Local planting guide · Southwest
zip 85070
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's gardening climate inverts the conventional pattern. With a virtually frost-free year, frost risk confined to the brief window around early January, with the last frost by January 5, heat rather than cold defines what grows and when. Summer temperatures regularly exceed 110°F, rendering June through September dormant for most gardeners. The productive season runs October through May, when temperatures drop to the 65 to 85°F range ideal for vegetables and deciduous fruit trees. This 365-day growing season is an advantage, not a constraint, but only if crops are selected and timed to escape peak heat. Figs, pomegranates, jujubes, and Asian persimmons thrive in the zone 9b climate. Cool-season vegetables like tomatoes and peppers produce prolifically when planted in late summer for fall and winter harvest, not spring.
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 dominant constraint. From June through August, most familiar vegetable crops fail to set fruit or develop bitter, unmarketable foliage. Peppers often drop flowers when nighttime temperatures stay above 75°F; tomatoes stop setting fruit above 85°F day and night. The second challenge is water management. Phoenix's desert climate alternates between droughts demanding frequent, deep irrigation and monsoonal downpours that can waterlog poor-draining soil and trigger fungal diseases like root rot and powdery mildew. The third is sunscald on tree fruit. Even heat-adapted varieties like pomegranate or fig can split, sunburn, or stop producing under prolonged 115°F+ exposure and full afternoon sun.
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
Shift your planting calendar six months ahead of traditional schedules. Tomatoes, peppers, and warm-season vegetables should be sown or transplanted in August and September so they establish and produce through the mild winter before summer heat arrives. This inverted timing works because frost threat ends by January 5, making fall plantings safe and allowing 150+ frost-free days of production. Second, provide afternoon shade during peak heat (May through September). A 30% shade cloth or existing deciduous trees can prevent fruit loss and allow perennial crops like fig and Asian persimmon to remain productive. Third, mulch heavily (3 to 4 inches) and water deeply but infrequently to build deep root systems that tap stable soil moisture and reduce irrigation frequency.
Frequently asked questions
- What vegetables should I grow in Phoenix?
Tomatoes, peppers, leafy greens, root crops, and brassicas thrive from late September through April. Plant these in August and September for fall and winter harvest. In summer, focus on heat-extreme crops like Armenian cucumber or yard-long beans. Spring plantings fail as temperatures approach 100°F by May.
- When should I plant tomatoes in Phoenix?
Plant tomato transplants in August and early September for harvest from November through May. Spring plantings (March-April) will stop setting fruit by June as temperatures exceed 90°F. Phoenix's long, mild winter actually delivers more total tomato production than cooler climates, just on a reversed schedule.
- Is frost a real concern in Phoenix?
Frost risk is minimal and restricted to early January. With frost-free conditions from January 5 through the following January 3, you'll rarely lose established plants to cold. Focus instead on heat protection during summer and selecting heat-tolerant varieties for perennial fruit trees.
- Which fruit trees grow best in Phoenix?
Fig, pomegranate, Asian persimmon, jujube, and goji berry are well-suited to zone 9b's low winter lows (25 to 30°F) and intense heat. These require minimal chill hours and thrive in direct sun. Provide afternoon shade and deep mulch in summer to prevent sunscald and water stress.
- How much water do plants need in Phoenix?
Water deeply but infrequently to encourage deep root systems. Established trees and perennials typically need deep watering once or twice weekly in summer, less in winter. Heavy mulching (3 to 4 inches) reduces irrigation needs by 30 to 50% and stabilizes soil temperature.
- What's the most common mistake Phoenix gardeners make?
Following a spring planting calendar and expecting summer production. Phoenix's heat makes May through September nearly unproductive. Successful gardeners flip the calendar to fall and winter planting and harvest, capitalizing on the nearly year-round frost-free season.
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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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