The Lambert sweet cherry tree is a popular sweet cherry variety, cherished for its attractive fruit. Cultivated for over 150 years, especially in the Pacific Northwest, it remains a significant choice for home gardeners and commercial growers. Known for consistent production of flavorful cherries, it’s favored for fresh eating, baking, and preserving.
Lambert Sweet Cherry Characteristics
The Lambert sweet cherry tree reaches 12 to 25 feet tall with a 20-foot spread, forming an oval canopy. It exhibits vigorous growth and an upright habit, making it a robust landscape addition. Its dark green foliage turns yellow in autumn, and fragrant white flowers appear in early spring. It is suited for USDA Hardiness Zones 5-8, with good cold tolerance.
The fruit is prized for its large, dark red, heart-shaped appearance. They have a flavorful, sweet taste and a firm, juicy texture. Fruit ripens mid-July to August, making it a late-season variety. Often compared to Bing cherries in quality, some consider them second only to Bing as a commercial cultivar.
Ideal Growing Conditions and Planting
Proper site selection is key for Lambert sweet cherry trees. They require full sun (at least six to eight hours daily) for optimal fruit production and health. Sunlight also minimizes fungal problems.
Well-draining, fertile loam is the preferred soil type. While some sources suggest they are not particular about soil type, most sweet cherries thrive in slightly acidic to neutral soil (pH 6.0-7.0). Avoid heavy clay or overly sandy soils, which hinder root development and water drainage.
When planting a bare-root or containerized tree, ensure the root ball’s base is above ground level. Dig a hole wide enough for roots to spread freely. Space multiple trees 18 to 30 feet apart to allow for mature canopy size, good air circulation, and root expansion to access nutrient-rich soil.
Ongoing Care and Maintenance
Consistent watering is important, especially during dry periods and for young trees. Newly planted trees need deep watering two to three times weekly in their first year, allowing topsoil to dry slightly between waterings. Young trees need deep watering once weekly during the growing season for the initial two to three years to encourage a robust, deep root system. Established trees require watering only during prolonged dry spells, about every two to four weeks.
Fertilization supports growth and fruit production. Cherry trees are light feeders and benefit from a low-nitrogen fertilizer (e.g., 5-10-10 or 10-15-15). Over-fertilizing, especially with high-nitrogen fertilizers, promotes leafy growth at the expense of fruit and increases susceptibility to pests and diseases. A soil test can help determine specific nutrient needs before applying fertilizer.
Pruning maintains shape, promotes health, and enhances fruit production. It creates space between main branches and encourages smaller fruiting branches. Pruning also improves air circulation, preventing disease. Late winter, after the threat of extreme cold, is generally the best time for pruning.
Understanding Pollination Needs
The Lambert sweet cherry tree is self-unfruitful, requiring cross-pollination from another compatible sweet cherry variety to produce fruit. Without a suitable pollinator, fruit production will be limited or nonexistent.
Several sweet cherry varieties serve as effective cross-pollinators for Lambert. Compatible options include ‘Royal Ann’ (Napoleon), ‘Sam’, ‘Van’, ‘Rainier’, ‘Angela’, and ‘Stella’. While ‘Stella’ is self-fertile, it can still pollinate other varieties. ‘Bing’ cherry is not a compatible pollinator for Lambert.
For effective cross-pollination by bees, plant pollinator trees within 50 feet of the Lambert tree. Pollinating trees typically range from 5% to 10% of crop trees, depending on desired fruit yield.
Addressing Common Challenges
Lambert sweet cherry trees encounter pests and diseases. Common insect pests include cherry fruit fly and aphids. Monitor for these pests and employ control strategies, such as organic sprays or netting, to manage infestations.
Brown rot and powdery mildew affect cherry trees. Preventative measures include good air circulation through proper pruning and orchard sanitation. Fungicidal sprays can also be used as a preventative or treatment measure when necessary. Bacterial canker is a concern, particularly in wet or cold conditions, and is mitigated with fall and winter copper sprays.
Fruit cracking, where the cherry skin splits, often results from excessive water absorption before harvest. This occurs from heavy rainfall near ripeness or inconsistent watering after dry periods. Mitigation strategies include proper soil drainage, careful irrigation management, and in commercial settings, physical covers or cuticle protectants that coat the fruit.
A primary reason for lack of fruit production, beyond pests or diseases, is inadequate pollination. As a self-unfruitful variety, the Lambert cherry tree requires a compatible cross-pollinator nearby. Without another suitable cherry variety flowering at the same time, the tree may produce little or no fruit.