Cherry guava (scientific name P. cattleyanum) is a plant related to the myrtle family (Myrtaceae). It can be considered either a large shrub or a small tree and was originally native to the eastern areas of Brazil. Because of its fruit and ornamental value, cherry guava was cultivated in many areas with tropical and subtropical climates and later became an invasive plant in many parts of the world. It is considered to be a dangerous weed around the Indian and Pacific Oceans and especially in Hawaii, where it is classified as the worst local invasive species. The cherry guava fruit is very similar to the normal guava (scientific name P. guava) but usually considered to be more attractive but smaller in size. Two other guava species have commercial value: the Guinea guava (P. guineense) and the Costa Rican guava (P. friedrichsthalianum).
It doesn't usually grow higher than 2 or 4 m but cherry guavas with a height of 12 m have been reported. Cherry guava is slightly more resilient than the normal guava and some varieties can even tolerate a moderate amount of frost. Leaves are about 4.5 cm long, with an oval or elliptical shape, visible veins and a surface that can be either similar to leather or slightly waxy. Flowers of cherry guava have a size of 6 cm, with a tubular shape and consist of 5 petals. They either grow alone or in axillary clusters of 3 and are white in color, with a pleasant fragrance. After 3 to 6 years of life, the plant starts to produce fruits, which have a slightly oval shape similar to a walnut, with a length of around 4 cm. When ripe, the fruit varies in color from yellow to red or even purple, with a thin skin. Similar to an apple or blueberry, the cherry guava preserves some remains of the calyx on the top. The flesh is white or yellow, very juicy, with a large number of small soft seeds.
Cherry guavas are delicious when consumed fresh, with an attractive sour taste caused by the very high content of vitamin C. Cherry guava can also be prepared in many ways, into jelly, jam, ice cream, sorbet or juice. Boiling the fruit in water with added sugar produces a paste that is useful in bakery products as a filling.
Initially cultivated in many parts of the world, the cherry guava has escaped from gardens and orchards and is now classified as a dangerous invasive species. Examples include the US states of Hawaii and Florida, as well as Australia, New Zealand, Polynesia, Mauritius, the Seychelles, Norfolk Island and many other tropical islands. It is considered extremely dangerous because it produces a lot of seedlings and root suckers that form very dense thickets, which shade and eliminate native plants. Cherry guava is even able to compete with intact rainforests. The International Union for the Conservation of Nature (IUCN) has included cherry guava on its list of the worst 100 invasive species in the world.
The cherry guava has a content of vitamin C of 11-50 mg per 100 g, which is a lot lower than in a normal guava fruit. The plant's leaves are very rich in compounds with a strong antibacterial action, which are able to kill some very dangerous strains of Gram-positive bacteria that resist all known antibiotics. Leaves are also rich in other bioactive compounds such as essential oils like b-caryophyllene, as well as flavonoids, saponins and tannins. The essential oils can be extracted from the leaves after distillation. Various types of antioxidants are found in all parts of the plant. Traditionally, the fruits and leaves have been used to treat diarrhea, hemorrhage and colic.
The cherry guava fruit is a great choice for a healthy diet since it has a high content of fibers, protein and vitamins, while being low on calories. Like most fruits, it provides a lot of fiber, which helps with digestive issues and can reduce cholesterol levels. At the same time, a diet rich in fibers can help you lose weight. The cherry guava is less sweet than most fruits but still has a delicious taste.
The main nutrient found in cherry guavas is dietary fiber, known for its digestive benefits. It also includes an amount of vitamin C. The amount of fiber makes it an excellent choice for digestion. Fibers accelerate the transit of food through the small intestine and prevent many conditions such as constipation. For this reason, cherry guavas are both delicious and healthy as a desert choice.
The fiber content of cherry guavas not only helps digestion but also reduces high blood pressure and facilitates weight loss. All of these properties are very useful for people who suffer from diabetes. Consuming fibers reduces the risk of blood glucose spikes by balancing the supply of sugar.
One very exciting health benefit of the cherry guava is the effect against cancer. This is due to the high content of polyphenols and antioxidant compounds that can neutralize free radicals and stop them from harming tissues. These natural compounds can limit or even stop the growth of tumours. Cherry guavas have a content of lycopene, which is a very strong antioxidant that was proven by several tests to be effective against cancer.
Another key nutrient in cherry guavas is vitamin A. This vitamin is important for skin health and for the eyes and a lack of it can cause poor vision and the so-called night blindness. A proper supply of vitamin A maintains visual acuity and is good for health in general. Cataract is one example of eye disease that can be prevented by consuming vitamin A.
The mix of fiber and vitamin C found in these fruits is very good for digestive health. As an astringent, the cherry guava flesh eliminates excess mucus from the stomach and intestines, while killing various pathogens. It is recommended against dysentery, which is a disease that can have serious consequences.
An essential mineral found in cherry guavas is copper. While not as well-known as other minerals, copper actually plays an important role in the human body because it is needed by the thyroid gland, which produces hormones critical for our health.
The high amount of dietary fiber supplied by these fruits is excellent for digestion because it provides bulk to the stool. As it bulks up, the stool can move through the intestines easily and gets excreted. In addition, fiber reaches the blood stream and can scrape cholesterol deposits from the walls of arteries, which is essential for heart health. It also reduces the amount of sugar in the blood.
Vitamin B complex can also be found in cherry guavas, especially the vitamins B2 and B3. Since these are considered crucial for normal brain operation, cherry guavas are known to improve mental health. Vitamin B3 is particularly important because studies have proven that it boosts cognitive functions and the flow of blood to the brain.
Few people know that a cherry guava provides a massive amount of vitamin C, about 5 times more than oranges and other citrus fruits. Vitamin C has many uses in the body and a lack of it leads to scurvy. It is also a powerful antioxidant and can boost immunity, preventing flu, colds and infections.
The plant has been naturalized in many parts of the world and fruits are usually available from cultivated stands. It can be consumed fresh or prepared as juices, jams, sherbets or jellies. In most areas, the cherry guava doesn't have much commercial importance and is only sold locally. However, it is economically important in places like the French island of Réunion, where it is cultivated widely. Cherry guava grows very slowly, which makes it also useful as an ornamental garden or hedge tree. It also provides edible fruits and it is considered attractive for the green shiny foliage. Sadly, the widespread garden use has made it a dangerous invasive species in some areas.
The original native area of the cherry guava is in Eastern Brazil, in areas close to the ocean. However, it has quickly adapted to many tropical climates and has become a dangerous weed. Some Caribbean islands and the US state of Hawaii are particularly affected. It tends to grow at high elevations in very hot climates, in order to find a temperature closer to its optimal. Varieties with yellow fruits don't tolerate cool temperatures and favour lower elevation.
The species is very resilient and can easily be cultivated in US states with tropical climates, such as California or Florida. It can only be killed by serious frost and will also thrive and produce fruits if grown in a container. It can survive short periods of drought but requires a lot of water and a position with full sun exposure for best results. Ample water is especially needed for the fruit to ripen and develop properly. Psidium cattlenium var. lucidum is the scientific name of the yellow variety, which is also cold tolerant but not as hardy as the normal tree.
Cherry guavas can be propagated from seeds but these don't germinate too easily. The problem is the long period required, of a minimum 4-6 weeks before it can properly germinate. In many location, such a long period of time is not available. Moist and sterile soil is the best option and the seeds should be planted about 1/4-1/2" deep. Soil temperature is also very important, if below 60-63 °F the seeds will not germinate at all, with the optimum temperature being a constant 70-85 °F.