Varieties labeled as “heat tolerant” will perform relatively well (compared to other varieties within their crop group) when exposed to hot weather. The Johnny’s Research Team assigns the Heat Tolerant symbol to individual varieties within crop groups that traditionally do not perform well in the heat (as opposed to warm season crops that thrive in the heat); we do this to guide growers to more suitable options. In addition to trialing heat-tolerant versions of cool-weather crops such as broccoli, cauliflower, and lettuce, we also seek out highly heat-tolerant versions of warm weather crops; for example, tomatoes that demonstrate the ability to set fruit even under heat stress. See individual product copy descriptions for variety-specific information.
139 Products
Sort By:
Starfighter
Pelleted Lettuce Seed
Uniform, disease-resistant green leaf with excellent heat tolerance.
Happy Rich
(F1) Broccoli Seed
Vigorous mini broccoli for successful summer crops and sweeter flavor.
Salanova® Hydroponic Green Sweet Crisp
Pelleted Lettuce Seed
High-yielding, crispy green leaf with excellent shelf-life.
Truchas
Organic Pelleted Lettuce Seed
Compact, filled-out mini heads that are dark red even in the North.