At least 24 primary species of pear trees (Pyrus spp.) exist, including common varieties that produce edible fruits. They include the Asian pear (Pyrus pyrifolia) and common pear (Pyrus communis). Most varieties are propagated through grafting or budding because seed-grown pear trees may not resemble their parent plants in terms of fruit production. The seed-grown trees often have enough ornamental value to make them worthwhile to start, though.
Understanding Pear Hardiness
Asian pear is hardy in U.S. Department of Agriculture plant hardiness zones 5 through 9, although some of its cultivars are more or less cold-hardy. For example, 'Ya Li' (Pyrus pyrifolia 'Ya Li') survives winters in USDA zone 4, and 'Hosui' (Pyrus pyrifolia 'Hosui') is hardy in USDA zones 6 through 9.
The common pear tree is hardy in USDA zones 4 through 8, although the popular common pear cultivar 'Bartlett' (Pyrus communis 'Bartlett') is hardy in USDA zones 5 through 7.
Gathering Pear Seeds
Ripeness matter when it comes to germinating pear seeds. Take seeds from only ripe pear fruits with solid coloring and firm flesh. Each pear fruit contains up to 10 shiny, dark-brown or black seeds. Remove the seeds from the fruits, and place the seeds in a glass of water overnight to test their viability. Sow only the seeds that sink to the bottom of the glass.
Pretreating the Seeds
Pear seeds germinate best when cleaned and chilled. Wash the seeds thoroughly in cool water, scrubbing them gently with your fingertips to remove the sugary, sticky flesh attached to them. Once the seeds are clean, wrap them in moist sphagnum moss, and stick the moss inside a sealable plastic bag. Place the plastic bag in the crisper drawer of a refrigerator for two months. Pear seeds need a two-month chill period at 40 degrees Fahrenheit, which is roughly the temperature in most refrigerators.
The sphagnum moss in the plastic bag should be checked every few days and remoistened with water from a spray bottle as often as necessary to keep the pear seeds moist.
Germinating the Seeds
After the chilling period, pear seeds are ready to sprout. They need very little coaxing to send up seedlings, although they must be sown under the right conditions.
Fill a 4-inch-pot# with soilless seed-starting mixture. Alternatively, fill the container with sand or milled peat. Moisten the growing medium with fresh, clean water, and ensure the pot has at least one drainage hole at its base to prevent rot.
Sow one pear seed in the center of the pot at a depth of 1/2 inch. Cover the seed completely with the growing medium. Dribble water into the pot to settle the medium, but don't saturate the medium because too much moisture can drown the pear seed. ((Ref 6, Page 926, "Nursery Practices", sentence 1))
Set the pot in a bright, sheltered location with direct sunlight in the morning and afternoon. Pear seeds germinate best at about 70 degrees Fahrenheit but are forgiving of cooler temperatures for short periods of time.
Keep the growing medium evenly moist. Water only when it feels barely damp just below the surface. Use a spray bottle to water to keep from dislodging the pear seed.
Watch for sprouts starting in one week. Don't be surprised, though, if it takes up to one month for seedlings to emerge. Continue watering when the medium is nearly dry beneath the surface.
Transplant the pear seedling when it produces two sets of leaves. Place it in a 1-gallon pot with multiple drainage holes in its base. Use standard potting soil with perlite mixed in. Ensure the base of the seedling stem is at the same soil depth it was in its original pot. ((professional recommendation))
Caring for Pear Seedlings
Pear seedlings need to grow in their pots for at least one year so they have time to develop strong roots before they are planted in the ground. The seedlings are fairly , but they need full sun exposure and routine watering.
Transplant each pear sapling into a sunny bed with fast-draining, moderately fertile soil in spring of the tree's second year. Wait until after all frost danger has passed and the soil has warmed and dried out. ((this section: professional recommendations/out-planting age: Ref 6, Page 926, "Nursery Practices"))