Inflorescence (Flowers) White, about 1 inch (2.54 cm) in diameter, borne singly or in small groups (cymes) in axils of leaves of recent growth. Self-pollination is possible but cross-pollination by insects results in higher yields.
Guava are well adapted to warm subtropical to tropical climatic conditions. Ideal temperatures for growth and production range from 73′ to 82’F (23–28 C). Temperatures below 60’F or drought cause growth to slow or cease.
Cold stress: Young guava plants may be killed by temperatures of 27′ to 28’F (-3′ to -2’C).
Prolonged over-watering may lead to fruit and leaf drop, leaf chlorosis, stem dieback, and tree death.
Guava are tolerant of prolonged drought and stop active vegetative growth during this time. Immature (soft) wood and leaves may wilt, and drought during fruit set and development may decrease fruit set and size, respectively. Drought stress is sometimes used alone or in conjunction with other cultural practices (e.g., pruning) to induce off-season flowering and fruit production.
Guava may be propagated by seed, however they do not come true from seed, and fruit production may not begin for 3 to 8 years. Cultivars are vegetatively propagated by air layering (marcottage), stem cuttings, grafting and budding. The best material for stem cutting propagation is recently matured, terminal wood. Stem cuttings should be 6 to 8 inches long with 2 to 3 leaves. The cuttings should be placed in sterile media, in a mist bed. Bottom heat (75′ to 85’F/24′ to 29’C) and/or dipping cuttings in rooting hormone are beneficial.
A soil pH of 4.5 to 7 is ideal. Fertilizer mixtures containing 6 to 10% nitrogen, 2 to 4% available phosphoric acid, 9 to 15% potash, and 4 to 6% magnesium give best results.
Newly planted guava without lateral branches should be pruned at about 1 to 2 ft to induce lateral branching. During the first year, 3 to 4 well distributed lateral branches should be selected and allowed to grow 1 to 2 feet and then tipped to induce further branching. New shoots formed from tipping should also be tipped. Subsequently, vigorous water sprouts or ill-placed shoots should be removed.
Guava that are bearing fruit may be kept small (3 to 6 ft high). Regardless of the tree size desired, selective pruning may maintain trees at the desired height and spread and open the canopy to wind movement and sunlight penetration.
Off-season fruit production: Pruning may be used to induce off-season flowering and fruit production. Guava flower on new succulent, vigorous new growth arising from either lateral buds on older wood, or at the ends of shoots. A period of 2–3 weeks without watering and then pruning will force new vegetative growth and flowering. Many times withholding water is not necessary.