Growing plums (Prunus domestica or Prunus salicina) in Florida may seem counterintuitive, given the region’s strong association with citrus and tropical fruits. Plums are deciduous trees that require a period of cold weather to thrive, naturally shedding their leaves in the fall. This biological need presents a challenge in Florida’s mild winters. Successful cultivation depends entirely on selecting specialized cultivars that have been adapted to the state’s unique weather patterns.
Understanding Plum Chill Requirements
The primary constraint dictating where plums can be cultivated is the chilling requirement. Deciduous fruit trees must accumulate a specific number of “chill hours” to successfully break winter dormancy, ensuring uniform bud break and flower development. A chill hour is defined as one hour where the ambient temperature is at or below 45°F (7°C).
Traditional European plum varieties typically require 800 to 1,200 chill hours. Japanese plums need 300 to 900 hours. The majority of Florida, particularly the central and southern regions, rarely achieves these totals. For example, areas around Orlando may only accumulate 200 to 300 chill hours, while the Miami area often records fewer than 50.
If a plum tree with a high chilling requirement is planted in a low-chill environment, it will fail to exit dormancy correctly. Symptoms include delayed and erratic leafing, sparse flowering, and a poor fruit set. Successful plum cultivation in Florida requires varieties bred explicitly to function with the limited winter cold available in the state.
Low-Chill Varieties for Florida Cultivation
The University of Florida’s Institute of Food and Agricultural Sciences (UF/IFAS) has developed specific Japanese-type plum cultivars designed to overcome the state’s climatic limitations. These varieties, often part of the ‘Gulf’ series, have exceptionally low chill hour requirements, making them viable options for home growers. Cultivars like ‘Scarlet Beauty’ require as few as 150 chill hours, while others, such as ‘Gulfbeauty’ and ‘Gulfblaze,’ need approximately 225 to 250 hours, respectively. This range makes them suitable for planting across a wide area, from the Panhandle down to the Fort Myers region.
These low-chill plums, which ripen as early as late April or May, are adapted to the mild winters and possess resistance to common diseases. They are Japanese plums (Prunus salicina) and have been bred for tolerance to plum leaf scald and bacterial spot, two issues in the humid southeastern climate. The trees are not self-fruitful and require cross-pollination to produce a reliable crop. Therefore, planting at least two different compatible low-chill varieties, such as ‘Gulfbeauty’ and ‘Gulfrose,’ is necessary for successful fruit production.
Planting and Care Guidelines
Successfully growing these specialized low-chill plums requires attention to environmental management, focusing on the challenges of high heat and humidity. Plum trees must be planted in a location that receives full sun, meaning a minimum of six to eight hours of direct sunlight daily. This ample light exposure is necessary to promote high-quality fruit production and to help manage disease pressure.
The high rainfall and naturally sandy soils of Florida necessitate using a planting site with excellent drainage. Plum trees will not tolerate standing water or perpetually soggy roots, which can quickly lead to root rot. If the native soil is heavy or poorly drained, planting on a raised bed or mound is a practical solution.
In terms of post-planting maintenance, pruning is an important part of managing the tree in a humid climate. Pruning in late winter, while the tree is dormant, helps to create an open canopy structure that improves air circulation. This increased airflow is a simple, yet effective, method for reducing the incidence of fungal diseases like brown rot and various mildews that thrive in humid conditions. Plum trees also benefit from regular fertilization, typically two to three applications of a balanced fruit tree formula throughout the spring and summer growing seasons, to support their rapid growth rate.