Cherry trees can be grown in Illinois, but success requires informed selections and careful management practices. The state’s varied climate, including challenging winter cold and humid summers, means growers must choose cultivars specifically adapted to the region. This approach ensures the fruit trees can thrive and produce a reliable harvest.
Climate Suitability and Hardiness Zones
Successfully growing cherries in Illinois requires understanding the state’s USDA Hardiness Zones, which range from 5a in the north to 7a in the far south. This range dictates the cold tolerance a tree must possess to survive the winter. Sudden temperature swings, especially late spring freezes after a warm spell, pose a significant threat by damaging emerging flower buds.
Cherry varieties are divided into two groups based on cold tolerance. Sweet cherries (Prunus avium) are less hardy and are generally limited to the milder central and southern parts of the state (Zones 6 and 7). Tart or sour cherries (Prunus cerasus) are considerably more cold-tolerant, with many cultivars thriving across all of Illinois, including the colder Zone 5 regions.
Selecting the Right Cherry Varieties
Tart cherry varieties are the most reliable choice for consistent results across the entire state. These trees are valued for their superior cold hardiness and self-pollinating nature, meaning a single tree can produce fruit without a second variety nearby. Highly recommended cultivars include ‘Montmorency,’ the industry standard, and ‘North Star,’ a naturally dwarf, cold-tolerant variety. Other excellent self-fruitful options include ‘Meteor’ and ‘Suda Hardy,’ which are suitable for northern Illinois gardens.
Sweet cherries require a more strategic approach and are best suited for Central and Southern Illinois. Most sweet cherry cultivars are self-unfruitful and require a second, different variety that blooms simultaneously for cross-pollination. Notable sweet cherry varieties that perform well include ‘Black Tartarian,’ ‘Ranier,’ and ‘Van’. ‘Stella’ is a unique exception, as it is one of the few sweet cherry cultivars known to be self-fruitful.
The tree’s rootstock also plays a significant role in its regional success and size. Sweet cherries are often grafted onto Mazzard or the newer dwarfing Gisela rootstocks, while sour cherries frequently use Mahaleb or Gisela. Choosing a tree on a dwarfing rootstock allows for easier management and protection in challenging climates.
Essential Planting and Care Requirements
Correct site selection is important for cherry tree longevity, as these trees are intolerant of poor drainage and shade. They must be planted in a location that receives a minimum of six hours of direct sunlight daily and offers excellent air circulation. Good air movement helps dry foliage quickly, reducing the incidence of fungal diseases that thrive in Illinois’ humid summers.
The soil must be deep and well-drained, as cherry trees are susceptible to root rot if the roots stay wet for extended periods. The ideal soil pH level for cherry trees falls between 6.0 and 7.0. Before planting, prepare the site by digging a wide hole to accommodate the root system. The tree should be set about one inch deeper than it was in the nursery container.
New trees should be watered regularly until established. Apply a layer of organic mulch around the trunk to conserve soil moisture and suppress weeds. Pruning is a yearly requirement that maintains tree health and encourages new fruiting wood. Pruning should be conducted during the late winter dormant season or in the dry summer months. Pruning during dry periods minimizes the risk of pathogens entering the fresh wounds, particularly Bacterial Canker.
Managing Regional Pests and Diseases
Cherry trees in Illinois are susceptible to several biological threats common in the humid Midwest environment. The most prevalent disease is Cherry Leaf Spot, a fungal infection that causes small dark spots on leaves, leading to yellowing and premature leaf drop. This defoliation weakens the tree and reduces its winter hardiness, making preventative fungicide applications a common practice for sour cherries.
Brown Rot is a serious fungal issue, particularly affecting the fruit and blossoms during warm, wet spring weather. Symptoms include withered blossoms and a brown, velvety mold on the ripening fruit. Managing Brown Rot requires maintaining tree sanitation by removing infected fruit and practicing timely protective fungicide sprays.
Bacterial Canker, caused by Pseudomonas syringae, is a concern in cold climates. It appears as sunken, dead areas on the bark that may ooze a gummy substance. This disease often enters the tree through cold-damaged tissue or pruning wounds. Pests like the Cherry Fruit Fly, whose larvae tunnel through the fruit, and various boring insects also require vigilance and targeted management to protect the crop.