Local planting guide · Southwest
zip 85029
Phoenix is in USDA hardiness zone 9b, with average winter lows of 25°F to 30°F. The local growing season runs roughly 01/08 through 12/25 (~354 days). This zip falls within the Southwest growing region.
- USDA zone
- 9b 25°F to 30°F
- Last spring frost
- 01/08
- First fall frost
- 12/25
- Growing season
- 354 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 gardening is defined by two extremes: a nearly year-round growing season with minimal frost risk, and sustained high heat that eclipses most other constraints. With a last spring frost around January 8th and first fall frost not until December 25th, the calendar permits 354 days of potential growth. However, average winter lows in zone 9b stay between 25 and 30°F, and summer highs regularly exceed 110°F. The real limiting factor is heat, not cold. Many crops bred for cooler climates will simply stop producing or decline in quality during Phoenix's intense summer (typically May through September). Figs, pomegranates, jujubes, Asian persimmons, and goji berries thrive in this heat and drought, whereas stone fruits and tender vegetables struggle once temperatures exceed 100°F for extended periods. Soil in the Phoenix area tends toward alkalinity, which can lock up essential nutrients and compounds the challenge of sustained irrigation with hard water. Success in Phoenix hinges on crop selection for heat tolerance, intelligent spacing to avoid shade competition, and a clear irrigation strategy rather than on frost protection.
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
The most common defeat for Phoenix gardeners is inadequate shade or heat protection during mid-summer (June through August), when daytime highs exceed 110°F for weeks at a time. Tomatoes, peppers, and stone fruits stop setting fruit, develop sunscald on exposed sides, or drop foliage entirely without overhead shade or strategic eastern exposure. A second major issue is late spring frost (January 8th) catching early bloomers. Deciduous fruit trees and tender perennials that break dormancy in December or early January often lose emerging leaves or flowers to frost in early January. Third, soil alkalinity and hard water create chronic nutrient deficiencies, especially in iron, zinc, and manganese, which manifest as chlorosis (pale or yellowing foliage) on susceptible crops. Addressing alkalinity requires heavy sulfur or organic-matter amendments at planting and regular soil testing.
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 frost-sensitive annuals (tomatoes, peppers, eggplant) in mid-February, after the January 8th frost, rather than in early winter. This ensures transplants establish after frost risk closes and avoid the stress of repeated frost exposure on young plants. Second, install 30 to 50 percent shade cloth by late April to protect spring plantings of peppers, tomatoes, and squash from sunscald and heat stress. Orient plantings with afternoon shade from deciduous trees or structures; even filtered shade dramatically extends the productive window into summer. Third, apply sulfur or iron chelate amendments before planting and retest soil pH annually. Most vegetables and fruits prefer pH 6.0 to 7.0, but Phoenix soils often run 7.5 to 8.5 without amendment. Starting with corrected soil chemistry saves years of fighting nutrient lockup.
Frequently asked questions
- What fruits grow best in Phoenix?
Figs, pomegranates, jujubes, Asian persimmons, and goji berries are excellent choices for zone 9b Phoenix heat and drought. These crops evolved in climates with intense summer sun and minimal water, so they rarely require shade cloth or intensive irrigation once established. Avoid tender stone fruits like peaches and plums, which struggle with late January frost and heat-induced fruit drop.
- When should I plant tomatoes and peppers in Phoenix?
Plant tomato and pepper transplants in mid-February after the January 8th frost passes. Planting earlier risks frost damage to seedlings. Plan a second planting in late July or August for fall harvest, since summer heat (110°F+) stops most varieties from flowering reliably. Fall-planted crops produce through December before the first frost arrives on December 25th.
- How do I prevent sunscald and heat damage to fruit?
Install 30 to 50 percent shade cloth by late April and maintain it through September. Shade reduces surface temperature on fruit by 10 to 20°F and prevents the bleaching and cracking caused by intense UV exposure. Drip irrigation under the canopy also reduces plant stress compared to overhead watering, which can evaporate before reaching roots in Phoenix's low humidity.
- What's the biggest frost risk in Phoenix?
Late spring frost on January 8th catches many gardeners off guard. Deciduous trees that break bud in December (triggered by short, mild days) often lose flowers or new foliage to frost in early January. Plan tender perennials and new growth with January frost in mind; delay dormancy-break by keeping plants in cooler microclimates or delaying winter pruning until mid-January.
- How do I fix my alkaline soil?
Apply sulfur at planting and annually thereafter to lower pH. Most vegetables need pH 6.0 to 7.0; Phoenix soils often run 7.5 to 8.5. Work in compost and aged manure to buffer alkalinity. Have soil tested every 1 to 2 years; organic matter and sulfur amendment are ongoing maintenance in alkaline climates, not one-time fixes.
- Can I grow in winter in Phoenix?
Yes, but with caution. Winter frost risk closes January 8th, so any tender crops planted before mid-January need frost protection. Leafy greens, root crops, and brassicas can grow productively November through March if frost-protected after January 8th. The long, mild winter (December 25th frost) is ideal for cool-season crops once they escape the late January frost window.
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Frost data: NOAA Climate Normals 1991-2020, station USW00003184. Local microclimates can shift these dates by a week or more.
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