How
to Plant Guava Seeds
Native to the tropical regions of southern Mexico
and South America, the sweet fruit of the guava tree (Psidium guajava) tempts
the taste buds whether served fresh or as a drink, dessert, or candy. Guava
trees thrive in U.S. Department of Agriculture plant hardiness zones 9b through
11, growing into small, shrubby trees suitable for container gardening.
The fruit contains several hard seeds that are viable up to one year. When
sprouting guava seeds, gardeners should be aware that the seedlings rarely grow
true to the parent plant.
Stratifying the Seeds
Whether fresh or stored for up to a year, guava
seeds require a process known as stratification to break through the hard
outer shell. While professional growers pretreat the seeds with sulfuric acid,
home gardeners should boil or soak the seeds.
Boil the Seeds
To soften the hard seed coating, bring 2 cups of water to a boil in a saucepan.
Place the guava seeds in the boiling water and boil for five minutes. Remove
the pan from the stove and allow the water and seeds to cool. Plant the seeds
immediately after they have cooled to room temperature.
Soak the Seeds
Place the guava seeds in a bowl and cover with 2 to 3 inches of warm water.
Cover the bowl and place it in a warm, dark location for two weeks. Add more
water if necessary to keep the seeds wet. After two weeks, the seed coating is
soft enough for the inner embryo to germinate.
Planting the Seeds
Put sterile seed starting mix in individual peat
pots or in a seed-starting tray. Water the mix thoroughly to ensure that
the medium is evenly moist. Plant the seeds 0.25-inch to 0.5-inch deep in the
damp seed starting mix and cover the pots or tray with a plastic cover or
plastic wrap to maintain a high humidity. Monitor the seed-starting mix and
mist with water regularly to keep the soil moist but not waterlogged.
Keep the Seeds Warm
Place the seed-starting tray in a brightly lit, warm location or on a seed
heating mat set at 80 degrees Fahrenheit. Guava seeds germinate at
temperatures between 70 degrees Fahrenheit and 85 degrees Fahrenheit. If the
soil temperature drops below 60 degrees Fahrenheit, the seeds stop growing. The
guava seeds germinate slowly, requiring between four and 12 weeks before the
tiny sprouts appear above the surface. When the seedlings appear, remove the
plastic cover to prevent damping off.
Caring for the Guava Tree
Caring for the Guava Tree
Transplant the seedlings into flowerpots when they reach 2 inches to
30 inches tall. While guava trees planted outdoors are not fussy about the soil
type, when planting in flowerpots, use a rich potting mix with a high
percentage of compost or other organic matter.
Watering and Fertilizing
Guava trees require regular watering, especially in the first weeks after
transplanting. Water twice a week with 1 inch of water, or 6 gallons of water
for every square yard of garden soil. When planted in a flowerpot or planter,
add water until it drains from the bottom of the pot. Keep the soil moist, but
not waterlogged through the growing season. When new growth appears, water
potted guava trees bi-weekly with a balanced 10-10-10 (nitrogen, phosphorus,
potassium) liquid fertilizer or an all-purpose fertilizer, such as
Miracle-Gro Water Soluble All Purpose Plant Food. Use 1/2 teaspoon of
fertilizer per 1 gallon of water for indoor plants. Fertilize immediately after
watering to avoid burning the guava tree's roots.
Producing Fruit
When placed in a warm, brightly lit location, and watered and fertilized
regularly, a guava grown from seed may produce flowers and fruit after two to
five years. Indoor plants may require hand pollination with a small paintbrush.
Honeybees generally pollinate outdoor trees.
Cautions
Guava trees cannot tolerate frost or temperatures above 115 degrees Fahrenheit.
Plant outdoor trees against sheltered east or south facing walls; west-facing
walls may be too hot in the summer. In addition, guava trees are invasive in
the subtropical and tropical climates of Florida, Puerto Rico, and Hawaii.