The new plant will be the same kind of plant, but its fruit and vegetative portions may not look the same as the parent, because the plant is "heterozygous." Therefore, all fruit trees must be vegetatively propagated by either grafting or budding methods.
Grafting and budding require that you have a compatible rootstock or mother plant onto which you can attach your desired variety. An inexpensive way to obtain a seedling rootstock is to collect seeds from the type of plant you are propagating.
The seeds of all common tree fruits (apple, pear, peach, and cherry) require a chilling period before they will germinate and form new plants. The chilling period occurs after the fruit portion is ripe. This period is known as either dormancy or afterripening. During this period the embryo develops until it is mature. This is accomplished by subjecting the seeds to a cold treatment.
Experimenting with Growing Fruit Trees from Seed
Homeowners and amateur fruit growers often like to experiment and grow tree fruit from seed. Frequently many of these people have the mistaken impression that a tree grown from seed will produce fruit exactly like the fruit they saw or consumed. This is an erroneous assumption because the seed is a product of the pollen (male) source and the flower ovule (female) source. The seed will produce the same kind of plant--that is an apple peach or pear. The fruit, however, will have a mixture of the two parent's characteristics. Although this may be disheartening for the person trying to preserve that favorite fruit it should be pointed out that many of our current apple cultivars were discovered as chance seedlings. Several good examples of this are Delicious, Golden Delicious, Granny Smith and McIntosh.
Another reason for growing plants from seed is to produce seedlings onto which you can vegetatively propagate a desired cultivar. Again the resulting seed will be a mixture of the parent's characteristics, and a plant selected because of its growth habit will not come true from seed. It may be more or less vigorous or more or less susceptible to pests.
In either case tree fruit can be grown from seed if handled properly. There are three basic methods that can be used. Both methods require a period of after ripening of the seed. Tree fruit seeds require a period, after the fruit is ripe, before they will germinate and form new plants. During that period the embryo of the seed develops until it is mature. The after ripening is usually accomplished by exposing the seeds to a period of cold.
Prepare a garden soil plot in the fall as you would for planting any other type of seeds. Make a furrow that is no more than 1 to 2 times deeper than the longest dimension of the seed. Cover the seeds with a light cover soil and add 1 to 2 inches of sand over the row. This will prevent crusting of the soil which inhibits germination.
Next, place a wire screen over the row. Push the edges of the screen several inches into the soil on all four sides. This prevents chipmunks and squirrels from digging up the seeds. The following spring carefully watch the seeded area closely for newly germinated seedlings. As they grow, remove the wire screen to prevent bending of the new plants.
Remove the seeds and/or pits from the fruit of which you wish to reproduce. Remove all adhering fruit portions and allow the seeds to air dry. Then place them in a glass jar to which a loosely fitted lid or cover may be added. Set the seeds aside until mid-January. Mix the seeds (in mid-January) with either moist (but not wet) sphagnum peat moss, sand or shredded paper towels. Return the mixture to the jar and replace the lid. Place the jar with the seeds in a refrigerator until after the last severe spring frosts have occurred in your area. The seeds should remain in the refrigerator for at least 60 days. In the early spring prepare a seedbed, with furrows as described above, and plant the seeds. Germination may be enhanced by soaking the seeds in water for 12 to 24 hours before planting. Keep the soil moist. Do not add fertilizer at planting.
Collect the seeds from apples that had been in cold storage for a month or so; rinse them in a 10% Clorox solution; then dust them with captan or a similar fungicide. Line the seeds out in trays of moist peat moss or vermiculite. After they germinate, plant them about 1 inch deep in parallel seed lines about 2 inches apart. After several months in a 40 degree F refrigerator the healthy seeds should germinate and sprout. Transplant them into 4 inch pots with soft tweezers, when they had 2 to 4 true leaves (not counting the cotyledons). You could also group the resultant seedlings by their probable chill unit requirements, assuming that those germinating first had lower chill requirements.
With all methods, after the seedlings are 6 to 8 inches tall carefully band 1 to 2 tablespoons of urea along each 12 inches of row. Keep the fertilizer about 2 inches away from the plants. Water thoroughly every 10 to 12 days.
Stone fruits have a hard covering over the embryo. To facilitate germination it is helpful to crack the hard covering slightly using a nutcracker just before planting. Be careful not to crush the embryo inside the covering. The new seedlings will develop a tap root. To facilitate transplanting, it is necessary to cut the taproot by pushing a spade under each plant. The spade should be pushed into the soil to cut the taproot about 5 to 6 inches below the surface.
Peach, nectarine and apricot seedlings may be budded the first summer, usually in late July or early August, and transplanted the following spring. Apple, cherries, pear and plum should be allowed to grow two years in the seedbed before budding in July or early August.
*Method 3 is courtesy of Dr. Ian Merwin, Professor Emeritus of Cornell University
|Kind||Effective Temperature ('F)||Best Temperature ('F)||Days Required|