Guava is a highly valued tropical fruit, popular for home growers and commercial cultivation due to its aromatic fruit and adaptability. Propagation allows growers to either experiment with genetic variation or replicate a desirable fruit variety. Growing a tree from seed is simple and economical, but the resulting plant may not possess the exact characteristics of its parent. For cloning a specific cultivar, rooting stem cuttings provides a reliable path to a genetically identical tree. The chosen method depends on the goal: genetic consistency or simply the enjoyment of growing a guava tree.
Growing Guava Trees from Seed
Growing a guava tree from seed requires careful selection and preparation, as the seeds possess a hard coat that enforces dormancy. Freshly extracted seeds from a mature fruit should be thoroughly washed to remove all traces of pulp, which inhibits germination. To soften the coat and encourage sprouting, scarification is necessary. This can be accomplished by soaking the seeds in warm water for two weeks, or by briefly boiling them for five minutes. These treatments make the seed coat permeable to water and gases.
The prepared seeds should be planted about a quarter to a half-inch deep in a sterile, soilless germination mix, such as peat moss and perlite. Maintaining a consistent temperature in the rooting medium, ideally between 70°F and 85°F, is important for success. Under optimal conditions, germination is expected within four to eight weeks, though the process can sometimes take up to twelve weeks.
Rooting Guava Trees from Stem Cuttings
Propagating guava from stem cuttings is the preferred method for ensuring the new plant is a genetic clone of the parent, preserving the fruit’s quality, size, and flavor. The best material to use is a semi-hardwood cutting, which refers to new growth that has begun to firm up but is not yet fully woody. Cuttings should be taken from a healthy, fruiting branch and be approximately six to eight inches long, with a diameter about the thickness of a pencil (1 to 1.5 cm).
Preparation involves making a clean, angled cut just below a node. All but the top two or three leaves should be removed to reduce moisture loss through transpiration. The basal end of the cutting should then be dipped into a rooting hormone powder, which significantly increases the success rate of root initiation.
The prepared cutting is inserted into a well-draining, sterile rooting medium, such as a mix of peat moss, perlite, or silt, ensuring the medium is kept moist. Some propagators wound the bark on the lower portion of the cutting to facilitate the callusing process before planting. The cutting is stimulated to form adventitious roots, typically within six to eight weeks.
Ideal Environmental Conditions for Rooting
The success of both seed germination and cutting propagation relies on maintaining precise environmental controls. The ideal time to begin propagation is during the late spring and summer months, as the naturally warm weather is conducive to root development. High ambient temperatures accelerate the plant’s metabolism, which encourages the development of new roots and shoots.
A temperature range of 75°F to 85°F is optimal for the rooting medium, as temperatures below 65°F can significantly inhibit growth. Providing bottom heat with a warming mat is often recommended to maintain this temperature consistently.
Maintaining high humidity is equally important for unrooted cuttings, which lack the means to absorb adequate water from the soil. This is often achieved by covering the pot with a clear plastic dome or bag, and misting the leaves frequently helps prevent desiccation. The propagating environment should be placed in an area that receives bright but indirect light, as intense, direct sunlight can scorch the delicate new leaves.
Caring for the Young Sapling
Once roots have successfully formed on a cutting or the seedlings have developed two to four sets of true leaves, the young plant must be gradually acclimated to a normal environment. This process, known as “hardening off,” involves incrementally reducing the humidity and increasing exposure to ambient air. If a humidity dome was used, it should be opened for a few hours each day, with the duration of exposure increasing over one to two weeks to prevent shock.
Potting and Initial Care
The next step is potting up the new sapling into a larger container, which should be a few inches wider than the current pot and possess excellent drainage. A high-quality, well-draining soil mix rich in organic matter, such as a balanced garden soil amended with compost, is recommended. For the first year, the young tree requires consistent moisture; the soil should be kept evenly moist but never saturated to avoid root rot.
Fertilization and Transplanting
Initial feeding should begin a few months after transplanting, using a balanced fertilizer such as one with an NPK ratio of 6-6-6 or 8-8-8. This should be applied every two to three months during the growing season. If the young guava is destined for a permanent spot in the garden, it should be transplanted in early to mid-spring to a location that receives full sun and offers protection from frost or freezing temperatures.