Citrus trees and other heirloom fruit trees can be started from seeds, even those left over from eaten fruit. Beware of hybrid varieties because they won't always reproduce true to type. If a tree is not a hybrid variety, start more trees from its seeds. Fruit bought at the market might not be suitable for propagating because many varieties are hybrids. Grafted fruit trees bought at a nursery produce fruit sooner than those started from seed.
Planting seeds of fruit
Gather very ripe fruit from a tree to reproduce. Cut the fruit open. Remove the seed or seeds from the center. Wash all pulpy fruit from the seeds with a small, soft brush. Place the seeds on a towel to dry.
Scatter citrus seeds on a screen propped up on boards or bricks in a dry, dark, well-ventilated area such as a garage. Leave them for one week to 10 days, then rub them between your fingers to determine if they are dry.
Put large stone fruit seeds in a plastic bag with equal amounts of peat moss, sand and vermiculite. Sprinkle the contents of the bag with about ½ cup of water. Seal the bag.
Cold stratify the seeds in a refrigerator for three or four months. Check for signs of germination every week. Remove the seeds from the refrigetator if they begin to sprout.
Plant all types of seeds in nursery flats or 1 gallon pots. Water the pots or flats well until water runs out of the drainage holes. Keep them in a sunny, warm location. Water the pots at least twice each week, keeping the soil moist at all times until growth occurs above the soil line.
Give your seedlings a dose of houseplant fertilizer when they are 3 months old and again once a month thereafter. Follow label instructions for how to apply the fertilizers.
Plant young trees in a sunny spot when they are about 1 foot tall. Dig at least a 1-gallon bucket of compost into the planting hole for every 5-gallon bucket you dig out when the final spring frost has passed.