Plant Onions in Zone 13b

Seed-starting, transplant & harvest dates for USDA Zone 13b

Direct sow

Feb 1

Harvest (~100d)

May 12

Zone 13b is effectively frost-free, so the Zone 13b calendar for onions is set by heat, not cold. There is no last frost to count backward from and no first frost to beat, which means the question is not whether onions will finish but whether it will sit through the hottest stretch of the year. Onions is a hardy crop needing about 100 days from sowing to harvest.

Planting onions for a fall harvest in Zone 13b

Zone 13b has no meaningful frost, so the fall and winter months are the easiest time of year to grow onions here. Sow from about October 1 onward.

Short-day onion sets planted in fall overwinter in zone 7 and warmer and bulb up months ahead of a spring planting.

Fall dates are counted backward from the Zone 13b average first frost, not forward from a sowing date. See the fall planting calendar by zone for the full method.

Spring vs fall onions in Zone 13b

Planting	Sow or start	In the ground	Harvest
Spring	Feb 1	Feb 1	May 12
Fall	Oct onward	Oct onward	Next spring

Last spring frost

Frost-free

First fall frost

Frost-free

Growing season

365 days

Onions in nearby zones

Onions in Zone 13a (colder) Full Onions grow guide Zone 13b planting calendar

Other crops in Zone 13b

Tomatoes in Zone 13b Peppers in Zone 13b Cucumbers in Zone 13b Lettuce in Zone 13b Zucchini in Zone 13b Carrots in Zone 13b Beans (bush) in Zone 13b Peas in Zone 13b Broccoli in Zone 13b Spinach in Zone 13b Kale in Zone 13b Garlic in Zone 13b Potatoes in Zone 13b Squash (winter) in Zone 13b Corn in Zone 13b Radishes in Zone 13b Beets in Zone 13b Eggplant in Zone 13b Basil in Zone 13b Cilantro in Zone 13b Parsley in Zone 13b Pumpkins in Zone 13b Sunflowers in Zone 13b

Frequently asked questions

When should I start onions in Zone 13b?

Direct sow outdoors around Feb 1.

Can I direct sow onions in Zone 13b?

Yes, direct sow around Feb 1.

Can I plant onions in the fall in Zone 13b?