Different plants have different tolerances to cold and heat. A tender plant is one that can be easily damaged, particularly by cold. The term is usually applied only to perennial plants, as annuals are replaced yearly, and will die at the end of their growing season, anyway. Perennials are plants that can live for two or more seasons, depending on their ability to withstand cold.

You’ll find a number of different categories for tender plants. For instance, there are half-hardy perennials, which are hardier than many types of tender plants, but are not as hardy as many others. There are also subtropical plants, which are meant to be grown in specific hardiness zones within the US (generally the southern states).

Subtropical plants often have some resistance to freezing temperatures, but will not survive temperatures that drop below 0 degrees F. Finally, there are tropical plants, which are best grown in areas like south Texas and Florida, and are usually native to the Caribbean, as well as to Central America. These plants have no real resistance to freezing temperatures. In fact, they grow poorly in areas where temperatures reach 50 degrees F.

Tender plants also need considerably more sun exposure than hardy or semi-hardy plants. Most of them need at least eight hours of sun per day. Examples of these plants include zucchini and cucumbers, as well as corn. Very tender plants need up to 12 hours of sunlight per day, though. Examples of very tender plants include eggplant and okra.