Local planting guide · Southwest
zip 85054
Phoenix is in USDA hardiness zone 9b, with average winter lows of 25°F to 30°F. The local growing season runs roughly 01/06 through 12/26 (~353 days). This zip falls within the Southwest growing region.
- USDA zone
- 9b 25°F to 30°F
- Last spring frost
- 01/06
- First fall frost
- 12/26
- Growing season
- 353 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 hot end of zone 9b, where the dominant constraint is not winter cold but summer heat. The zone's temperature minimum is 25 to 30 degrees Fahrenheit, reached on average by January 6. The first fall frost does not arrive until December 26, creating a growing season of 353 days, nearly a full year without lethal freezes. This extended frost-free window is deceptive. While it permits crops like figs, pomegranates, jujubes, and Asian persimmons to fruit heavily, the summer heat becomes the limiting factor for most temperate crops. June through September temperatures routinely exceed 110 degrees Fahrenheit. Tomatoes, sweet peppers, and hot peppers produce through spring and fall, but summer growth slows or stops during peak heat. The dry desert climate also means irrigation is non-optional; rainfall is sparse, and soil pH tends toward alkalinity. Home gardeners who thrive in Phoenix work with the season's extreme halves: a mild winter that allows year-round cool-season cultivation, and a brutal summer that makes heat tolerance the primary variety-selection criterion for warm-season crops.
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 late spring frost date (January 6) catches many home gardeners off-guard, especially early-blooming stone fruits and tender perennials that break dormancy in a mild December or early January. A hard freeze after a warm spell in late December can wipe out a full year's production on peach or apricot. Summer heat above 110 degrees causes fruit scald on exposed fruit, particularly common on peaches and apples grown without afternoon shade cloth. Water access or cost can be prohibitive in an arid climate; drought-tolerant crops like jujubes and pomegranates succeed where water-hungry tomatoes fail without irrigation investment. Alkaline soil is endemic to Phoenix; many acid-loving crops struggle unless soil is heavily amended.
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, use the late spring frost date (January 6) to time heat-tender perennial plantings; delay planting tender herbs and warm-season vines until after mid-January to avoid loss to a cold snap. Second, choose heat-tolerant varieties for summer crops: cherry tomatoes tolerate heat better than beefsteaks, and Asian eggplants outperform Italian types in peak summer. Consider shade cloth (30 to 50 percent) over tomatoes and peppers from June through August; it cuts fruit quality risk from heat scald and permits longer production into late summer. Third, invest in drip irrigation and deep mulch (3 to 4 inches of wood chips); the desert's low humidity means surface-watered soil dries within hours, and efficient irrigation makes the difference between thriving and merely surviving.
Frequently asked questions
- What are the best fruit trees for Phoenix zone 9b?
Figs, pomegranates, jujubes, and Asian persimmons thrive in Phoenix's heat and long season. Peaches and apricots work but require shade cloth during intense summer sun. High-chill apples and temperate cherries need 800 or more chill hours; Phoenix averages only 200 to 300, making these varieties unreliable.
- When should tomatoes be planted in Phoenix?
Phoenix tomatoes are a two-season crop. Fall planting (late August to October) produces through the mild winter and into spring. Spring planting (late February to early March) provides April and May production, with heat-induced slowdown from June to August unless shade cloth is used.
- What's the biggest weather risk in Phoenix?
Late spring freezes after warm spells pose the greatest risk. The last average frost date is January 6, but Phoenix occasionally records freezes into late February following a warm January. Early-blooming trees (peaches, apricots) often lose entire crops. Freeze-tolerant varieties and protection readiness in February and March are essential.
- Can anything be grown during Phoenix summers?
Heat-loving crops like okra, yard-long beans, gourds, and Armenian cucumber produce throughout summer. Shade cloth (30 to 50 percent) over peppers and tomatoes permits continued production into early summer and resumes in late August. Fruit trees remain productive, though growth slows.
- Is Phoenix soil suitable for vegetable gardening?
Phoenix soil is typically alkaline (pH 7.5 to 8.5), locking up iron and other micronutrients. Most vegetables prefer pH 6.0 to 7.0. Amending planting beds with sulfur and compost helps; native Mediterranean plants like pomegranate and fig tolerate alkaline soil without amendment.
- How long is the cool-season growing window in Phoenix?
Phoenix's mild winter extends cool-season cultivation from November through March, with hardy crops producing through mid-May and resuming in late July or August. The first frost does not arrive until December 26, extending the fall season unusually long. Leafy greens planted in early September provide production through March.
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Frost data: NOAA Climate Normals 1991-2020, station USW00003192. Local microclimates can shift these dates by a week or more.
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