Sapodilla Growing in the Florida Home Landscape1
Scientific name: Manilkara zapota
Common names: English—naseberry, chikoo, chiku, dilly. Spanish—chicle, chicozapote, níspero, zapote, zapotillo.
Scientific name synonyms: Manilkara achras, Achras sapota, A. zapota, Sapota achras
Relatives in same family: mamey sapote, canistel, caimito, lucumo, green sapote, abiu, satin leaf.
Origin: Mexico (Yucatan Peninsula) and Central America
Distribution: The United States, Caribbean, Central and South America, Asia, India, Sri Lanka, the Philippines, Australia, New Zealand, and South Africa.
Importance: Sapodillas are extensively planted and consumed locally in Mexico, Central America, the Caribbean, India, and some Asiatic countries.
Invasive potential: Sapodilla has been assessed by the IFAS Invasive Plants Working Group as invasive in south and central Florida and is not recommended by UF/IFAS for planting. For more information see: Fox, A. M., D. R. Gordon, J. A. Dusky, L. Tyson, and R. K. Stocker, (2005) UF/IFAS Assessment of the Status of Non-Native Plants in Florida's Natural Areas [Cited from the internet (November 2016) at http://assessment.ifas.ufl.edu/].
Sapodilla trees are medium to large trees with a pyramidal to rounded canopy. These long-lived trees grow slowly, but after many years may reach 60 to 100 feet in height. Sapodilla trees are well adapted to subtropical and tropical climates. The tree has ornamental value and may be used for landscaping. Branches are horizontal or drooping. A milky latex exudes from all tree parts. This latex is known as chicle and was used to make chewing gum.
The foliage is evergreen. Leaves are 2 to 5 inches (5–20 cm) long, stiff, pointed, and clustered at the ends of shoots. The leaves are pinkish when newly emerged and light green to dark green at maturity.
Flowers are borne singly or in clusters in leaf axils near the tips of branches. Flowers are small, bisexual, off-white, bell-shaped, and measure about 3/8-inch (9.5 mm) in diameter.
The fruit is a berry with a scurfy brown peel. Fruit may be round to oval-shaped or conical, and 2 to 4 inches (5–10 cm) in diameter. They weigh 2.6 oz to 2.2 lbs (75 to 1000 g). The pulp has a sweet to very sweet (19–24°Brix), pleasant flavor. Seed number varies from 0 to 12. Seeds are dark brown to black, smooth, flattened, shiny, and 3/4-inch (1.9 cm) long.
When fruit reaches maximum size, it may be picked and allowed to ripen off the tree. From experience, one can judge maturity of fruit of a variety or selection by its size and appearance.
Season of Bearing
In Florida, trees mainly bear from May to September, but fruit may mature throughout the year.
Seeds should not be used for producing new trees because it takes a long time for trees to begin production and there is also a lot of variability among seedling trees. There have been a number of new cultivars developed in Florida, India, the Philippines, Mexico, and Venezuela. Table 1 shows a list of varieties and some of their characteristics. Varieties with good horticultural characteristics should have high yield, moderately large to large fruit, and a smooth, sweet and aromatic pulp with little or no grittiness.
Sapodillas are adapted to tropical and warm sub-tropical climates. Trees are well adapted to south Florida and to the coastal areas of Florida as far north as Tampa and Merritt Island.
Environmental Stress Tolerance
Young sapodilla trees have been observed to defoliate or decline due to lack of water; therefore, young trees should be watered periodically during dry periods. Mature sapodilla trees are tolerant of dry soil conditions. However, for optimum fruit production and quality, periodic irrigation during long dry periods is recommended from flowering through harvest. In the home landscape, well established sapodilla trees generally do not require regular watering to produce satisfactorily.
Sapodilla has been observed to be moderately tolerant of excessively wet or flooded soil conditions. However, prolonged excessively wet or flooded soil conditions may reduce tree growth and crop yields.
Young sapodilla trees may be severely damaged or killed at 30 to 32°F (-1 to 0°C) or below but mature trees may withstand down to about 26°F (-3°C) for a few hours without major damage.
Sapodilla trees are tolerant of windy conditions and young trees generally do not have a problem with establishment on windy sites. Mature trees should be limited to 12 to 15 feet (3.7–4.6 m) in height to help reduce the chances of toppling due to hurricane-force winds.
