Central Florida’s subtropical climate, primarily encompassing USDA Hardiness Zones 9b and 10a, experiences a reversed growing season compared to northern latitudes. This climate demands a localized approach to vegetable gardening. The primary limiting factors are the intense summer heat and the occasional, unpredictable winter frost, not the cold. Understanding these seasonal extremes is the foundation for a successful planting schedule in the Orlando and Tampa corridor.
Defining the Central Florida Growing Climate
The Central Florida growing season is defined by a short, mild winter and a long, intense summer. Hardiness Zones 9b and 10a indicate that average minimum winter temperatures range between 25°F and 35°F. Light frosts are possible but rarely prolonged, allowing for the cultivation of cool-season crops that thrive during the spring and summer in colder areas.
The long summer, extending from late May through September, is characterized by excessive heat, high humidity, and heavy rainfall. This period is often too harsh for many traditional temperate vegetables, causing crops like tomatoes to cease production due to heat stress and poor pollination. As a result, the primary vegetable growing season is functionally the period between October and May, reversing the traditional northern planting calendar.
Planting Windows for Cool Season Vegetables
Cool-season vegetables thrive in the mild Florida winter, avoiding the intense summer heat that causes them to bolt or turn bitter. This window generally opens in late September or early October and extends through February or early March. Most of these crops prefer soil temperatures below 75°F and benefit from the cooler nighttime air.
Many cool-season crops can be planted starting in September and October:
- Leafy greens, such as lettuce, kale, collards, and spinach, can be planted from seed or transplant through January.
- Brassicas, including broccoli, cabbage, and cauliflower, are best started from transplants in September and October due to their longer maturation period.
- Quick-maturing root vegetables like carrots and radishes are effective when direct-seeded beginning in October.
English peas and beets perform well when planted in the late fall and early winter months. Planting in the fall allows plants to establish root systems before the coolest part of the winter, ensuring a strong harvest. These crops must be harvested before the prolonged heat of May signals the end of the cool-season gardening period.
Planting Windows for Warm Season Vegetables
Warm-season vegetables, including heat-loving plants like tomatoes, peppers, and squash, are planted in two distinct windows to avoid the peak mid-summer heat. The initial spring planting begins in February and March, allowing plants to mature and produce before June. Starting with transplants in February is recommended for crops like tomatoes and peppers to gain a head start.
The spring harvest must be completed before high heat and humidity become detrimental to fruit set and plant health. A second planting window opens in August and September for a fall harvest, often considered the most productive time for these crops. Starting seeds indoors in July for August transplanting is necessary to ensure plants are mature enough to fruit during the cooler fall months.
Crops like bush beans, pole beans, and summer squash can be planted in March for a quick spring harvest and again in August or early September for a reliable fall yield. Selecting heat-set or Florida-adapted varieties of tomatoes and peppers is important for both windows, as standard varieties often fail when daytime temperatures consistently exceed 90°F.
Dealing with Extreme Heat and Year-Round Crops
The period from June through August poses the greatest challenge, as high heat and humidity stress most temperate vegetable plants and encourage pests and disease. Survival strategies, rather than extensive planting, become the focus. Using shade cloth can mitigate the intensity of the afternoon sun, and heavy organic mulching helps keep the soil cooler and retains moisture.
Specific heat-tolerant crops are adapted to thrive in these demanding conditions, making mid-summer gardening possible. Okra is reliable, producing abundantly throughout the summer. Southern peas, such as black-eyed and crowder peas, also perform well in high temperatures and benefit the soil by fixing nitrogen.
Tropical greens like Malabar spinach and amaranth provide leafy alternatives that tolerate the heat and humidity when traditional spinach and lettuce cannot. Sweet potatoes are ideally planted in late spring or early summer, using slips that mature during the hottest months for a fall harvest. Tropical squashes, such as Seminole pumpkin and calabaza, are excellent choices, as they resist the pests that plague temperate squashes.