IFAS Palm Beach County Cooperative Extension Service
The cashew nut, Anacardium occidentale, is native
to Brazil and is planted throughout the tropical regions of the world
where it is a very important economic crop for some countries. Trees
grow in protected areas in South Florida and reach a height of about
30 feet. The trees have large leathery alternate leaves, 5-7 inches long
and prominently veined; the small fragrant pinkish flowers are produced
from early spring through early summer.
The fruit formed by the cashew tree is very unusual in
that it looks like a small pear with the cashew nut hanging from the bottom
of it. The cashew apple, as it is called, is about 2 inches in diameter
and 3 to 4 inches in length in some varieties. The trees produce fruit very
quickly, usually about 3 months after flowering; the fruit at maturity can
be either bright red, orange-red or yellow in color, and is very aromatic.
The cashew apple is often used in tropical regions for many important products
such as wine, jellies, or refreshing drinks. The edible nut, however, is
the most highly prized part of the the fruit, and is roasted and packaged
for shipment to distant markets.
The cashew is a relative of poison ivy and the oil in
the nutshell can cause a rash or other irritation to the skin--this
why the nuts must be heated in order to render the oil less caustic.
Never eat cashews raw since this caustic oil can cause significant problems
for most people. After roasting, however, the cashew is one of the most
delicious of nuts and is rich in protein and fat; the oil which is in the
spongy layer of the shell is used in many commercial applications.
Cashews are easily propagated by seed, and seedlings
may bear flowers by the second year when they are less than 3 feet in
height. As long as they have good drainage, trees grow well over a wide
range of soil types. Young trees must be protected from low temperatures
because they will be damaged or even killed at 32°F. Older trees may
have significant damage caused by frost or freeze, but usually will make
a recovery. When planted in the landscape, trees should be in sheltered
locations protected by more cold-hardy trees or buildings for optimum growth.
Cashews should be fertilized every 3 to 4 months with
a good-quality complete fruit tree-type fertilizer and are very drought-tolerant,
although they will grow better when supplied with regular irrigation. Superior
varieties of cashews are available in many tropical countries, but most
of the ones grown in Florida are seed-grown. If you have access to superior
varieties, they can be propagated by veneer grafting, budding, or air-layering.
There are very few, if any, serious pests of cashew; however, during the
spring dry season, thrips may occasionally attack foliage and cause some
defoliation.
© MM, MMXIII, MMXVI
