What to Plant in Phoenix in January

Why January Is Critical in Phoenix

Most of the country is buried in snow in January. Phoenix gardeners are planting tomatoes. Our warm-season spring crops (tomatoes, peppers, eggplant) need to go in the ground in January or early February so they have time to produce before Phoenix heat ends the season in May–June.

Tomatoes planted in January have until late May before temperatures hit 95°F and blossom drop stops production. Tomatoes planted in March only have until late May — less than 3 months, often not enough time for a full harvest.

What to Plant in Phoenix in January: Warm-Season Crops

Transplants to Plant Now (January 15–February 15):

• Tomatoes — Buy transplants from local nurseries. Plant after January 15 when frost risk is minimal. Full guide: How to Grow Tomatoes in Phoenix
• Peppers (all types) — Jalapeños, Anaheims, bells, serranos. Same timing as tomatoes. Full guide: Peppers in Phoenix
• Eggplant — Transplants in late January. One of the best Phoenix crops. Full guide: Eggplant in the Phoenix Desert

From Seed in January:

• Onions (sets) — Plant onion sets directly in the ground January–February. Harvest in late spring.
• Basil — Transplants work best. Basil thrives alongside tomatoes in spring.
• Herbs — Oregano, chives, parsley transplants all go in January.

What's Still Producing From Fall Planting in January

If you planted a fall garden in October, January is peak harvest season for cool-season crops:

• Lettuce, kale, spinach, chard — cut-and-come-again harvesting at its best
• Broccoli and cauliflower — heads forming or ready to harvest
• Carrots and beets — ready for harvest if planted in October
• Snap peas — at peak production in January

What NOT to Plant in Phoenix in January

• Cucumbers, squash, melons, beans — Wait until late February when soil is warmer. Planted in January these will stall and struggle.
• Summer heat-lovers (okra, Armenian cucumber) — These need warm soil and won't thrive until April–May.

January Frost Risk in Phoenix

Phoenix averages 1–3 nights of frost per year, primarily in January. Most years have no frost at all. When frost is forecast:

• Cover transplants with frost cloth, old sheets, or cardboard overnight
• Remove coverings in the morning once temperatures rise above 40°F
• Don't panic — brief light frost rarely kills established transplants
• Seedlings under 4 inches tall are more vulnerable than established plants

Your January Garden Checklist

• ☐ Check local nurseries for tomato, pepper, and eggplant transplants (usually arrive in early January)
• ☐ Prepare raised bed soil — add fresh compost if needed
• ☐ Test soil moisture before planting (soil should be moist but not waterlogged)
• ☐ Install drip irrigation before planting if you haven't already
• ☐ Plant tomato and pepper transplants January 15–31
• ☐ Plant onion sets directly in soil
• ☐ Harvest remaining fall cool-season crops before they bolt in February

Frequently Asked Questions

What can I plant in Phoenix in January?

In January you can plant tomato and pepper transplants (after January 15), eggplant transplants, onion sets, basil transplants, and cool-season herbs. January is the most important planting month in Phoenix because it opens the spring growing season.

Is it safe to plant tomatoes in January in Phoenix?

Yes — after January 15 once the coldest nights have passed. Phoenix averages only 1–3 frost nights per year, usually in early January. Buying transplants from a local nursery and planting after the 15th is the recommended approach for beginners.

What should I NOT plant in January in Phoenix?

Avoid cucumbers, squash, melons, and beans in January — wait until late February when the soil is warmer. Summer crops like okra and Armenian cucumber should wait until April or May.

Why is January so important for Phoenix gardeners?

January opens the spring growing window for warm-season crops. Tomatoes and peppers need to be in the ground in January or early February to have enough time to produce before Phoenix temperatures exceed 95°F in late May — when fruit set stops entirely.

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