Sapodillas grow well near the seashore, indicating a good tolerance to sea salt spray. Their tolerance to saline soils and irrigation water is not known. Typical symptoms of salt stress include marginal and tip necrosis of leaves, leaf browning and drop, stem dieback, and tree death.
Although seeds can be used for propagation and are used for selection of superior types, they should not be used for home plantings. Marcottage (air layering) has not been an effective propagation method. Side veneer and cleft grafting on to seedling sapodilla rootstock are the most common grafting methods. Chip budding can also be used. Scions or bud sticks are chosen from young terminal shoots. Cover the grafted scions completely with grafting tape. The best time to graft is late summer and early fall.
Top working undesirable mature sapodilla trees may be accomplished by cutting trees back to a 3-ft-height (1-m) stump, white washing the entire stump and then veneer-grafting several new shoots when they reach ½ inch (13 mm) in diameter or larger.
Seedling trees usually begin bearing in 6 to 7 years or more. Grafted trees may begin to bear in the second to fourth year after planting. After 10 years, a good cultivar may bear 150 to 400 pounds (45–180 kg) of fruit per year. This yield may keep increasing until about the twelfth to fifteenth year after planting depending on plant size and cultural practices.
Isolated sapodilla trees may not be productive because some sapodilla cultivars are self-incompatible. In self-incompatible cultivars, the flowers require cross-pollination by another sapodilla seedling or variety to produce fruit. Other varieties may not require cross-pollination but produce more fruit when cross-pollinated.
Although sapodillas grow slowly, trees that are not pruned eventually need a lot of space because they will develop a large canopy. Sapodilla trees in the home landscape should be planted 25 feet (7.6 m) or more feet away from the nearest tree and/or structure. Trees planted too close to other trees or structures may not grow normally or produce much fruit due to shading.
Sapodillas are well adapted to a wide range of soils but grow best in well-drained, light soils. Trees are especially well adapted to the rocky, highly calcareous soils of south Florida. Although sapodilla trees are moderately tolerant of occasional flooding or excessively wet soil conditions, they will not perform well in poorly drained soils.
Planting a Sapodilla Tree
Proper planting is one of the most important steps in successfully establishing and growing a strong, productive sapodilla tree. The first step is to choose a healthy nursery tree. Commonly, nursery sapodilla trees are grown in 3-gallon (11-liter) containers, and trees stand 2 to 4 feet (0.9–1.2 m) from the soil media. Large trees in smaller containers should be avoided because the root system may be "root bound." This means all the available space in the container has been filled with roots to the point that the tap root is growing along the edge of the container in a circular fashion. Root-bound root systems may not grow properly once planted in the ground.
Inspect the tree for insect pests and diseases and inspect the trunk of the tree for wounds and constrictions. Select a healthy tree and water it regularly in preparation for planting in the ground.
In general, sapodilla trees should be planted in full sun for best growth and fruit production. Select a part of the landscape away from other trees, buildings and structures, and power lines. Remember sapodilla trees can become very large if not pruned to contain their size. Select the warmest area of the landscape that does not flood (or remain wet) after typical summer rainfall events.
Planting in Sandy Soil
Many areas in Florida have sandy soil. Remove a 3- to 10-foot-diameter ring of grass sod (0.9- to 3.1-m). Dig a hole 3 to 4 times the diameter and 3 times as deep as the container the sapodilla tree came in. Making a large hole loosens the soil next to the new tree, making it easy for the roots to expand into the adjacent soil. It is not necessary to apply fertilizer, topsoil, or compost to the hole. In fact, placing topsoil or compost in the hole first and then planting on top of it is not desirable. If you wish to add topsoil or compost to the native soil, mix it with the excavated soil in no more than a 1:1 ratio.
Backfill the hole with some of the excavated native soil. Remove the tree from the container and place it in the hole so that the top of the soil media from the container is level with or slightly above the surrounding soil level. Fill soil in around the tree roots and tamp slightly to remove air pockets. Immediately water the soil around the tree and tree roots. Staking the tree with a wooden or bamboo stake is optional. However, do not use wire or nylon rope to tie the tree to the stake because they may eventually damage the tree trunk as it grows. Use a cotton or natural fiber string that will degrade slowly.
