Local planting guide · Southwest
zip 85017
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 presents a gardening paradox: the calendar shows USDA zone 9b with winter lows of 25-30°F, yet frost arrives around January 5 and departs by January 3, creating a 365-day growing season. The real constraint is heat and water availability, not cold. From May through September, temperatures regularly exceed 110°F, with humidity typically below 20 percent. Crops that flourish here are those evolved for arid heat: figs, Asian persimmons, pomegranates, jujubes, and goji berries thrive in Phoenix when planted in well-draining soil and given minimal supplemental water once established. Traditional spring gardening fails. Instead, Phoenix runs on a split calendar: cool-season crops (October through April) include tomatoes, peppers, and leafy greens, while the May-to-September window demands either heat-adapted annuals (Armenian cucumber, yard-long beans) or dormancy. The monsoon season (July-September) brings brief rainfall but intense sun and heat. Success in Phoenix gardening depends less on frost protection and more on matching crops to the season and managing water and shade strategically.
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 kills or stresses most traditional vegetables from June through August. Tomatoes planted in spring bolt or drop fruit once temperatures exceed 95°F; peppers hang on longer but still struggle. Second, water restrictions during peak cooling season (June-August) constrain supplemental irrigation precisely when landscape demand is greatest. Caliche layers (calcium carbonate hardpan) are common in Phoenix soils, restricting root depth and drainage; breaking through or amending around caliche is often necessary before planting fruit trees. Third, low humidity and intense UV exposure sunscald even heat-tolerant crops; afternoon shade cloth becomes essential for summer vegetables. Powdery mildew thrives in the temperature fluctuations and low humidity of spring (March-April) and fall (October-November), making disease-resistant varieties non-negotiable for melons and squash.
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
Start tomatoes and peppers indoors in late January for transplant in late February or early March, aiming to harvest before temperatures exceed 95°F consistently (usually late May). Plan a second crop from seed in late July for November-December harvest. Use shade cloth (30 to 50 percent density) from May through September on any vegetable worth keeping productive; afternoon shade can be the difference between viability and complete failure. Plant evergreen fruit trees (figs, pomegranates, jujubes) from October through February while soil is cool and water demand is low, giving roots time to establish before summer arrives.
Frequently asked questions
- When do I plant tomatoes in Phoenix?
Start seeds indoors in late January for transplant in late February or early March. Harvest before temperatures exceed 95°F consistently (usually late May). For a fall crop, direct seed in late July and expect harvest from October through December. Traditional spring-to-summer tomato growing doesn't work in Phoenix; plan for two shorter seasons instead.
- Do I really need to worry about frost in Phoenix?
No. With a last spring frost around January 5 and first fall frost around January 3, frost is essentially a non-issue. The real concern is extreme heat from May through September. Focus frost-protection efforts on container plants and tender perennials only during the rare dip below 30°F in December.
- Can I garden year-round in Phoenix?
Yes, but not with the same crops. October through April is prime for cool-season crops, tomatoes, peppers, and leafy greens. May through September demands heat-adapted annuals or dormancy for most vegetables. Evergreen fruit trees like figs and pomegranates can grow actively year-round if watered appropriately.
- What fruit trees grow best in Phoenix?
Figs, Asian persimmons, pomegranates, jujubes, and goji berries are well-suited to Phoenix's heat and low humidity. These require minimal water once established and tolerate intense summer sun. Apples and pears need more chill hours than Phoenix typically provides, making them poor choices.
- How do I keep vegetables alive during summer heat?
Shade cloth (30 to 50 percent density) is essential from May through September. Morning sun is tolerated; afternoon shade is critical. Choose heat-tolerant varieties like Armenian cucumber and yard-long beans. Water deeply and infrequently to encourage deep rooting and minimize salt accumulation in arid soil.
- What's the biggest weather risk in Phoenix gardening?
Extreme summer heat combined with water restrictions. June through August, temperatures exceed 110°F regularly while municipal water limits constrain irrigation. Even drought-tolerant crops need careful watering during establishment. Mitigate this by establishing perennial fruit trees in cool months and timing annuals to avoid the worst heat.
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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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