If you’re wondering when to plant lettuce in Arizona, you’ve come to the right place. The key to success in our unique climate is all about timing, and getting that right makes growing crisp, fresh lettuce surprisingly simple.
Our desert state offers two fantastic lettuce seasons. You can grow it in the cool of fall and winter, and again in the early spring. The trick is avoiding the intense summer heat, which causes lettuce to bolt and turn bitter.
This guide will walk you through the best planting times for every region of Arizona. We’ll cover specific month-by-month schedules, variety recommendations, and simple tips to ensure a bountiful harvest from your garden.
When to Plant Lettuce in Arizona – Best Planting Times for
Your planting schedule in Arizona depends almost entirely on where you live. The state has three major climate zones, each with its own ideal window for lettuce.
Understanding Arizona’s Growing Zones
Arizona isn’t just one big desert. Elevation creates distinct gardening areas.
- Low Desert (Phoenix, Tucson, Yuma): This is USDA zone 9b. Winters are mild, but summers are extremely hot. Your main planting is in the fall for a winter harvest, with a second chance in late winter for a spring crop.
- Intermediate/High Desert (Prescott, Sierra Vista): Falling into zones 7b-8a, these areas have colder winters but milder summers. Planting is shifted later in fall and earlier in spring compared to the low desert.
- Mountain Regions (Flagstaff, Payson): These are zones 6a-7a. They have a short, cool summer perfect for lettuce, but a very short growing season. Planting happens in late spring for a summer harvest.
Low Desert Planting Calendar
For Phoenix and surrounding areas, heat is your biggest challenge. Lettuce seeds need cool soil to germinate.
- Fall Planting (Primary Season): Start seeds indoors or in shade in late August through September. Transplant seedlings to the garden from October through November. This gives you harvests all winter long.
- Spring Planting (Secondary Season): Direct sow seeds or transplant in late January through mid-February. You must harvest before the heat of May sets in. Using shade cloth from April onward can extend your season by a few weeks.
Best Low Desert Lettuce Varieties
- Black Seeded Simpson (loose-leaf)
- Romaine (Parris Island Cos is reliable)
- Butterhead (Bibb or Tom Thumb)
- Heat-tolerant hybrids like Jericho or Nevada
Intermediate & High Desert Planting Calendar
With colder winters, your fall planting needs to be timed so plants mature before hard freezes, and spring planting happens after the last frost.
- Fall Planting: Direct sow seeds in the garden in early to mid-September. You can use cold frames or row covers to protect plants through winter frosts and harvest smaller leaves.
- Spring Planting: Sow seeds directly as soon as the soil is workable, typically from mid-March to early April. You’ll have a nice harvest in late spring and early summer.
Mountain Region Planting Calendar
Here, you have one classic summer season. The goal is to plant after the last frost and harvest before the first fall frost.
- Spring/Summer Planting: Start seeds indoors 4-6 weeks before your last expected frost (often late May or June). Transplant seedlings outdoors in late May or early June. You can succession plant every two weeks through July for a continuous harvest.
Step-by-Step Planting Guide
Follow these simple steps for healthy lettuce, no matter your location.
1. Preparing Your Soil
Lettuce has shallow roots and prefers light, fertile soil. Work in 2-3 inches of compost or well-rotted manure before planting. The soil should drain well but retain moisture. A pH between 6.0 and 7.0 is ideal.
2. Planting Seeds or Transplants
- For Seeds: Sow seeds ¼ inch deep. Space them about 1 inch apart in rows, or scatter them for a broadcast bed. You can always thin them later.
- For Transplants: Gently separate seedlings. Plant them at the same depth they were growing in their container. Space plants 6-12 inches apart, depending on the variety’s mature size.
3. Watering Correctly
Consistent moisture is non-negotiable for tender lettuce. Water deeply at the base of the plants in the morning. Avoid wetting the leaves to prevent disease. In Arizona’s dry air, you may need to water every other day or even daily during warmer periods. Mulching with straw or shredded leaves helps tremendously with moisture retention.
4. Providing Shade & Protection
This is an Arizona gardening secret weapon. Use 30-50% shade cloth over your lettuce beds from late spring and for fall-planted seedlings. It can lower the temperature by 10 degrees or more, preventing bolting. In mountain areas, use floating row covers to protect from early fall frosts.
Common Problems and Solutions in Arizona
- Bolting: When lettuce sends up a flower stalk, it’s a reaction to heat or long days. The leaves become bitter. Solution: Choose slow-bolt varieties, plant at the correct time, and use shade cloth.
- Tip Burn: Brown edges on leaves often indicate inconsistent watering or a calcium deficiency in the soil. Solution: Maintain even soil moisture and ensure your compost is well-balanced.
- Pests: Aphids and slugs can be issues. Solution: Blast aphids off with water. For slugs, use diatomaceous earth or beer traps in the cooler, damp seasons.
Harvesting Your Lettuce
You can harvest lettuce in two main ways. For loose-leaf varieties, snip outer leaves with scissors, allowing the center to keep producing. This is called “cut-and-come-again.” For head lettuce (like romaine or butterhead), wait until the head feels firm and full, then cut the entire plant at the base. Always harvest in the cool morning for the crispiest leaves.
FAQ: Planting Lettuce in Arizona
Can you grow lettuce in Arizona summer?
It is very challenging in the low and intermediate deserts. The heat causes immediate bolting. In the mountains, summer is the prime growing season. Elsewhere, it’s best to focus on fall and spring.
What is the best month to plant lettuce in Phoenix?
The absolute best time to transplant seedlings into your Phoenix garden is October. For spring, aim for late January planting.
How do you keep lettuce from bolting in Arizona?
Use shade cloth, plant at the correct time, select heat-tolerant or slow-bolt varieties, and keep the soil consistently moist. Mulch is also a great help.
Can I grow lettuce in pots in Arizona?
Absolutely! Container gardening is excellent for lettuce. Use a pot at least 6-8 inches deep with drainage holes. You can move the pots into partial shade as the weather warms up, which is a big advantage.
Is it to late to plant lettuce in March?
It depends on your zone. In the low desert, March is too late for spring planting—it’s getting to warm. In the high desert, March is perfect for sowing seeds. In the mountains, March is for starting seeds indoors.
Growing lettuce in Arizona is a rewarding experience when you work with the seasons, not against them. By following these regional calendars and providing a little shade, you can enjoy homegrown salads for much of the year. Remember, the most important step is getting those seeds in the ground at the right time. Your future salads will thank you for it.