Local planting guide · Southwest
zip 85043
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 at the warm end of USDA zone 9b, where winter lows rarely drop below 25-30°F. This creates an unusual advantage: a 365-day growing season with essentially no traditional frost risk. However, heat, not cold, is the dominant constraint.
The city's climate divides into two distinct growing windows. Fall through spring (October to May) offers mild temperatures suited to warm-season crops like tomatoes, peppers, and melons, as well as Mediterranean crops such as figs and pomegranates. Summer (June to September) is severe. Temperatures regularly exceed 110°F, and most vegetables simply cease producing. Summer is better spent establishing trees and shrubs adapted to extreme heat than trying to maintain vegetable production.
Crops well-suited to Phoenix include heat-lovers with narrow production windows before peak summer (tomatoes, peppers), Mediterranean and Asian fruits that thrive during the long, dry season (fig, Asian persimmon, jujube, pomegranate), and drought-tolerant berry crops like goji. Low humidity and intense sun create ideal conditions for crops demanding well-drained soil and full sun, while posing challenges for those requiring consistent summer moisture.
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
Phoenix gardeners encounter three recurring obstacles. First, summer heat sharply reduces crop productivity: tomatoes and peppers flower readily through spring but cease flowering once temperatures exceed 95°F, and stop setting fruit entirely above 105°F. Second, the desert's naturally alkaline soil and low organic matter require consistent amendment to establish productive gardens. Most Phoenix soils range pH 7.5-8.0, while many vegetables prefer 6.5-7.0. Third, water restrictions in the Phoenix area constrain irrigation frequency, making drip systems essential and mulch non-negotiable. Overwatering to compensate often invites root disease in the low-humidity environment.
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
Late winter and early spring (February through March) offer the optimal window for tomato and pepper planting, allowing plants to mature and flower before June heat arrives. Varieties bred for heat tolerance perform more reliably than standard temperate selections in the Phoenix climate. Shade cloth at 30-50% density, applied from mid-May onward, reduces sunscald while maintaining flowering. The fall planting window (late August through early September) enables a second productive cycle, extending harvests from October through May. This double-cropping approach is essential to productive gardening in Phoenix, since summer heat effectively eliminates single-season production patterns common in temperate zones.
Frequently asked questions
- What grows best in Phoenix?
Heat-tolerant fruits and vegetables dominate local gardens: tomatoes and peppers in spring windows, figs and pomegranates year-round, jujubes and Asian persimmons for long-season crops. Goji berries thrive in the low humidity. Cool-season crops such as lettuce and broccoli perform well in fall and winter.
- When should I plant tomatoes and peppers in Phoenix?
Late winter (February to March) for spring harvest before summer heat peaks. Late August to early September for fall harvest from October onward. Each window supports roughly three to four months of reliable production.
- Is frost really not a concern in Phoenix?
Hard freezes are rare in zone 9b Phoenix, with average winter lows of 25-30°F occurring infrequently around early January. Frost management is minimal. Heat management, which limits production, is the actual crop-limiting factor in the area.
- Why does my garden stall during summer?
Temperatures above 95°F cause many warm-season vegetables to stop flowering and setting fruit. Peak summer heat at 110°F and above is simply beyond the tolerance of most vegetables. Many gardeners shift focus to establishing perennial crops, soil amendment, and planning shade gardens.
- How do I address Phoenix's alkaline soil?
Phoenix soils typically run pH 7.5-8.0 due to mineral-rich caliche subsoil. Amend beds with sulfur to lower pH gradually, or build raised beds with imported soil at pH 6.5-7.0. Monitor soil pH annually, especially after water and fertilizer additions.
- Which varieties perform best in Phoenix heat?
Look for tomato and pepper varieties bred for heat tolerance. Black Mission fig and Manzanillo olive are established choices for the Phoenix area. Regional university extensions regularly test and recommend varieties suited to Phoenix's specific climate conditions.
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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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