Local planting guide · Great Plains
zip 77046
Houston is in USDA hardiness zone 9b, with average winter lows of 25°F to 30°F. The local growing season runs roughly 01/30 through 12/28 (~330 days). This zip falls within the Great Plains growing region.
- USDA zone
- 9b 25°F to 30°F
- Last spring frost
- 01/30
- First fall frost
- 12/28
- Growing season
- 330 days
- Compatible crops
- 37
- Growing region
- Great Plains
Right now in Houston
Week 18 priorities
On the docket: transplant out after last frost · direct sow after last frost. See the full calendar →
Gardening in Houston
Houston's zone 9b climate is defined less by cold than by heat and humidity. The last spring frost arrives by January 30, and the first fall frost doesn't return until December 28, creating a 330-day growing season where winter is not the limiting factor. Instead, the challenge is navigating a hot, humid subtropical climate where summer temperatures regularly exceed 95°F and humidity stays high throughout the year. This environment makes Houston ideal for heat-loving subtropicals like figs, Asian persimmons, pomegranates, and jujubes, which struggle in cooler zones but thrive here. Peppers, especially hot varieties, flourish in the extended warmth. However, traditional temperate crops require different timing: tomatoes, for instance, produce best in Houston's cooler seasons (fall, winter, and spring), not summer. The region's year-round growing potential is offset by pressure from heat-driven pests like spider mites and fungal diseases that exploit the humid conditions. For most Houston gardeners, the challenge is not protecting plants from frost but managing summer stress.
Regional context · Great Plains
What the Great Plains brings to Houston
Continental, windy, with severe heat and cold extremes. Cold-hardy fruit and small grains north; long warm season for melons, peppers, and pecans south.
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 Houston
Summer heat is the dominant constraint for most gardeners in Houston. Many vegetable varieties bred for temperate zones simply won't set fruit or produce quality yields when temperatures exceed 95°F consistently from June through September. Tomatoes, peppers, and cucurbits often drop flowers in peak summer heat. Humidity creates a second persistent challenge: powdery mildew, black spot, and other fungal diseases spread rapidly in warm, humid conditions, especially in spring and early summer. Spider mites explode in July and August, particularly on stressed plants. A third issue is soil management. Houston's native clay and alkaline soils resist amendment and retain water poorly during dry spells while compacting easily. Raised beds or container growing become necessary for consistent results.
Crops that grow in Houston
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 Houston
Year-view of seed starting, transplanting, planting, pruning, fertilizing, harvest, and pest-watch windows tuned to Houston's local frost dates.
Week ? · loading
This week in Houston, TX (zone 9b)
Quiet week in Houston, TX (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 Houston
Plan tomato plantings for fall and winter harvest rather than summer. Plant transplants in late July or August for a September-through-December harvest, and again in late January or early February for a March-May crop. Summer tomato attempts almost always disappoint due to heat-induced flower drop. Second, space plants wider than textbook recommendations to maximize air movement and reduce fungal disease pressure in Houston's humid environment. Powdery mildew can appear on squash and grapes even in winter if foliage stays wet and air doesn't circulate freely. Third, use your frost-free window strategically: with frost risk essentially zero after early February, start seeds indoors in late January and transplant by mid-February, giving transplants eight months to mature before any real cold risk returns in late December.
Frequently asked questions
- What are the best crops to grow in Houston?
Heat-loving crops dominate: peppers thrive year-round, while figs, pomegranates, jujubes, and Asian persimmons flourish in the warmth. Tomatoes, sweet potatoes, okra, and southern peas do well during their ideal seasons. Fall and winter vegetables like greens, broccoli, and root crops prefer the cooler months (November through March).
- When should I plant tomatoes in Houston?
Tomato success in Houston requires seasonal timing. Plant transplants in late July or early August for a fall harvest (September through November), and again in late January or early February for a spring harvest (March through May). Avoid summer planting; heat causes flower drop and poor fruit set from June through August.
- What's the biggest weather risk for Houston gardeners?
Summer heat, not cold, is the primary threat. Temperatures regularly exceed 95°F from June through August, stopping production in many crops and stressing plants overall. Humidity compounds the problem by driving fungal disease. Freezes are rare enough (last spring frost January 30, first fall frost December 28) that they rarely pose a real threat.
- Can I grow year-round in Houston?
Essentially yes, but with caveats. Peppers and other heat lovers produce year-round. Cool-season crops thrive from November through March. The summer months (June through August) are a gap for many temperate vegetables, though okra, Armenian cucumber, and other heat-loving crops fill part of that space. Succession planting and seasonal crop rotation maximize year-round production.
- Why do my tomatoes fail in summer?
Tomato flowers drop when nighttime temperatures stay above 75°F, which happens June through September in Houston. Even heat-tolerant varieties struggle. This is why fall, winter, and spring tomato plantings succeed while summer attempts almost always disappoint, regardless of variety or care.
- How can I prevent fungal diseases in Houston's humidity?
Space plants further apart than standard spacing to allow air circulation. Water at soil level in early morning, never overhead. Prune out crowded branches. In humid months (spring and summer), watch closely for powdery mildew on squash, grapes, and peppers, and remove infected foliage promptly to prevent spread.
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Frost data: NOAA Climate Normals 1991-2020, station USW00012918. Local microclimates can shift these dates by a week or more.
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