Origin
The Guava is thought to be native to Mexico and the northern part of Central America. It is now cultivated in most of the tropics.
Uses
The pulp of the Guava is eaten fresh out of hand or made into jams and sauces. The leaves and fallen fruit are eaten by cattle as it is a common pasture tree growing wild. The tree can be kept pruned and serve as an attractive, edible hedge. Nectar in the blossoms attracts honeybees. Tannin, found in the leaves and bark and young fruit will produce brown stain on clothing and hands. Because of the astringency of all parts of the tree, it is used in local medicine
Cultivation
Guavas are a RAPID-growing tree producing fruit 2-4 years from seed. Left unpruned, it can reach a height of 12 m (40 ft). Guavas can tolerate some flooding, drought, salt, alkalinity, limestone and poor soils that would barely support other fruit trees. Mulching and irrigation will improve plant growth and fruit yields in low moisture sites. In areas with a distinct winter season and rainfall of 40-80 inches (1,000-2,000 mm) each year, Guavas will yield the best crops. It cannot tolerate even a light frost but when cut to the ground, will grow again and produce fruit. Propagation is by root cuttings or by air layering. The Guava does not always grow true to seed so vegetative propagation gives the most reliable results.
Harvesting and Seed Production
Guavas ripen mainly in warm summer months with a smaller crop in early fall. For eating fresh, pick before fully ripe but for saving seed, let ripen on the tree. The fruit needs to be harvested over a long period of time. When seeds from the best fruit are freed of their pulp, then dried in the open air, they stay viable for months. When ready to plant, seeds need to be boiled in water for 5 minutes or soaked in water for two weeks.
Pests and Diseases
Guavas are susceptible to root damage from nematodes, fruit damage from worms that burrow into the fruit, and leaf damage from beetles and thrips. Fungus will attack leaves in early spring but new foliage grows quickly. As the fruit ripens, fruit flies, bats and birds feed on it.
Cooking and Nutrition
Fresh fruit is easily bruised and is well suited to jams or Guava paste. It needs early harvesting and careful handling if destined for a commercial market. The skin is very high in ascorbic acid and vitamin C.
References
Morton, J. 1987. Guava. p. 356–363. In: Fruits of warm climates. Julia F. Morton, Miami, FL.