Local planting guide · Great Plains
zip 77018
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 zone 9b has a 300-day growing season (among the longest in the continental US). The dominant constraint is not frost, but summer heat and humidity. February 13 is the median last spring frost, which is late enough to catch unprepared plantings of warm-season crops. December 9 marks the first fall frost, giving a tight window for fall-planted crops.
The heat and humidity create favorable conditions for certain crops (tomatoes, peppers, figs, jujubes) while creating challenges for others. The long season enables year-round gardening if humidity and heat are managed. Many gardeners in this zone attempt spring crops (February plantings) and then pivot to summer heat-tolerant crops (July to October second plantings). Winter is mild but not freezing.
The main gardening rhythm is inverted from northern zones: the stressful months are June through September (peak heat and humidity), not January through March. Citrus, figs, pomegranates, and jujubes thrive. Cool-season crops (brassicas, leafy greens, root crops) succeed only in the fall, winter, and early spring windows. Soil tends to be clay-heavy and acidic in the Houston area, which affects crop selection and amendment needs.
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
The three biggest challenges: Late spring frost can devastate warm-season plantings in February. A freeze event in February can kill newly emerged tomato seedlings or fig flower buds just as growth accelerates. Summer humidity (May through September) creates ideal conditions for fungal diseases like early blight on tomatoes, anthracnose on cucurbits, and fire blight on pears and apples. Cultivar selection and air circulation are critical.
Summer heat itself (July through September regularly exceeding 95°F) stresses cool-season crops planted too early in fall (before late August), slows pollination in peppers and tomatoes, and increases irrigation demands during dry spells. Many gardeners in zone 9b overestimate how early they can plant warm-season crops in spring because the zone definition is based on the coldest winter temperature, not spring frost patterns. Houston's last frost date (February 13) is deceptively late.
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
Start warm-season crops after mid-February. With a median last frost date of February 13, tomatoes and peppers planted or transplanted before mid-March risk frost damage. Direct-seed warm crops after February 20 for safety. Fall tomatoes planted in early August will mature before the December 9 first frost, often delivering better yields than spring plantings because disease pressure drops in fall.
Prioritize disease-resistant varieties. The humidity from May through September is unrelenting. Select tomato varieties rated resistant to early blight (EB) and fusarium wilt. For peppers and cucurbits, anthracnose resistance matters. Disease codes on seed packets indicate resistance ratings.
Plant fall crops heavily. The August through November window is prime gardening season in Houston. Tomatoes, peppers, brassicas, and root crops thrive. Many gardeners get better yields from fall plantings than spring plantings because heat and disease pressure are lower by October.
Frequently asked questions
- What are the best fruit trees for zone 9b in Houston?
Figs, Asian persimmons, pomegranates, jujubes, and citrus (with frost protection in marginal years) all thrive. Apples and pears are possible but demand more disease management due to humidity.
- When should I plant tomatoes for a spring harvest in Houston?
Transplant tomato seedlings after February 20 to avoid frost damage. For a more reliable harvest, plant tomatoes in early August for a fall crop, which avoids peak summer heat and humidity.
- What's the biggest weather risk for gardeners in Houston?
Late spring freezes (February to early March) can kill newly planted warm-season crops or flower buds on frost-sensitive trees. Monitor forecasts closely from mid-February through mid-March and be prepared to cover young plants.
- Can I grow cool-season crops in Houston?
Yes, but only in fall, winter, and early spring. Plant brassicas, lettuce, and root crops in late August through October for harvest in November through January. Spring plantings made before March rarely succeed because heat arrives by April.
- Why is humidity such a big problem here?
High humidity (typical May through September) creates ideal conditions for fungal diseases like early blight on tomatoes and anthracnose on cucurbits. Spacing plants for airflow and selecting resistant varieties are essential.
- What about peppers in Houston?
Sweet and hot peppers love heat but can drop flowers during peak summer (July-August). Plant in spring (after February 20) for early summer production, then rely on fall plantings (early August) for the main pepper crop when temperatures moderate in October-November.
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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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