Local planting guide · Southwest
zip 85039
Phoenix is in USDA hardiness zone 10a, with average winter lows of 30°F to 35°F. The local growing season runs roughly 01/05 through 01/03 (~365 days). This zip falls within the Southwest growing region.
- USDA zone
- 10a 30°F to 35°F
- Last spring frost
- 01/05
- First fall frost
- 01/03
- Growing season
- 365 days
- Compatible crops
- 28
- 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 year-round frost-free growing season (essentially 365 days, with the last spring frost around January 5 and the first fall frost in early January) is actually a two-edged sword. Yes, something can grow almost every month. But the real constraint is intense desert heat. Temperatures regularly exceed 110°F from June through August, killing or severely stressing crops that most zone 10a gardeners rely on elsewhere. Fig, pomegranate, goji berry, and Asian persimmon thrive in Phoenix's heat when other zone 10a regions struggle. Summer tomatoes are nearly impossible without massive afternoon shade; spring and fall varieties are where the real opportunity lies. The dominant challenge is not frost but rather the brutal June-August window, when heat damage and spider mite explosions affect nearly every crop. Soil pH tends alkaline in Phoenix's mineral-rich desert soils, which crops like pomegranate tolerate well; others need amendment. Water is perpetually scarce. Gardeners who stop fighting the heat and instead select heat-loving varieties and adjust timing to spring and fall actually succeed at yields that zone 10a regions with milder summers cannot match.
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 10a, drawn from the broader USDA zone profile.
- ▸ No chilling for traditional temperate fruit
- ▸ Hurricane exposure
- ▸ Heat-tolerant cultivars only
What defeats new gardeners in Phoenix
Phoenix's defining constraint is not frost but extreme desert heat. Summer temperatures above 110°F kill young transplants, scald fruit (especially tomatoes), cause severe sunburn on exposed bark, and trigger population explosions of spider mites and whiteflies. The alkaline, low-organic-matter soil is the second challenge. Pomegranate tolerates this well; peppers and tomatoes need sulfur amendments to reach optimal pH. Third, irrigation is unreliable and expensive. Many gardeners on municipal water face rationing in summer, exactly when irrigation demand peaks. The January 5 last-spring-frost date creates a false sense of security; gardeners mistakenly assume they can grow anything that tolerates heat, then lose crops to spider mites or fruit scald instead.
Crops that grow in Phoenix
28 crops from our catalog match zone 10a, grouped by type.
Tree fruit
12 crops
zone 10a Fig
Ficus carica
zones 7a–10b
zone 10a Asian Persimmon
Diospyros kaki
zones 7a–10a
zone 10a Pomegranate
Punica granatum
zones 7b–10a
zone 10a Lemon
Citrus limon
zones 9a–11b
zone 10a Orange
Citrus sinensis
zones 9a–11b
zone 10a Lime
Citrus aurantiifolia
zones 9b–11b
zone 10a Grapefruit
Citrus paradisi
zones 9a–11b
zone 10a Avocado
Persea americana
zones 9b–11b
Berries
3 crops
Nuts
1 crop
Vegetables
10 crops
zone 10a Tomato
Solanum lycopersicum
zones 3a–10b
zone 10a Sweet Pepper
Capsicum annuum
zones 4a–10b
zone 10a Hot Pepper
Capsicum species
zones 4a–10b
zone 10a Eggplant
Solanum melongena
zones 5a–10b
zone 10a Cucumber
Cucumis sativus
zones 3b–10a
zone 10a Summer Squash
Cucurbita pepo
zones 3b–10a
zone 10a Melon
Cucumis melo
zones 5a–10a
zone 10a Watermelon
Citrullus lanatus
zones 5b–10a
Herbs
2 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 10a)
Quiet week in Phoenix, AZ (zone 10a). this week is a good time to step back and plan ahead.
Nothing critical on the calendar this week.
147 bars · 28 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 10a
Ranked by how many crops in your zone they affect. Click through for IPM controls and signs to watch for.
