Psidium guajava, commonly called guava, is a tropical evergreen shrub or small tree native to the Caribbean, Central America, and South America. Now widely cultivated worldwide, guava is valued for its nutrient-rich, vitamin C-rich fruits and ornamental appeal. Guava seed germination is moderately slow but straightforward when proper warm, moist conditions are maintained, typically taking 2-12 weeks with good germination rates above 80-90%
Before sowing
Warm water soaking for 24 hours is essential to break seed dormancy and improve germination rate. Optional light scarification may provide additional benefit. Avoid cool or cold soaking
Sowing
What to expect
Tips
Provide consistent warmth (75-85°F/24-29°C) using a seedling heat mat - this is critical for success as germination fails in cool soil. Maintain high humidity by covering containers with plastic until seedlings emerge. Once seedlings appear, provide bright light (full sun or grow lights) and gradually reduce humidity. Transplant into larger containers once several true leaves develop. For faster results, use alternating day/night temperatures or boiling water treatment before soaking. Ensure excellent drainage to prevent damping-off. Guava seeds are recalcitrant (moisture-sensitive) if stored; plant immediately after extraction from fruit when possible
Sources: Research from Sugahara and Takaki (2004), Seed Therapy, Gaea's Blessing Seeds, Huertas Urbanas, VIRIAR, Gardening Know How, and peer-reviewed studies on Psidium germination ecology
