How to Grow Mangosteen in Zone 10

Mangosteen, or Garcinia mangostana, occurs naturally within the moist forests of Indonesia and is commonly cultivated in tropical climates around the world for its sweet, complexly flavored fruit. It is a large tree, growing to between 20 and 80 feet in height, with a pyramid-like growth habit of leathery evergreen leaves. Like many species of tropical tree, mangosteens require very specific climate and soil conditions to prosper, and may prove challenging for many gardeners. If you take measures to protect the trees against the cold, it is possible to grow mangosteens in relatively cooler climates, such as USDA zone 10.

Things You'll Need

• Vacuum flask
• 4-inch peat pots
• Medium-grit sand
• Compost
• Warming mat
• Propagation dome
• Spray bottle
• Shovel
• Tomato cage
• Clear plastic greenhouse film
• Heavy duty tape
• Straw mulch
• 1/2-inch weave bird netting

Instructions

1. Soak the mangosteen seeds in a vacuum flask filled with 90-degree-Fahrenheit water for 24 hours. Drain them for five or 10 minutes before sowing them.

2. Fill a 4-inch peat pot for each mangosteen seed with equal measures medium-grit sand and compost. Saturate the mixture with warm water. Allow the pots to drain.

3. Sow one mangosteen seed in each peat pot. Bury the seed so the top side is just below the surface with a thin layer of soil covering it.

4. Place the peat pots on a warming mat set to 85 degrees Fahrenheit. Cover the pots with a propagation dome to mimic a warm, humid greenhouse environment. Mist the soil every few days with a spray bottle to keep the top 1/2 inch moist.

5. Watch for sprouting in 30 to 45 days. Keep the mangosteen saplings in their pots until they reach 4 inches in height and have developed a few sets of mature leaves.

6. Prepare a bed for the mangosteen saplings in late spring when soil temperatures reach 70 degrees Fahrenheit. Choose a planting site with full sun, a southerly exposure and moderate protection from northern wind such as a wall or windbreak.

7. Dig planting holes that are 4 feet deep and 2 feet wide for the mangosteen saplings. Space the holes 30 feet apart. Mix the displaced garden soil with equal measures medium-grit sand and compost. Fill the hole with the soil mixture. Tamp the soil periodically as you fill the hole to force out any trapped air.

8. Plant the mangosteens in the prepared planting holes. Bury the peat pots so the upper edges and the base of the mangosteen stems are 1/8 inch below the surface of the soil.

9. Place a wire tomato cage over the top of each mangosteen sapling. Press the legs into the ground to anchor them. Wrap clear plastic greenhouse film around the tomato cage and over the top. Secure it with heavy duty tape. Leave a 1.2-inch gap between the bottom of the plastic film and the ground to allow for air circulation.

10. Water the mangosteen saplings to a depth of 1 inch whenever the soil feels dry below the surface. Keep the soil evenly moist 90 percent of the time with brief periods of partial drying.

11. Cut open the top of the plastic film after 30 days to help acclimate the trees to normal air temperatures. Remove the tomato cage completely in 45 days.

12. Spread a 2-inch-thick layer of straw mulch around the base of the mangosteen trees once seasonal temperatures begin to dip below 50 degrees Fahrenheit. Decrease watering to 1/2 inch every 10 days during winter.

13. Drape 1/2-inch weave bird netting over the crown of the mangosteen trees to protect against the cold if nighttime air temperatures are forecasted to be below 45 degrees Fahrenheit.

References

• "Handy Pocket Guide to Tropical Fruits"; Wendy Hutton; 2004