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.
Meloidogyne species
Microscopic soil-dwelling worm that forms galls on roots, reducing vigor and yield.
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.
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.
Tetranychus urticae
Tiny mite that feeds on leaf undersides, causing stippling and webbing during hot dry weather.
Ceratitis capitata
Quarantine pest in many regions. Adult females puncture ripening fruit to lay eggs; larvae tunnel through the flesh, causing premature drop and rot.
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.
Top diseases for zone 10a
Ranked by how many crops in your zone they affect. Click through for symptoms, controls, and resistant varieties.
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.
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.
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.
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.
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.
Colletotrichum gloeosporioides
Most damaging mango disease worldwide. Fungal spores infect blossoms and developing fruit during humid weather, producing black sunken lesions that expand on ripening fruit.
Multiple species (Erysiphales)
Surface-feeding fungal disease producing white powdery growth on leaves and stems. Reduces yield by stealing photosynthate and accelerating senescence.
Companion planting suggestions
Beneficial pairings drawn from companion data, filtered to crops that grow in zone 10a.
- 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.
- Okra + Hot Pepper
Both heat-loving warm-season crops with similar water and fertility needs. Hot pepper at okra's base benefits from the slight afternoon shade in extreme summer heat.
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, adjust your planting calendar to Phoenix's true seasons: spring (December through February), monsoon/early summer (June through July), and fall (August through November). Winter growth is slower; treat January as your practical spring frost date and plan frost-sensitive crops accordingly. Second, fig and pomegranate are nearly foolproof in Phoenix's heat and alkaline soil; Asian persimmon performs well in warm microclimates. Tomatoes succeed only with 50% shade cloth from April through September and cultivar selection (cherry varieties outlast slicing types in heat). Third, invest in drip irrigation and mulch heavily. Afternoon shade, consistent irrigation, and 4 inches of wood-chip mulch together prevent the heat damage and water stress that kill more Phoenix crops than any other cause.
Frequently asked questions
- What are the best crops to grow in Phoenix?
Fig, pomegranate, Asian persimmon, and goji berry thrive in Phoenix's desert heat and alkaline soil. Sweet peppers, hot peppers, eggplant, and tomatoes (with afternoon shade in summer) also succeed, especially in spring and fall. Asian persimmon is more marginal but performs well in warm, south-facing microclimates.
- When should I plant tomatoes in Phoenix?
Plant tomato transplants in late September or October for a fall/winter crop, or in late January/early February for spring harvest. Avoid summer planting (April through September); temperatures above 110°F, spider mites, and intense solar radiation kill vines and scald fruit. Cherry varieties survive heat better than slicing types. Spring plantings need 50% shade cloth April through September.
- What's the biggest weather threat to Phoenix gardens?
Extreme summer heat, not frost. Temperatures above 110°F (common June through August) cause transplant death, fruit sunscald, and massive spider mite outbreaks. Spider mites are the single most destructive pest for Phoenix gardeners. Occasional cold snaps in late winter can briefly stress young plants, but frost is rare.
- Is frost a real concern in Phoenix?
No. The last spring frost typically arrives January 5, and the first fall frost doesn't occur until early January, creating an essentially frost-free, 365-day growing season. This is actually a disadvantage for gardeners unfamiliar with desert conditions; they plant tender crops expecting year-round harvest and lose them to heat instead of frost.
- Why is my Phoenix soil so alkaline?
Desert soils naturally accumulate minerals and have high pH (often 7.5 to 8.5). Pomegranate tolerates this well. Peppers and tomatoes prefer slightly acidic pH and benefit from sulfur amendments applied in fall; allow time for microbial conversion before spring planting.
- Can I garden year-round in Phoenix?
Yes, but productivity varies sharply by season. Winter and spring are ideal for most crops. The summer monsoon (June-July) is too hot for many varieties. Fall (August-November) is productive again. Year-round gardening requires heat-tolerant varieties like figs, pomegranates, and peppers, plus shade strategies for cool-season crops.
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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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