By Roberta Bailey
One of the first trees I planted on my farm was a cherry tree, a ‘Bali’ sour cherry. Cherries, sweet and sour, are so beautiful; their shape; their deep wine-brown, shiny bark; their clouds of delicate pink blossoms in spring; and most of all, their fruit, pendulous red or golden jewels that are among the earliest tree fruit to ripen in the North.
Sour cherries or pie cherries (Prunus cerasus) are quite hardy (zones 4 to 7) and and can be sweet enough to eat fresh, but they develop that incredible cherry pie taste when cooked. They grown on compact trees, ranging from 10 to 15 feet tall.
Sweet cherries (Prunus avium) are sweet, low acid fruits available in the markets. They are best for fresh eating. They are less hardy (zone 5) and need a select spot in Northern climates if they are to thrive. If you can grow peaches, you can probably grow the hardiest of the sweet cherry varieties. Sweet cherry trees can get 25 to 30 feet tall, if not pruned. Dwarf varieties are available, but inquire about the hardiness and vigor of the rootstock.
Nanking cherries (Prunus tomentosa) are 6 to 10-foot spreading bushes that bear beautiful pinkish-white blossoms and good tasting scarlet fruit, best for pies and preserving. The purely ornamental flowering cherries bear no fruit.
When choosing a site, avoid cold pockets or valleys. Cherries need full sun and south-facing slopes where possible. Because of sweet cherry’s early bloom, some people plant them on a northern slope. In the North, they may need all the warmth they can get. Like peaches, sweet cherries need your best protected spot and good air drainage. Allow 12 feet for dwarf varieties; 8 feet for Nanking cherries, unless you are planning a hedge; 20 feet for sour cherries; and 25 to 40 feet for sweet varieties.
Cherries need well-drained soil with a pH between 5.5 and 8.0, ideal being 6.5. They will not thrive in cold, heavy, wet clay soils. Sour cherries tolerate heavier soils better than sweet cherries. If your soil is soggy, making a raised bed that is rich in compost is recommended. Moisture is needed at flowering and fruiting time. During droughts, apply at least 1 inch of water per week.
When purchasing a tree, look for a 1 to 2-year- old tree that is 4 to 5 feet tall. If bare-rooted, choose a tree with a well-developed root system and moderate branching. Roots are more important than branches, as the tree will spend its first year getting established and growing more roots than branches. You should prune the top to one-third of its branches to help the tree get established.
Prepare a hole that is a few feet wide and deep and loosen the soil in the bottom of the hole. Virtually all cherry trees are grafted. Set the tree in the hole so that the graft (usually a lumpy spot near base) is above ground. Begin to fill in the hole, placing the best soil in the bottom. Mix in some compost or minerals if the soil is poor. Lightly tamp the earth as you fill the hole to eliminate air holes around the roots. When the planting hole is half full of soil, add water to settle that soil around the roots. Then finish filling the hole with soil, tamping gently as you go, and add water again. To hold water better, form a ridged bowl around the tree with the soil. Water well. Young trees need an inch of water per week until fall.
Mulch helps with weed prevention, moisture retention, and the active feeding of the fine root hairs that grow close to the surface. Mulch a few feet out from the trunk, but not right up to the trunk. I use cardboard underneath the mulch to kill sod or discourage weeds. It breaks down in one year.
Cherries need some nutrition each year, unless the soil is in good condition. In spring, dress lightly with compost or manure, then mulch. Avoid too much fertility as it can lead to disease and sparse fruiting.
Cherries need less pruning than most fruit trees. When young, prune to a central leader. Cherries tend to form narrow crotches, so aggressively encourage lateral branching, even using spreaders to change the angle of branches. Narrow crotches are weak and are prone to winter cold injury. As the tree matures, you may need to go to a modified leader or open bowl to let in more air and light. For the first seven years or so, once the tree’s structure is established, you may need to do little more than prune out broken or dead limbs. As the tree comes into full fruition, you may need to thin the short blunt spurs that are the bearing wood for better fruit quality. Sweet cherries tend to have one strong branch that needs to be pruned to balance its growth with the rest of the tree. Overpruning can cause winter damage and premature aging.
Cherries bear in four to seven years, starting with light crops, then increasing to 50 to 80 pounds of fruit per tree for sour cherries and more for sweet varieties. Sweet cherries will keep refrigerated for up to three weeks. They freeze and dry well. Sour cherries are best processed immediately, though they will keep up to a week in a refrigerator. They freeze and can well, and make delicious preserves and juice – and the best pie in the world.
Birds love cherries. The best deterrent is bird netting, covering as much of the tree as you want to harvest. Scare Eye balloons, flash tape, and plastic owls have limited effectiveness. Garlic spray may lessen bird feeding. I’ve been told that the birds leave the gold cherries alone more. Mulberries that fruit at the same time as your cherries will distract the birds from your cherry crop.
Tent caterpillars can be a pest. Destroy their tent nests in the evenings when they are in them. If they have left their tents, spraying insecticidal soap or Bt is effective.
If your cherries get worms, your extension agent should be able to help you determine whether they are cherry fruit worms or cherry fruit fly larvae. Cherry fruit worms can be killed with a spray of Bt. Adult cherry fruit flies can be trapped on yellow sticky traps or red balls and pheromone lures hung in late May.
Sour cherries are self-pollinating. You need only one tree. Sour cherry varieties that do well in the North include ‘Bali’ (also called ‘Evans’), an extremely hardy (zone 2 to 3), small (10′) tree with annual crops of Morello-type fruit; ‘Meteor,’ a hardy, 12- to 15-foot tree that ripens in summer; ‘Northstar,’ a smaller, 12-foot tree that ripens red fruit in early July in Maine; and ‘Montmorency,’ a zone 3-hardy, vigorous tree with scarlet fruit.
Sweet cherries require a pollinator, except for ‘Stella’ and ‘Lapins.’ Some varieties will not pollinate each other. In Maine, it can be a challenge to find two varieties that will survive and pollinate each other. Sweet cherry varieties to try in the North include the dark red fruiting, self-pollinating ‘Stella’ (which will pollinate virtually all other varieties); disease and crack-resistant ‘Gold’ cherries; the dark-fruited, crack-resistant ‘Sam’ or ‘Van’ (also pollinating most other varieties); and black-fruited, hardy ‘Kristin.’
Whether you dream of cherry pie or sweet fruit in hand, or blossoms or feeding the birds, cherry trees require low maintenance and provide high satisfaction rates.
About the author: Roberta is a regular columnist for The MOF&G and she works for Fedco.
Damrosch, Barbara. The Garden Primer, Workman Publishing, 1988.
Fedco Trees 2002 catalog, P.O. Box 520, Waterville ME 04903-0520.
Hill, Lewis, Fruits and Berries for the Home Garden, Storey Pub., 1992.
Hill, Lewis, Pruning Simplified, Storey Pub., 1986.
Otto, Stella, The Backyard Orchardist, Ottographics, 1993.
Phillips, Michael, The Apple Grower, Chelsea Green Pub., 1998.