Local planting guide · California
zip 91102
Pasadena is in USDA hardiness zone 10b, with average winter lows of 35°F to 40°F. The local growing season runs roughly 12/31 through 12/28 (~365 days). This zip falls within the California growing region.
- USDA zone
- 10b 35°F to 40°F
- Last spring frost
- 12/31
- First fall frost
- 12/28
- Growing season
- 365 days
- Compatible crops
- 23
- Growing region
- California
Right now in Pasadena
Week 18 priorities
On the docket: transplant out after last frost · direct sow after last frost. See the full calendar →
Gardening in Pasadena
Pasadena's gardening calendar runs year-round with minimal frost risk. With a last potential spring frost around December 31 and a first fall frost near December 28, frost protection is rarely needed except in exceptional circumstances. This essentially frost-free climate enables a 365-day growing season where many crops thrive with minimal winter dormancy. The dominant constraint is not cold but summer heat, with afternoon temperatures routinely exceeding 95°F and sometimes reaching 105°F or higher. The crops well-suited to Pasadena include figs, tomatoes, peppers, eggplants, sweet potatoes, basil, and rosemary, reflecting heat-loving plants adapted to subtropical conditions. The extended growing season makes succession planting of warm-season crops particularly valuable. However, the lack of winter cold eliminates the ability to grow traditional high-chill apple and stone fruit varieties. Water management and heat tolerance are the defining gardening challenges in this zone.
Regional context · California
What the California brings to Pasadena
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 10b, drawn from the broader USDA zone profile.
- ▸ No winter chill
- ▸ Tropical pest and disease pressure
- ▸ Saltwater intrusion in coastal soils
What defeats new gardeners in Pasadena
Summer heat presents the most consistent obstacle for Pasadena gardeners. Tomatoes, peppers, and eggplants often drop flowers or fruit when daytime temperatures exceed 95°F for extended periods, particularly in July and August. Sunscald on exposed fruit becomes common without adequate shade. Water management is the second major challenge; Southern California's periodic drought restrictions mean summer irrigation must be efficient and judicious. Powdery mildew thrives in warm, dry conditions and affects a wide range of crops from late spring through early fall. Additionally, the absence of winter dormancy eliminates the ability to grow most traditional apple and stone fruit varieties that require substantial chill hours. Only no-chill or low-chill varieties perform adequately.
Crops that grow in Pasadena
23 crops from our catalog match zone 10b, grouped by type.
Tree fruit
12 crops
zone 10b Fig
Ficus carica
zones 7a–10b
zone 10b Lemon
Citrus limon
zones 9a–11b
zone 10b Orange
Citrus sinensis
zones 9a–11b
zone 10b Lime
Citrus aurantiifolia
zones 9b–11b
zone 10b Grapefruit
Citrus paradisi
zones 9a–11b
zone 10b Mango
Mangifera indica
zones 10b–13b
zone 10b Avocado
Persea americana
zones 9b–11b
zone 10b Banana
Musa acuminata
zones 9b–13b
Berries
2 crops
Nuts
1 crop
Vegetables
6 crops
zone 10b Tomato
Solanum lycopersicum
zones 3a–10b
zone 10b Sweet Pepper
Capsicum annuum
zones 4a–10b
zone 10b Hot Pepper
Capsicum species
zones 4a–10b
zone 10b Eggplant
Solanum melongena
zones 5a–10b
zone 10b Sweet Potato
Ipomoea batatas
zones 6a–10b
zone 10b Okra
Abelmoschus esculentus
zones 6a–10b
Herbs
2 crops
Plan the year
Planting calendar for Pasadena
Year-view of seed starting, transplanting, planting, pruning, fertilizing, harvest, and pest-watch windows tuned to Pasadena's local frost dates.
Week ? · loading
This week in Pasadena, CA (zone 10b)
Quiet week in Pasadena, CA (zone 10b). this week is a good time to step back and plan ahead.
Nothing critical on the calendar this week.
128 bars · 23 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 10b
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.
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.
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 (Aphididae)
Small soft-bodied sap-sucking insects that reproduce explosively in spring. Excrete honeydew that supports sooty mold and attracts ants. Transmit viral diseases.
Meloidogyne species
Microscopic soil-dwelling worm that forms galls on roots, reducing vigor and yield.
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.
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.
Anastrepha suspensa
Tropical fruit fly endemic to Florida and the Caribbean. Less aggressive on commercial citrus than Mediterranean fruit fly, but devastating on guava, carambola, and other thin-skinned tropicals.
Top diseases for zone 10b
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.
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.
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.
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.
Verticillium dahliae
Soil-borne fungal disease similar to fusarium wilt but with broader host range and cooler temperature optimum. Persists in soil for 10+ years.
Candidatus Liberibacter asiaticus
Devastating bacterial disease vectored by the Asian citrus psyllid. Once infected, trees decline progressively over several years and there is no cure. Has destroyed commercial citrus across Florida and threatens production worldwide.
Xanthomonas citri
Bacterial disease producing raised corky lesions on leaves, twigs, and fruit. Spread by wind-driven rain and contaminated tools. Quarantine-regulated in many areas.
Xanthomonas euvesicatoria and X. perforans
Bacterial disease causing leaf spots and fruit blemishes on pepper and tomato. Severe in warm humid weather, transmitted via splashing water and seed.
Companion planting suggestions
Beneficial pairings drawn from companion data, filtered to crops that grow in zone 10b.
- 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 Pasadena
Shade cloth at 30 to 50 percent density protects heat-sensitive crops from late May through mid-September, preventing flower and fruit drop in tomatoes and peppers while maintaining adequate light for growth. Strategic timing of plantings is equally important: tomato and pepper transplants established in early spring (February through March) reach full production before peak summer heat, while succession plantings in late August produce fall and winter crops. The extended growing season also enables a shift in vegetable emphasis toward cool-season crops from October through April, when lettuce, brassicas, root crops, and herbs produce abundantly without heat stress, reducing summer water demands.
Frequently asked questions
- What crops grow best in Pasadena?
Heat-loving crops thrive year-round in zone 10b. Tomatoes, peppers (sweet and hot), eggplants, figs, basil, rosemary, and sweet potatoes excel. Cool-season crops like lettuce, broccoli, cabbage, and root vegetables flourish from October through April. Standard apple and stone fruit varieties require high chill hours and perform poorly; only no-chill or low-chill varieties are suitable.
- When should I plant tomatoes in Pasadena?
Tomato transplants thrive in early spring (February to March) for the main crop, reaching full production before peak summer heat. A second planting in late August provides fall and early winter harvests. Successive plantings staggered 3 to 4 weeks apart support continuous harvests.
- How much of the year is frost-free?
Frost risk is minimal year-round in zone 10b. With a last spring frost around December 31 and a first fall frost near December 28, the growing season is essentially 365 days. Frost protection is rarely needed, though tender transplants in December and January may benefit from brief protection on occasional cold nights.
- How do I manage intense summer heat?
Shade cloth at 30 to 50 percent density is essential from late May through mid-September. Consistent, deep irrigation during heat, increased mulch depth, and heat-tolerant variety selection all reduce stress. Morning watering is more effective than evening irrigation for reducing plant stress.
- What about water restrictions in Pasadena?
Water efficiency is critical given periodic drought restrictions in Southern California. Drip irrigation reduces waste compared to overhead watering. Summer gardens benefit from heat-tolerant, water-efficient crops, while fall and winter vegetable production reduces overall water demand.
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Frost data: NOAA Climate Normals 1991-2020, station USW00023152. Local microclimates can shift these dates by a week or more.
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