Houston, TX

Houston sits in zone 9b with winter lows of 25-30°F and an exceptionally long 300-day growing season. The last spring frost typically arrives February 13, and the first fall frost doesn't arrive until December 9. This extended window is Houston's greatest asset: gardeners can produce crops from early winter through late fall with minimal cold pressure.

The dominant constraint is summer heat and humidity. Temperatures regularly exceed 95°F from June through September, paired with 80%+ humidity that creates ideal conditions for fungal diseases and pest activity. Many standard varieties that perform elsewhere struggle in Houston's heat. Southern-adapted cultivars and heat-tolerant species outperform northern varieties significantly.

Figs, Asian persimmons, pomegranates, jujubes, and goji berries thrive in Houston's warmth where cooler zones cannot grow them. Tomatoes and peppers produce heavily but require variety selection: cherry and heat-loving types outperform many heirloom slicers that sunscald above 95°F.

Soils are often alkaline or neutral with poor drainage in clay-heavy areas. Amending with sulfur to lower pH and improving drainage through mulch or raised beds addresses both issues. Fungal disease pressure is significantly higher than in drier or cooler zones, requiring vigilant variety selection and crop rotation.

Freezes strong enough to damage tender perennials are rare but not impossible. Marginal perennials benefit from frost cloth protection on those rare February nights when temperatures approach freezing.

Southern leaf blight and other fungal diseases thrive in Houston's humidity, particularly on tomatoes and peppers in July and August. Foliar fungicides help, but variety selection and crop rotation prevent the problem more effectively.

Sunscald on tomatoes is nearly universal in Houston when standard slicing varieties are grown. Temperatures above 95°F cause white patches and pitting on fruit. Cherry and heat-loving varieties like 'Phoenix' or 'Heatwave' avoid the problem; heirloom slicers require shade cloth during peak summer heat.

The rare late freeze in late February or early March can destroy tender perennial shoots like fig and pomegranate that begin growth after the mild winter. A light frost cloth protects against the occasional hard freeze dipping below 30°F.

Succession plant tomatoes and peppers in two windows. Plant transplants in late January for early harvest before June heat, then again in late July or August for a fall crop that avoids mid-summer fungal pressure. This captures spring production and fall production when heat moderates in October-November.

Select heat-tolerant and disease-resistant varieties from the start. Standard northern varieties sunscald and succumb to fungal disease in Houston. Seek varieties rated for zone 9b heat: 'Phoenix' or 'Heatwave' tomatoes, 'Mohawk' peppers, figs suited to heat. Nurseries and extension publications rarely steer gardeners wrong on heat-adapted picks for Houston.

Use frost cloth for tender perennials in January and February. Even though the last frost is February 13, occasional February cold snaps dip to the upper 20s°F. Lightweight frost cloth draped over figs, pomegranates, and other marginal perennials provides protection when needed.