dec 5
Little Marvel Pea (fall planting) legume Oct 1 Dec 3
Love-in-a-Mist Flowers (fall planting) flower Oct 1 Dec 10
Mammoth Dill (fall planting) herb Oct 1 Dec 5
Michihili Cabbage (fall planting) brassica Oct 1 Dec 10
Napa Cabbage (fall planting) brassica Oct 1 Dec 10
Nutri-Red Carrots (fall planting) root vegetable Oct 1 Dec 10
Oregon Sugar Pod Snow Pea (fall planting) legume Oct 1 Dec 8
Paris Market Carrots (fall planting) root vegetable Oct 1 Dec 5
Progress No. 9 Shelling Pea (fall planting) legume Oct 1 Dec 2
Purple Haze Carrots (fall planting) root vegetable Oct 1 Dec 13
Rapeseed Cover Crop (fall planting) cover crop Oct 1 Dec 10
Rapini Broccoli Raab (fall planting) brassica Oct 1 Dec 5
Red Romaine Lettuce (fall planting) lettuce Oct 1 Dec 10
Scarlet Flax Flowers (fall planting) flower Oct 1 Dec 10
Shelling Pea (fall planting) legume Oct 1 Dec 10
Snow Pea (fall planting) legume Oct 1 Dec 10
Snowball Self-Blanche Cauliflower (fall planting) brassica Oct 1 Dec 5
St. Valery Carrots (fall planting) root vegetable Oct 1 Dec 10
Tendersweet Carrots (fall planting) root vegetable Oct 1 Dec 10
Tom Thumb Lettuce (fall planting) lettuce Oct 1 Dec 10
Vienna Purple Kohlrabi (fall planting) brassica Oct 1 Dec 5
Viola and pansy edible flowers (fall planting) flower Oct 1 Dec 10
Violetta Purple Cauliflower (fall planting) brassica Oct 1 Dec 5
Wando Pea (fall planting) legume Oct 1 Dec 8
Watermelon Radishes (fall planting) root vegetable Oct 1 Dec 5

Key Tasks for December in Zone 9A

  1. 1 Start 33 varieties indoors this month under grow lights or in a sunny south-facing window. Use a seed-starting mix and bottom heat (70–75°F) for best germination rates.
  2. 2 Check soil moisture before watering — stick a finger 2 inches into the soil. Water only when the soil is dry at that depth. Consistent moisture is more important than frequency.
Back to full Zone 9A planting calendar
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