Contributed by Dr. Martin Price, ECHO’s founding CEO
Low chill apples bear even farther south than ECHO in Florida, and may be a unique addition to your yard. Attractive white apple blossoms will appear during Feb-March and give way to fruit (smaller than standard apples) in June. They remain small trees, growing to about 15 feet. Apples prefer slightly acidic and well- drained soils and perform best in full sun. The trees will need a complete fertilizer with micronutrients.
All apples need a dormant period in order to bloom and produce fruit. Farther north that occurs naturally due to cold weather. You will see references to “chilling hours” required for different varieties of apple and other temperate fruits. Many years we may not see that many chilling hours. But you can force dormancy by defoliating by hand in late fall. In the early spring of 1982 we planted our first subtropical apples, 2 each of 4 varieties, and on mounds because of poor drainage. When winter came the leaves looked “old” but did not fall off. We found that by simply surrounding branches near the tip with one hand and moving quickly toward the trunk the leaves on that branch would all be gone within seconds. Yields of apples were not impressive, except for one tree that produced 50 apples (which we turned into an apple pie). Trees went into decline after that and we lost interest in growing them.
Trees should be pruned lightly in late winter to promote new growth. Because flowering, fruit development and spring vegetative growth all occur during some of Florida’s hottest and driest months (April – June), irrigation is critical for succeeding with apples. To conserve moisture, mulching is highly recommended as long as mulch is not in contact with the trunk. Low chill apples produce in Florida, but are susceptible to anthracnose, fire blight, and root fungus. Apples require cross-pollination with two different cultivars to ensure decent production. The low chill varieties listed below require 50 – 150 chill hours for strong flowering and vigorous growth. Chill units are the number of hours that the temperature stays between 32-55º F. Most effective chilling occurs with continuing temperatures below 45 º F.
‘Anna’ has red skin and is the most widely planted apple cultivar in Florida. The fruit of ‘Anna’ resembles that of ‘Red Delicious’ more than other low-chill apple cultivars. Originally from Israel, this large apple can be eaten green similar to ‘Granny Smith,’ or can be allowed to ripen to desired sweetness.
‘Dorsett Golden’ looks like a ‘Golden Delicious’ apple with golden skin and sometimes a red blush. A Mrs. Dorsett discovered a seedling apple tree growing in the Bahamas in the 1960’s (perhaps from a seed from a ‘golden delicious’ apple that she may have planted.) This crisp and juicy cultivar produced well in the Bahamas with an excellent flavor and has been propagated by grafting ever since.
Perspective. A subtropical apple tree can be interesting to SW Florida homeowners because they find it a fun challenge or miss having apple trees on their property like they used to grow “up north.” Frankly it is more of a curiosity for most local homeowners, usually with marginal success. Almost any apples purchased in a grocery store will be larger and at least as tasty. ECHO sells subtropical apples because fruit enthusiasts enjoy the challenge. But for most of our customers who have limited space for trees, we recommend getting acquainted with the many, many kinds of tropical fruit trees that will grow here easily and offer many delicious tropical tastes. Many tropical fruits are seldom if ever found in local grocery stores. Ask our nursery staff members for help in learning about some of their favorites.