Planting in Rockland Soil
Many areas in Miami-Dade County have a very shallow soil. Several inches below the soil surface is a hard, calcareous bedrock. Remove a 3- to 10-foot-diameter ring of grass sod (0.9- to 3.1-m). Make a hole 3 to 4 times the diameter and 3 times as deep as the container the sapodilla tree came in. To dig a hole, use a pick and digging bar to break up the rock or contract with a company that has augering equipment or a backhoe. Plant as described in the previous section.
Planting on a Mound
Many areas in Florida are within 7 feet (2.1 m) or so of the water table and experience occasional flooding after heavy rains. To improve plant survival, consider planting fruit trees on a 2- to 3-foot-high by 4- to 10-foot-diameter mound of native soil (0.6- to 0.9-m by 1.2- to 3.1-m) .
After the mound is made, dig a hole 3 to 4 times the diameter and 3 times as deep as the container the sapodilla tree came in. In areas where the bedrock nearly comes to the surface (rockland soil), follow the recommendations for the previous section. In areas with sandy soil, follow the recommendations from the section on planting in sandy soil.
If there is a potential for flooding, plant the tree on a large hill or mound made up of native soil, 2 to 3 feet high by 4 to 6 feet in diameter (0.6 to 0.9 m by 1.2 to 1.8 m).
Care of Sapodilla Trees in the Home Landscape
A calendar outlining the month-to-month cultural practices for sapodilla is shown in Table 2.
Sapodilla is not demanding in its fertilizer requirements (Table 3). After planting, when new growth begins, apply 1/4 lb (113 g) of a young tree fertilizer such as a 6-6-6-2 (% nitrogen-% phosphate-% potash-% magnesium) with minor elements with 20 to 30% of the nitrogen from organic sources. Repeat this every 8 to 10 weeks for the first year, then gradually increase the amount of fertilizer to 0.5, 0.75, 1.0 lb (227 g, 341 g, 454 g) as the tree grows. Use 2 to 3 minor element (nutritional) foliar sprays per year from April to September.
Sapodilla trees generally do not develop iron deficiency, even when grown in the rocky, calcareous, high-pH soils of Miami-Dade County. If iron deficiency symptoms appear (chlorotic leaves with green veins), apply iron. For trees in acid to neutral soils, apply dry iron sulfate at 0.25 to 1 oz per tree to the soil 2 to 4 times per year; water the iron into the ground. In alkaline soils with a high pH, drench the soil next to the tree trunk with iron chelate 1 to 2 times per year from June through September. Table 2 summarizes the fertilizer recommendations for sapodillas.
For mature trees, 2.5 to 5.0 lbs of fertilizer per application 2 to 3 times per year is recommended. The fertilizer mix (NPK) should also include phosphate (P2O5) and potash (K2O); use a 6-6-6, 8-3-9 or similar material. Use 2 to 3 minor element (nutritional) foliar sprays per year from April to September.
Newly planted sapodilla trees should be watered at planting and every other day for the first week or so and then 1 to 2 times a week for the first couple of months. During prolonged dry periods (e.g., 5 or more days of little to no rainfall) newly planted and young sapodilla trees (first 3 years) should be watered once a week. Once the rainy season arrives, watering frequency may be reduced or stopped.
Once sapodilla trees are 4 or more years old, watering will be beneficial to plant growth and crop yields only during very prolonged dry periods during the year. Mature sapodilla trees do not need frequent watering, and over-watering may cause trees to decline or be unthrifty.
Sapodilla has relatively few insect pests. Occasionally, several moth species (e.g., Barnisia myrsusalis) causes extensive damage to blooms in some years in Florida. The fruit of some cultivars is susceptible to the Caribbean fruit fly (Anastrepha suspensa). Periodically, other pests attack sapodilla, including the Cuban may beetle (Phyllophaga bruneri), mining scale (Howardia biclavis), green shield scale (Pulvinaria psidii), pustule scale (Asterolecanium pustulans), leafminer (Eucosmophora sp.), and Conotrachelus sp. beetle. Please contact your local UF/IFAS Extension office for current control recommendations.
