Theobroma cacao, or Cacao, is an evergreen tree native to the wet lowlands of Central and South America. The seeds yield the cocoa and chocolate of commerce after fermentation and roasting. Trees in nature will reach 25 feet (7.6 m) in height. Leaves are leathery and will reach 12 inches (30 cm) long. The new growth is red and pendent, which is not an unusual habit for tropical plants. Bark is smooth, grey-brown in color. Trees should bear fruit in 4 years from seed. Our trees are 2 years old and since they were grown from seed, they will likely not produce fruit for another 2-3 years. The trees can be grown in the landscape in USDA zone 10.
Blooming: Our plants will not bloom for a few more years. Flowers will be borne on the trunk and older branches. They are long pedicelled. The calyx is pinkish with yellowish petals about 0.5 inches (1.25 cm) across and 0.37 inches (0.9 cm) long. Fruit will be yellow, purple, or brown, 10 ribbed and about 1 foot (30.4 cm) long. Seeds are ellipsoid to 1 inch (2.54 cm) long in a mucilaginous pulp that bears little flavor resemblance to processed chocolate -- it is typically extremely bitter and unpleasant to most tastes until processed.
Culture: Theobroma cacao needs light to full shade with a moist rich soil mix. We use a soil mix consisting of 2 parts peat moss to 2 parts loam to 1 part sand. The plants are native to wet lands and should be kept moist at all times. They should be fertilized with an organic fertilizer; we use fish emulsion on ours. By trail and error, we learned that commercial fertilizers are detrimental to plant health. Plants just do better with organics. We grow ours under 52% shade all year long. More sun tends to burn the leaves. Although they are tropical in nature, during the winter months in the greenhouse, we do restrict the water somewhat and withhold fertilizers during this period. Plants are never allowed to dry completely during this period.
Propagation: Theobroma cacao is best propagated from seed. The seed need to be fresh for best germination. I have tried to germinate seeds that are a month or older with very little luck. Seed that are 3 weeks old germinated in 21-30 days at 72°F (23°C) and we got 100% germination rate. The older the seed the germination rate dropped dramatically.
Theobroma cacao was featured as Plant of the Week August 1-7, 2008.
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Cal's Plant of the Week was provided as a service by the University of Oklahoma Department of Microbiology & Plant Biology and specifically the late Cal Lemke, who used to be OU's botany greenhouse grower and an avid gardener at home as well. If the above links don't work, then try the overview site. You may also like to look at the thumbnail index. ©1998-2012 All rights reserved.