Growing a cherry tree from cherry seeds or pit is not difficult, but if you want to grow a tree that will yield cherries, there are complications in pollinating your tree and meeting winter chill requirements. Your best bet is to plant cherry seeds from a cherry that grew on a locally grown tree or that you bought from a local fruit stand. Cherries sold in supermarkets may come from a tree that is not compatible with your climate, so avoid using those cherry seeds.
Sour cherries (Prunus cerasus), also called tart or pie cherries, grow up to 20 feet tall and will grow in U.S. Department of Agriculture plant hardiness zones 4 through 6. Sweet cherries(Prunus avium) grow 35 feet or taller in USDA zones 5 through 7 and in USDA zones 8 and 9 in the Pacific Northwest. Cherry trees need eight hours of sun a day in well-drained soil with a pH of 6.5 to 6.7.
Nurseries often sell dwarf cherry trees that are cultivars grafted onto rootstocks. The rootstock determines tree size. If you grow a tree from a pit, the tree will likely be a full-sized tree, meaning you have to give it enough space to grow. Sour cherries need 20 to 25 feet between trees. Sweet cherries need 25 to 30 feet between cherries.
You can expect to wait seven to 10 years for your tree to bear cherries. You can reduce that time by grafting your new seedling onto an existing cherry tree.
Cherry Tree Pollen Requirements
All sour cherries are self-fruitful, meaning you can grow one tree from seed and it will bear cherries, growing trees from seeds of a sweet cherry requires more effort and timing. Sweet cherries require pollen from a compatible cherry tree planted within 100 feet.
Cherry tree varieties grow blossoms, produce pollen and yield cherries at different times. If you plant the seeds of two compatible varieties of sweet cherries to pollinate one another, they have to yield pollen at the same time.
Winter Chill Requirements
Cherries grow their fruiting buds in the summer. The buds go dormant in winter and remain that way until they have accumulated enough hours below 45 degrees Fahrenheit. These are called winter chill hours.
Sweet cherries require 700 to 800 hours -- about 28 to 32 days -- of continuous exposure to temperatures of 45 degrees Fahrenheit or less. Sour cherries require more than 1,200 hours -- about 48 days -- of continuous exposure to temperatures of 45 degrees Fahrenheit or less.
If a cherry tree doesn't receive enough winter chill hours, it will develop leaves late in the spring growing season and will grow fewer buds needed for cherries the next year. They will also yield fewer cherries of poorer quality. If you get a hold of a seed late in the season, you can try freezing cherries with pits.
You will have to make sure that in order to try freezing cherries with pits by checking what type of cherries they are, and setting a refrigerator or freezer to the required 45 degrees Fahrenheit or less.
If your cherry pit comes from a low-chill variety and you live in a cold area, it will blossom early, only to have the fruit killed off by spring frosts. Freezing cherries with pits can also solve this problem if you plant the pits after the first few spring frosts come in. Try growing trees from seed with this variety by sprouting the pit indoors in a flower pot and then planting it outdoors once it is warmer outside.
Stratification and Sowing
A cherry pit is a hard shell surrounding the seed. Don't try to remove the shell to extract the seed, stratify and sow the pit.
The embryo of a new cherry tree matures inside the pit during winter dormancy, requiring a period of chilling called stratification. To grow trees from seeds through stratification, have the cherry pit outdoors when it's cold or indoors in a refrigerator.
To stratify a cherry pit outdoors, sow it in a furrow no deeper than 1 to 2 times the width of the pit. Cover the pit with soil and put 1 or 2 inches of sand over that to prevent the soil from forming a crust on the soil as winter cold stratifies the seed. Do this any time after you pick the cherry, the pit won't germinate and produce a seedling until after it has been stratified.
To prevent squirrels and chipmunks from digging up the pit, place hardware cloth or wire screen over it and push the sides and ends several inches into the soil. Remove the barrier the next spring when the new cherry plant pushes through the soil. Then keep the soil moist, but not soggy, and do not fertilize.
To stratify in a refrigerator, clean the pits of any clinging flesh and let them air dry. Put them in a glass jar or plastic container with a loose fitting lid and store them in a refrigerator for 90 to 140 days at a temperature of 33 to 50 degrees Fahrenheit. A 41-degree temperature is ideal.
In the middle of January, place the pit in moist but not wet, sand, peat moss or shredded paper towels, replace the lid and return it to the refrigerator. Remove the pit after at least 60 days. In early spring sow it in a furrow no deeper than 1 to 2 times the width of the pit. Keep the soil moist but don't let it get soggy. Do not fertilize.
Fertilizer For Growing Cherries
Many people think fertilizer always helps plants and the more fertilizer the better. That is not the case with sowing a cherry pit. The pit gives the cherry seedling the nutrients it needs to get started. Seedlings cannot handle the nitrogen in fertilizers. Give a cherry seedling at least 1 year of growth before fertilizing.
North Carolina State horticulturists recommend scattering 1/2 cup of 8-8-8 fertilizer for each yard of canopy in the cherry's second year. A second year cherry seedling will have a small spread of branches so you'll have to scale down the amount of fertilizer.