Cherries are a beloved fruit, but the plant that produces them can be a source of confusion for many home gardeners. The simple answer is that true cherries grow on trees, not bushes. However, the modern horticultural landscape includes smaller varieties and related plants that blur this line for the casual observer.
True Cherry Trees: Sweet Versus Sour Varieties
The vast majority of commercially grown cherries belong to two distinct tree species within the Prunus genus.
Sweet Cherries (Prunus avium)
Sweet cherries, like Bing or Rainier, are typically sold fresh. These trees are the largest cultivated cherries, commonly reaching heights of 30 to 35 feet with a wide spread. Sweet cherries prefer milder climates, generally performing best in USDA hardiness zones 5 through 7.
Sour Cherries (Prunus cerasus)
Sour, or tart, cherries include varieties such as Montmorency. These trees are naturally smaller than their sweet counterparts, typically maturing to a height of about 15 to 20 feet. Sour cherries are more adaptable and cold-hardy, thriving reliably in colder regions (USDA zones 4 through 6). The fruit from these trees is often reserved for cooking applications due to its more acidic flavor profile.
The Origin of the Confusion: Dwarf and Bush-Type Cherries
The perception that cherries grow on bushes often stems from specialized growing techniques and the existence of shrub-like relatives.
Dwarf Rootstocks
In commercial and home settings, standard cherry varieties are often grafted onto dwarf rootstocks, such as Gisela 5 or Colt. This grafting process limits the tree’s overall size, resulting in a plant that may only reach 6 to 15 feet tall. These smaller trees can resemble a large shrub in a small garden space. The root system controls the canopy’s vigor and size, making the trees easier to manage and harvest.
True Bush Varieties
True shrub-like alternatives also exist, such as the Nanking Cherry (Prunus tomentosa), which is naturally a multi-stemmed, dense bush. Nanking cherries typically grow to a manageable height of 6 to 15 feet and are often used as hedges or ornamental bushes. Newer breeding efforts have introduced hybrid varieties, like the ‘Carmine Jewel,’ which are true bush cherries. These hybrids combine the fruit quality of a sour cherry with the naturally bushy, multi-stemmed growth habit of a shrub.
Cultivation Requirements for Cherry Success
Successful cherry cultivation depends heavily on meeting specific environmental needs, whether dealing with a standard tree or a dwarf plant.
Chill Hours
A key requirement is the accumulation of “chill hours,” which refers to the total number of hours the plant is exposed to temperatures between 32°F and 45°F during its winter dormancy. This period is necessary for the tree to properly break dormancy and set fruit buds in the spring. Sweet cherries generally require 700 to 800 hours, while some sour varieties can require over 1,200 hours. Without adequate chilling, the tree will experience delayed or uneven flowering, resulting in a poor fruit yield. Cherries also thrive in deep, well-drained loamy soil with a slightly acidic to neutral pH, ideally between 6.0 and 7.0.
Pollination
Pollination is another factor that dictates planting strategy. Most sweet cherry varieties are self-unfruitful, meaning they require a different, compatible cherry variety planted nearby for cross-pollination to produce fruit. Planting at least two compatible sweet cherry varieties within 50 to 100 feet of each other is necessary to ensure a successful harvest. In contrast, most sour cherry varieties, such as Montmorency, are self-fertile and can produce a full crop with only one tree.