Local planting guide · Southwest
zip 85069
Phoenix is in USDA hardiness zone 9b, with average winter lows of 25°F to 30°F. The local growing season runs roughly 01/05 through 01/03 (~365 days). This zip falls within the Southwest growing region.
- USDA zone
- 9b 25°F to 30°F
- Last spring frost
- 01/05
- First fall frost
- 01/03
- Growing season
- 365 days
- Compatible crops
- 37
- Growing region
- Southwest
Right now in Phoenix
Week 18 priorities
On the docket: transplant out after last frost · direct sow after last frost. See the full calendar →
Gardening in Phoenix
Phoenix sits in the hottest part of zone 9b, where winter frost barely registers but summer heat dominates every growing decision. With no hard frost risk and a 365-day growing season, the constraint is not survival through cold but endurance through heat. Temperatures routinely exceed 110°F from June through August, which kills or sterilizes most cool-season crops and stresses even heat-lovers like tomatoes and peppers. The gardening calendar runs nearly backwards from northern zones: the primary growing season is October through April, when temperatures drop to pleasant ranges and frost danger is negligible. Figs, pomegranates, Asian persimmons, and jujubes thrive because they evolved for hot climates and tolerate the alkaline, low-humidity desert soil. Tomatoes, sweet peppers, and hot peppers succeed in Phoenix but require careful varietal selection and strategic timing to avoid the worst of the summer heat.
Regional context · Southwest
What the Southwest brings to Phoenix
Hot, arid, irrigated. Two growing seasons in the low desert: cool October to April, hot May to September. Date palms and citrus thrive at low elevation; apples and stone fruit at higher elevations. The chile-pepper belt of the country.
Common challenges
Issues that most often defeat home gardeners in zone 9b, drawn from the broader USDA zone profile.
- ▸ Heat stress in summer
- ▸ Insufficient chill for most apples
- ▸ Salt spray near coasts
What defeats new gardeners in Phoenix
Summer heat is the binding constraint. From June onwards, nighttime temperatures rarely drop below 80°F, causing cool-season crops to bolt and preventing fruit set in heat-sensitive vegetables like tomatoes and peppers. A second challenge is water scarcity; Phoenix's desert location means consistent irrigation is essential year-round, and water restrictions often conflict with peak summer demand. The monsoon season (July-September) brings rare but intense humidity and occasional fungal disease pressure. Soil pH is chronically high (7.5 to 8.5 across much of Phoenix), requiring sulfur amendments to grow acid-loving crops. Finally, brief frost risk in January and early February can damage tender new growth if plants have already broken dormancy in response to mild winter temperatures.
Crops that grow in Phoenix
37 crops from our catalog match zone 9b, grouped by type.
Tree fruit
11 crops
zone 9b Fig
Ficus carica
zones 7a–10b
zone 9b Asian Persimmon
Diospyros kaki
zones 7a–10a
zone 9b Pomegranate
Punica granatum
zones 7b–10a
zone 9b Jujube
Ziziphus jujuba
zones 6a–9b
zone 9b Lemon
Citrus limon
zones 9a–11b
zone 9b Orange
Citrus sinensis
zones 9a–11b
zone 9b Lime
Citrus aurantiifolia
zones 9b–11b
zone 9b Grapefruit
Citrus paradisi
zones 9a–11b
Berries
2 crops
Vegetables
18 crops
zone 9b Tomato
Solanum lycopersicum
zones 3a–10b
zone 9b Sweet Pepper
Capsicum annuum
zones 4a–10b
zone 9b Hot Pepper
Capsicum species
zones 4a–10b
zone 9b Eggplant
Solanum melongena
zones 5a–10b
zone 9b Cabbage
Brassica oleracea var. capitata
zones 3a–9b
zone 9b Kale
Brassica oleracea var. acephala
zones 3a–9b
zone 9b Collards
Brassica oleracea var. acephala
zones 4a–9b
zone 9b Cucumber
Cucumis sativus
zones 3b–10a
Herbs
6 crops
Plan the year
Planting calendar for Phoenix
Year-view of seed starting, transplanting, planting, pruning, fertilizing, harvest, and pest-watch windows tuned to Phoenix's local frost dates.
Week ? · loading
This week in Phoenix, AZ (zone 9b)
Quiet week in Phoenix, AZ (zone 9b). this week is a good time to step back and plan ahead.
Nothing critical on the calendar this week.
187 bars · 37 crops
Calendar logic combines NOAA frost normals with crop-specific timing data. Local microclimate and weather always overrules the calendar; use this as a starting point.
Top pests for zone 9b
Ranked by how many crops in your zone they affect. Click through for IPM controls and signs to watch for.
Multiple species (Aphididae)
Small soft-bodied sap-sucking insects that reproduce explosively in spring. Excrete honeydew that supports sooty mold and attracts ants. Transmit viral diseases.
Multiple species (Aleyrodidae)
Tiny white moth-like flying insects that feed on plant sap and excrete honeydew. Transmit numerous viral diseases including tomato yellow leaf curl virus.
Meloidogyne species
Microscopic soil-dwelling worm that forms galls on roots, reducing vigor and yield.
Tetranychus urticae
Tiny mite that feeds on leaf undersides, causing stippling and webbing during hot dry weather.
Multiple species (Chrysomelidae)
Tiny black or bronze jumping beetles that put hundreds of small holes in seedling leaves. Most damaging on direct-seeded brassicas and young eggplant.
Odocoileus species
Whitetail and mule deer browse can devastate orchards and gardens, particularly in winter when food is scarce. Antler rub on young trunks kills saplings outright.
Pseudococcidae spp.
Soft white waxy insects that cluster at leaf joints, fruit stems, and root crowns. Honeydew secretion supports sooty mold; root mealybugs cause decline that mimics drought.
