Background: Why all this fruit?
Every time we visit the grocery store we pass by shelves loaded with fruit from trees without considering why a tree bothered to produce that fruit. It is not by chance that many trees bear fruit. Fruit takes a tremendous amount of energy to produce for an organism trying to survive in a competitive world. Fruit is produced for one simple reason alone, reproduction. The plant's goal is to produce offspring.
The fruit's role in tree reproduction differs slightly from plant to plant, but generally there are two reasons for it. The first reason is to protect the seeds. Many seeds are not ready to grow the moment they leave the tree. They rely on the fruit around them to protect from drying out and exposure to extreme temperatures. The second and primary reason for fruit is transportation. Trees can not get up and walk around so they have to develop clever ways move their seeds. Fruit can act as a bribe to those who are mobile. It is a way to hire animals to do the moving for them.
Selection: Grocery Store Trees
A lot of the fruit that you find in the grocery comes from trees.
Apples, Pears, Peaches, Cherries, Nectarines, Plums, Oranges, Grapefruit, Tangerines, Lemons, Limes, Pomegranates, Apricots and others all come from trees and can all be used to grow trees. The grower should be aware that the fruit from a seedling will not be identical to the fruit that the seed came from, just as you are not identical to your parents. The grower should also be aware of the tree's natural growing climate. While some trees may require tropical conditions all year, others will need a cold season to go dormant. Do a little research on your fruit and check your hardiness zone. If you want to get serious about growing tasty fruit from seeds I suggest visiting NAFEX, The North American Fruit Explorers.
Process: Preparing the seed
I have used this method to successfully grow trees from apples, cherries, and a variety of citrus including oranges, grapefruit, limes, and clementines (most clementines are seedless, but occasionally you find one that is not). This is not the only method for growing fruit trees, nor is it ideal for all fruit types, it is simply a method that I have developed that works well for me.
Step One: Select the fruit.
Pick out a piece of fruit that is ripe but not rotten. I have had the best luck with growing organic fruit and fruit from the farmer's market, but any should work.
Step Two: Gather seeds.
Remove the seeds from the fruit. (Children should request the assistance of an adult when using a knife.) Take care not to cut through any seeds. Damaged seeds should be discarded. Don't forget to eat the fruit!
Step Three: Clean the seeds.
Using a clean towel wipe away all fruit debris and rinse thoroughly.
Step Four: Soak the seeds.
Pour a glass of warm water an allow the seeds to soak overnight. If possible place the glass somewhere that is warm but not hot. (I usually leave the glass on my desk under an incandescent lamp) This process helps to wake up the seed and alert it to changes in its environment, it also helps to soak away any remaining fruit.
Step Five: Clean the Seeds again
Remove the seeds from the glass and rinse with clean water. Cleaning the seeds is the most important step because any left over fruit will mold and destroy the seed.
Step Six: Plant the seeds and watch them grow
Plant the seeds 1/4 inch deep in clean potting soil. Keep the soil moist but not wet. Place the pot in a sunny window. If it is summer place it outside and provide shade from full midday heat. Do not let your seedlings dry out. Once they have sprouted they are very vulnerable and need time to establish their roots. A lot of the growth that is occurring at this time is below the soil, so do not try to transplant them right away. Some trees may take years before they start to produce fruit and some may never produce fruit if the conditions are not right. In the meantime learn about your plant and be patient, the reward of eating and sharing fruit grown from your own tree will be worth it in the end.
These are a few of the trees that I started last year. Right now they are over wintering under my AeroGarden lamp. Next summer I will repot them and move them out into the sun.