The Guava is a perennial tropical and a member of the Myrtle family. Because the guava is a tropical, it is only viable in planting zones 9 and up. The tree does well in most any kind of soil from heavy clay to light sand. It tolerates a wide range of pH levels from 4.5 to 9.4, though a pH between 5.5 and 7 is ideal. While good-draining soil is generally recommended to grow guavas, they have been known to grow well in wet areas where most other fruit trees would perish. This tree will thrive when planted in a sunny spot.
Place your guava seed on a wet paper towel and fold the paper towel over the seed. Place the paper towel into a sealable plastic bag. Poke holes into the baggie with a toothpick.
Take a plate and add a bit of water to it. Place the baggie on top of the plate. Set the plate in a dark place and wait three weeks. Add water to the plate every four to five days. Allowing the seed to remain moist while in a dark place will help to speed along germination.
Prepare a soil mixture in a gallon bucket that is one part compost and two parts potting soil.
Remove the seed from the baggie and the paper towel. Bury the seed 2 inches deep in the center of the bucket.
Water the soil and then cover it with plastic wrap. Poke ten to twelve holes into the plastic wrap. Place the bucket in a sunny location.
Remove the plastic wrap from the container when your guava seedling appears. Keep the soil moist. Allow the seedling to grow in the bucket until it's roughly 18 to 24 inches tall.
Dig a hole for your guava tree. The hole should be deep enough to completely cover the roots of the young sapling. Gently tamp down the soil around the tree after it's planted to remove any air pockets which may be around the tree's roots.
Water the tree thoroughly. The tree will require between 40 and 80 inches of water per year to thrive. Plan to water the tree often if you are not in a rainy area.
Fertilize your guava tree monthly with a complete fertilizer mix. After the tree's first year, fertilizer applications can be reduced to every other month. Plan to spray a nutritional spray on the tree twice a year, generally in the spring and early fall. Spray should contain zinc and copper.