Local planting guide · California
zip 94522
Concord is in USDA hardiness zone 9b, with average winter lows of 25°F to 30°F. The local growing season runs roughly 01/09 through 12/14 (~343 days). This zip falls within the California growing region.
- USDA zone
- 9b 25°F to 30°F
- Last spring frost
- 01/09
- First fall frost
- 12/14
- Growing season
- 343 days
- Compatible crops
- 37
- Growing region
- California
Right now in Concord
Week 18 priorities
On the docket: transplant out after last frost · direct sow after last frost. See the full calendar →
Gardening in Concord
Concord sits in USDA zone 9b with winter lows between 25 and 30°F, but the key factor is the extended growing season: 343 days of frost-free weather running from January 9 through December 14. This window makes Concord exceptionally well-suited to both warm-season crops (figs, pomegranates, Asian persimmons, jujubes) and cool-season vegetables in succession. The mild winters eliminate hard-freeze risk that constrains fruit production in lower zones, yet provide sufficient dormancy for stone fruits and tree fruits. Summer heat can peak sharply inland from the Bay, though marine air moderates afternoon temperatures most days. Frost arrives primarily December through early January, rarely persisting long or dropping below the zone's minimum. This climate supports heat-loving crops nearly year-round while maintaining enough winter chill for standard temperate fruit production without extensive winter protection.
Regional context · California
What the California brings to Concord
From cool foggy coast to hot Central Valley to mountain to desert. Mediterranean climate dominates: wet winters, dry summers. The most productive agricultural state in the country, with reach into citrus and olives that exceed the rest 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 Concord
Despite the long season, Concord gardens encounter recurring obstacles. First, December and early January frost events, though typically brief, can damage tender new growth on frost-sensitive crops like young citrus and avocados. This risk window runs December 14 through January 9, threatening transplants and newly emerged growth on tender perennials. Second, summer heat drives rapid water loss and stresses plants preferring cooler conditions; leafy greens bolt quickly under peak temperatures, shortening productive windows. Third, the extended growing season extends pest and disease windows throughout the year. Spider mites and powdery mildew persist from spring into fall without diligent management, requiring attention in both shoulder seasons to prevent population carryover.
Crops that grow in Concord
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 Concord
Year-view of seed starting, transplanting, planting, pruning, fertilizing, harvest, and pest-watch windows tuned to Concord's local frost dates.
Week ? · loading
This week in Concord, CA (zone 9b)
Quiet week in Concord, CA (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 Concord
Start warm-season crops (tomatoes, peppers, squash) in late February or early March to establish before June and July heat, then succession-plant cool-season crops (lettuce, greens, brassicas) in late August for a robust fall and winter harvest through December. Use frost cloth or cold frames on December and January nights when temperatures dip below freezing for frost-sensitive perennials; most established fruit trees handle Concord's winter minimums without protection. Mulch heavily around root zones to moderate summer soil temperature and reduce watering frequency during peak heat, particularly for newly planted trees; this simple practice builds resilience during the driest months.
Frequently asked questions
- What are the most reliable crops to grow in Concord?
Figs, Asian persimmons, pomegranates, and jujubes thrive in the heat and mild winters. Tomatoes and peppers perform exceptionally well in the extended frost-free season. Deciduous stone fruits (peaches, plums) and apples are reliable with dormancy satisfied by Concord winters.
- When should I plant tomatoes in Concord?
Transplant in late February or early March to establish before peak summer heat and allow a full harvest window before December frost risk returns. A second planting in July supports a late-fall crop through December.
- What's the frost risk window for Concord?
Frost occurs from December 14 through January 9, running roughly 26 days. Established, cold-hardy fruit trees withstand this window. Tender crops, young transplants, and frost-sensitive perennials benefit from frost cloth protection on freezing nights.
- Can I grow crops year-round in Concord?
Effectively, yes. The frost-free period from January 9 through December 14 supports continuous planting. Cool-season crops thrive in winter and spring; warm-season crops dominate summer. Succession planting extends harvests further across the calendar.
- How do I manage summer water needs?
Mulch root zones deeply to insulate soil and reduce evaporation. Group plants by water need and consider drip irrigation on timers for consistent delivery. Morning watering encourages deeper roots and reduces disease pressure versus evening watering.
- Do I need to amend the soil?
Most vegetables and fruit trees grow well in Concord's soils without amendment. If you want blueberries or other acid-preferring plants, test your soil first; if neutral or alkaline, add sulfur or acidic mulch around the planting zone.
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Frost data: NOAA Climate Normals 1991-2020, station USW00023254. Local microclimates can shift these dates by a week or more.
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