Coccoidea spp.
Sap-sucking insects that attach to bark, leaves, and fruit, secreting honeydew that fuels sooty mold. Heavy infestations weaken trees and cause leaf yellowing.
Top diseases for zone 9b
Ranked by how many crops in your zone they affect. Click through for symptoms, controls, and resistant varieties.
Pseudoperonospora cubensis (cucurbits) and others
Water mold (oomycete, not a true fungus) that thrives in cool damp conditions. Spreads rapidly through cucurbit and brassica plantings on wind-borne spores.
Cucumber mosaic virus, Tobacco mosaic virus, and others
Family of plant viruses producing mottled yellow-and-green leaf patterns. Vectored primarily by aphids; some are seed-transmitted or spread by handling tools and tobacco products.
Pythium and Rhizoctonia species
Soil-borne complex of water molds and fungi that kill seedlings before or shortly after emergence. The single most common cause of seed-starting failures.
Fusarium oxysporum
Soil-borne fungal disease that plugs vascular tissue and kills affected plants. Persists in soil for many years; impossible to eliminate once established.
Sclerotium rolfsii
Soil-borne fungal disease most damaging in warm humid Southern conditions. White mycelial fans and small mustard-seed-sized sclerotia at the soil line are diagnostic.
Calcium deficiency physiological disorder
Not a true disease but a calcium-uptake disorder caused by inconsistent soil moisture during fruit development. The dominant cause of damaged first-fruit on home tomato plantings.
Capnodium spp.
Black fungal coating that grows on honeydew secreted by aphids, scale, mealybugs, and whiteflies. Doesn't infect plant tissue directly but blocks photosynthesis and disfigures fruit.
Tomato spotted wilt orthotospovirus (TSWV)
Virus vectored by thrips, particularly western flower thrips. Wide host range and growing global distribution. No cure once infected.
Companion planting suggestions
Beneficial pairings drawn from companion data, filtered to crops that grow in zone 9b.
- Fig + Rosemary
Rosemary tolerates the dry sites figs prefer and provides aromatic pest deterrence.
- Tomato + Basil
The classic Italian pairing. Basil's volatile oils are reported to repel hornworms and whiteflies, and the two crops share the same warm-season schedule and water needs. Plant basil between tomato cages.
- Sweet Pepper + Basil
Same warm-season culture, same watering schedule. Basil reportedly improves pepper flavor and repels aphids and thrips that are pepper's primary pests.
- Hot Pepper + Basil
Compatible heat-loving culture, similar water needs. Basil interplanted between hot pepper plants supports beneficial insects and reduces aphid pressure.
- Lettuce + Tomato
Lettuce planted at tomato's base benefits from afternoon shade as the tomato grows, extending the lettuce harvest into early summer. Different root depths avoid competition.
- Cabbage + Onion
Onion smell confuses cabbage moth. Both prefer similar moisture and fertility. The onion-cabbage interplanting is a Northern European tradition.
Soil types reference
Soil texture and pH decide what grows easily on your specific lot. Find the closest match below for crop recommendations and amendment guidance.
Practical tips for Phoenix
First, reverse the typical planting calendar. Tomatoes, peppers, and squash sown in mid-to-late August produce fall and winter harvests, avoiding peak summer. Cool-season crops (brassicas, leafy greens, herbs) thrive from October through March and should be prioritized; this 6-month window is Phoenix's true growing season. Second, deploy 30-50% shade cloth from May through September. Even heat-lovers like figs and pomegranates benefit from afternoon shade during the worst of the heat, improving fruit quality and reducing water stress. Third, choose varieties bred for heat and dry climates. Early-maturing and heat-tolerant tomato varieties, heirloom pepper types from arid regions, and desert-native figs outperform standard varieties, reducing both water demand and maintenance.
Frequently asked questions
- When is the best time to garden in Phoenix?
October through April. Nighttime temperatures drop to 40-70°F, daytime highs are 60-85°F, and frost risk is minimal. This is when most vegetables thrive. Avoid planting warm-season crops May through September except for heat-lovers like okra and eggplant.
- Can you grow tomatoes in Phoenix?
Yes, but with careful timing. Plant in August or September for fall and winter harvests. If planting in spring, choose early-maturing, heat-tolerant varieties and harvest before June. Avoid starting tomatoes in March or April for summer crop; they won't set fruit in 110°F+ heat.
- What are the best year-round crops for Phoenix?
Figs, pomegranates, Asian persimmons, jujubes, and goji berries tolerate heat and alkaline soil, producing fruit year-round with minimal care. In winter and spring, add tomatoes, peppers, squash, brassicas, and leafy greens. Summer options are limited to okra, eggplant, and heat-loving herbs.
- How much water do Phoenix gardens need?
Phoenix is a desert with minimal annual rainfall, so irrigation is essential year-round except during rare summer rains. Established fruit trees need deep, infrequent watering. Vegetables need consistent moisture, especially during spring and summer. Drip irrigation is more efficient than overhead watering.
- Is frost a risk in January and early February?
Minimal, but not zero. Phoenix's location in zone 9b means hard freezes below 25°F are rare. Occasional frost dips to 32-28°F can occur. Protect tender new growth and sensitive crops like pepper seedlings during these brief cold snaps; the risk passes quickly.
- Why do peppers fail in Phoenix summers?
Peppers stop setting fruit when nighttime temperatures exceed 75-80°F consistently, which happens by June. Grow peppers in fall and winter instead. If planting in spring, choose heat-tolerant varieties and use shade cloth from May onwards to lower plant temperature by 10-15°F.
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Frost data: NOAA Climate Normals 1991-2020, station USW00023183. Local microclimates can shift these dates by a week or more.
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