Local planting guide · Great Plains
zip 77240
Houston is in USDA hardiness zone 9b, with average winter lows of 25°F to 30°F. The local growing season runs roughly 02/13 through 12/09 (~300 days). This zip falls within the Great Plains growing region.
- USDA zone
- 9b 25°F to 30°F
- Last spring frost
- 02/13
- First fall frost
- 12/09
- Growing season
- 300 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 classification masks a distinctly subtropical growing environment. With a 300-day frost-free season bracketed by a February 13 last-spring-frost date and a December 9 first-fall-frost date, the calendar constraint is minimal. The dominant pressure is heat and humidity. Summer temperatures regularly exceed 95°F, and the Gulf of Mexico supplies moisture that keeps humidity high from May through September. This combination creates ideal conditions for heat-loving crops (figs, pomegranates, Asian persimmons, and peppers thrive in these conditions), but also drives fungal disease pressure that does not exist in drier zone 9b climates. The winter cold (25 to 30°F lows) is sufficient to provide adequate chill hours for many fruit trees, though marginal for cold-tender varieties. Tomatoes, the summer staple elsewhere, often stop setting fruit during peak heat in July and August, making fall succession plantings and heat-tolerant varieties the practical choice.
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
Three issues consistently frustrate Houston gardeners. First, the February 13 last-frost date is deceptively late; frost in early March can catch early-planted transplants, particularly frost-sensitive annuals like peppers and basil planted too eagerly in late February. Second, the combination of summer heat (95°F+), high humidity, and Gulf moisture creates near-perfect conditions for fungal diseases. Early blight and septoria leaf spot on tomatoes appear by mid-June and accelerate in July; powdery mildew affects squash, beans, and ornamentals by late July. Third, late-summer tropical moisture from June through September brings heavy rains that lead to root rot in poorly drained soil and accelerate fungal growth. Gardeners who ignore the humidity factor and plant as if they were in a drier climate often lose crops to fungal pressure that could have been managed with wider spacing, soil-level irrigation, and resistant varieties.
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
Succession-plant tomatoes in two windows: start transplants in early March (a week or two after the February 13 frost date) for an early-summer crop, then again in late July for a fall harvest that avoids the peak July-August heat when fruit set stops. Between these windows, swap tomatoes for peppers: both are frost-tender, but sweet and hot peppers reliably set fruit through August when tomato pollen becomes sterile. Plant perennials that embrace the heat: figs and pomegranates are regionally iconic, require minimal water once established, fruit reliably in Houston's heat, and tolerate the humidity that stresses many cooler-climate crops.
Frequently asked questions
- What's the best fruit to grow in Houston zone 9b?
Figs and pomegranates thrive in Houston's heat and humidity with minimal intervention. Asian persimmons are also reliable. These crops tolerate the summer heat without fussing and don't require the careful fungal management that tomatoes demand.
- When should I plant tomatoes in Houston?
Plant transplants in early March (by March 5 or so) for an early-summer harvest, then wait until late July to start a fall crop. Peak summer heat (July and August) causes tomatoes to stop setting fruit, making fall the more reliable season for quality production.
- What about the February 13 frost date, is that really when I can plant?
The February 13 date is the average last frost, but frost can occur into early March. Plant frost-tolerant crops (tomatoes, peppers, basil) no earlier than mid-March to reduce frost risk. Tender perennials like figs and pomegranates can go in the ground after mid-March as well.
- Why do my tomatoes fail in summer?
Tomatoes stop setting fruit when nighttime temperatures stay above 75°F (which happens in Houston from July onward). Pollen becomes sterile. Fall crops planted in late July mature in cooler weather and produce reliably through November.
- How do I prevent fungal diseases in Houston's humidity?
Space plants farther apart than standard spacing to improve air circulation. Water at soil level, not overhead, and water early morning so foliage dries fast. Choose disease-resistant varieties. Mulch to prevent soil splash onto leaves.
- Is zone 9b really 10 months of frost-free growing?
Yes. The 300-day frost-free season means gardeners can plant something green from mid-March through November. Winter cool-season crops (leafy greens, brassicas, root crops) actually thrive in Houston's mild winters when summer heat is absent.
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Frost data: NOAA Climate Normals 1991-2020, station USW00012960. Local microclimates can shift these dates by a week or more.
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