There are no major diseases of sapodillas in Florida. A leaf rust (Uredo sapotae) causes minor leaf damage. Other diseases of minor importance include dry rot (Fusarium solani), septoria leaf spot (Septoria sp.), fruit rot (Phytophthora palmivora), phyllosticta leaf spot (Phyllosticta sapoticola), pestalotia leaf spot (Pestalotia scirrofaciens), anthracnose (Colletotrichum gloeosporioides), scab (Elsinoe lepagei), and phomopsis leaf spot (Phomopsis sp.). Please contact your local UF/IFAS Extension office for current control recommendations.
Weeds compete for water and nutrients. Weeds may be controlled by herbicide applications of registered materials, by hand weeding, and/or by mulching.
Sapodilla Trees and Lawn Care
Sapodilla trees in the home landscape are susceptible to trunk injury caused by lawn mowers and weed eaters. Maintain a grass-free area 2 to 5 or more feet (0.6 to 1.5 m) away from the trunk of the tree. Never hit the tree trunk with lawn mowing equipment, and never use a weed eater near the tree trunk. Mechanical damage to the trunk of the tree will weaken the tree and, if severe enough, can cause dieback or kill the tree.
Roots of mature sapodilla trees spread beyond the drip-line of the tree canopy, and heavy fertilization of the lawn next to sapodilla trees is not recommended because it may reduce fruiting and fruit quality. The use of lawn sprinkler systems on a timer may result in over-watering and cause sapodilla trees to decline. This is because too much water too often applied causes root rot.
Mulching sapodilla trees in the home landscape helps retain soil moisture, reduces weed problems next to the tree trunk, and improves the soil near the surface. Mulch with a 2- to 6-inch (5- to 15-cm) layer of bark, wood chips, or similar mulch material. Keep mulch 8 to 12 inches (20–30 cm) from the trunk.
Tree Training and Pruning
The development of a strong limb framework is important to allow sapodilla trees to carry large crops of fruit without limb breakage. If the tree is leggy and lacks lower branches, remove part of the top to induce lateral bud break on the lower trunk. In addition, shoot tip removal (1 to 2 inches) of new shoots of about 3 feet in length, once or twice between spring and summer will force more branching and make the tree more compact. Remove any limbs that have a narrow crotch angle because these may break under heavy fruit loads.
As trees mature, most of the pruning is done to control tree height and width and to remove damaged or dead wood. Trees should be kept at a maximum height of about 12 to 15 feet (3.7 to 4.6 m). If the canopy becomes too dense, removing some inner branches will help in air circulation and light penetration. Another pruning objective is to remove dead, damaged, or diseased branches. Low branches should not be cut, however, unless they touch the soil. Cultural practices, e.g., picking, spraying, and pruning, are easier on small trees.
For mature, very large sapodilla trees in the home landscape that may pose a risk of damaging adjacent buildings or trees, we recommend a professional arborist provide the pruning services. Make sure the arborist is licensed, has insurance, and knows the local ordinances pertaining to fruit tree pruning in your area.
Harvest, Fruit Maturity, Ripening, and Storage
For the beginner, fruit maturity is difficult to judge. Immature fruit may not soften for many days, may not develop optimum sweetness and flavor, and may contain pockets of coagulated latex within the flesh. Fruit picked at optimum maturity usually ripen in 4 to 10 days. If you do not know the time of fruit maturity, you may wait until some fruit drop and then begin to harvest those of similar size. Other indicators of maturity are fruit size, loss of peel scurfiness, and a change in skin color from brown to amber. Another test is to lightly scratch the skin; if it is tan it can be picked, but if it is green or oozes latex, the fruit is not fully mature.
Sapodilla trees may have harvestable fruit year-round, though there is a main season for each cultivar (Table 1). As the season for each cultivar advances, the ripening time decreases. Ripe fruit may be stored in the refrigerator.
Uses and Nutritional Value
Sapodillas are nutritious and mostly eaten as fresh fruit (Table 4). Sherbets, milk shakes, and ice cream can be made from fresh pulp. Chicle, the latex obtained from the bark of the tree, was for many years the principal ingredient of chewing gum. Because of their beauty and tolerance to neglect, sapodilla trees may also be used as an ornamental for landscaping in south Florida.
Sapodilla cultivars in Florida.
Cultural calendar for sapodilla production of mature (bearing) trees in the home landscape.
Suggested fertilizer recommendations for sapodillas for Florida.
Nutrient value of sapodilla fruit (3.5 oz or 100 g of fruit).z