Cherry Tree Fertilization

Fertilizing sweet cherry trees is essential to maintaining their health and productivity. Proper fertilization ensures the trees receive the nutrients necessary for growth, fruit development, and overall vigor. The fertilization process involves understanding when and how to apply nutrients, particularly for young and mature trees, and recognizing the role of essential nutrients in cherry tree development.

It is essential to perform a soil analysis before any fertilizer application. Every field has different needs, so you need to study soil and leaf analysis of your orchard before deciding on fertilization methods. However, we will list some fertilization methods commonly used in commercial cherry farming.

Essential Nutrients for Cherry Trees

The first step to fertilizing sweet cherry trees effectively is understanding the nutrients they require for healthy growth and fruit production.

Nitrogen (N): Nitrogen is crucial for vegetative growth, influencing leaf development and overall tree vigor. However, excessive nitrogen can lead to excessive leafy growth at the expense of fruit production.
Phosphorus (P): Phosphorus plays a vital role in root development, energy transfer within the plant, fruit set, and early growth. It's essential for young trees establishing their root system.
Potassium (K): Potassium helps regulate water movement within the plant and is essential for fruit quality and resistance to diseases. It enhances the size, color, and taste of the fruit. Sweet cherry trees tend to be deficient in potassium.
Magnesium (Mg): Magnesium is another element often deficient in sweet cherry trees. It plays a role in chlorophyll production, photosynthesis, and fruit quality. Deficiency can lead to interveinal chlorosis, where the leaves turn yellow but the veins remain green.
Calcium (Ca): Calcium is important for cell wall structure and helps prevent disorders such as fruit cracking and blossom end rot.
Boron (B): Boron is required in small amounts but is crucial for cell wall formation, seed development, and overall tree health.
Other micronutrients such as Iron (Fe), Manganese (Mn), and Zinc (Zn) are often applied as foliar sprays or soil amendments when deficiencies are identified through testing.

Fertilization Schedule for Different Age Groups

Cherry trees are generally “light eaters” (especially sour cherries) and do not require heavy fertilization. Experienced cherry growers claim that cherry trees need one fertilizer application every spring (usually in the first four years of development) until they become resilient enough. Then, we may apply another fertilization after harvesting. In soils with low pH (5 or lower), the farmer may expect to have some calcium (Ca) and magnesium (Mg) deficiencies or/and reduced availability of nitrogen (N), phosphorus (P), and potassium (K). If the problem is significant, the grower should consider taking actions to neutralize/increase the pH over time by adding lime.

Choosing the Right Fertilizer and Application Techniques

Depending on their needs and their orchards, farmers may choose to apply a combination of different types of fertilizers at different times of the year to best meet the trees' nutrient needs. As a result, a combination of granular and soluble/liquid fertilizers may be used.

Granular fertilizers are a common choice for cherry trees due to their ease of application and ability to slowly release nutrients over time. These complete fertilizers offer the 3 main nutrients (N-P-K) early in the season as a basic fertilization applied in the soil. The fertilizers can be broadcasted close to the active root zone of each tree. After the application, the fertilizer must be incorporated into the soil to enhance nutrient absorption and reduce the risk of runoff. This can happen using machinery (tiller) or irrigation (or rainfalls).

Liquid fertilizers provide a quick option for nutrient supply and are often used for foliar applications (spraying) or through fertigation. Foliar fertilization can address nutrient deficiency quickly and efficiently and immediately supply the plants with nutrients. They can be used during the growing season when nutrient uptake is high.

Depending on the soil’s nutrient profile, it may be necessary to add compost or well-rotted manure to the orchard before establishing the young trees or before the growing season to help improve soil health and fertility. They are usually combined with complementary applications during the season to support a good growth and yield. Under certain circumstances (well-drained, fertile soil), fertilizer application may not be required.

Tip:

As a rule of thumb, if the shoots of a young non-bearing cherry tree grow 15 inches (38 cm) or more within a year, then we do not need to fertilize. Similarly, the shoot elongation should be 8 inches (20 cm) or more for productive-mature trees. However, if we notice that trees are not growing properly and their leaf growth is slowed down (during the first year), we may add a nitrogen-rich fertilizer in the following year (¼ to ⅓ pound or 0.11-0.15 kg of actual nitrogen per tree). The amount of this application depends on how many years the trees are established in the orchard. Typically, ⅛ lbs (0.055 g) of fertilizers is usually required for each year of the tree age.

When and How to Apply Fertilizer

Fertilization Schedule for Young and Mature Cherry Trees

Young Trees (Years 1-4): For young trees, the focus should be on establishing a strong root system and moderate vegetative growth. Apply moderate and conscious fertilization to young trees as they are sensitive to toxicity. Wait until the trees begin bearing fruit, typically around 4-7 years old.

Some growers apply a balanced fertilizer consisting of essential nutrients, such as nitrogen (N), potassium (K), and phosphorus (P), in the first two years, usually in the form of granules. You can apply granular fertilizers in early spring before bud break and after harvest. This timing allows nutrients to be available during critical growth and fruiting stages. We can apply these granules to the soil at the rate of 10-10-10, 5-10-10 N-P-K. When growing sweet cherry trees, these rates can be 15-15-15 or 10-15-15 N-P-K.

In the third year, growers may spray liquid fertilizers. Finally, growers can apply soluble fertilizers in the fourth year, generally at the rate of 20-20-20 N-P-K.

Mature Trees (Years 5+): Mature cherry trees have different fertilization needs compared to younger trees. The focus shifts from establishing growth to maintaining productivity and fruit quality.

The basic application takes place in early spring, 2-3 weeks before flowering starts (bud break). This timing ensures the trees have sufficient nutrients for flowering and fruit set. In very poor soils and super-high-density orchards, one or more complementary fertilizations may be needed. In cherry orchards with light to medium soils, 300-700 trees per hectare (120-280 per acre), and an expected yield of 20 MT per hectare (8 MT per acre), the base dressing recommendation is around 55 kg of N, 55 kg of P (P2O5), 88 kg of K (K2O), 44 kg of Ca (CaO) and 22 kg of Mg (MgO) (25 lb of N, 25 lb of P, 40 lb of K, 20 lb of Ca and 10 lb of Mg).

Some farmers may choose to apply fertilization both from the ground and as fertigation or foliar application. Potassium (K) is an essential nutrient for fruit growth and quality. In years with large yields (trees loaded with fruits), farmers apply multiple foliar applications of K for uniform ripening and improved fruit quality. Experience farmers say they may perform up to 5 applications with K from flowering to fruit maturation.

In some cases, cherry growers may apply/spray with boron at the start of flowering. Moreover, in cases of N and K deficiencies, foliar fertilization (spraying) can be applied in early fall while the tree foliage is still green and active. Be careful and use the fertilizers in a circle at least 18 inches from the tree trunk. In deficient soils or in years of large production, a complementary postharvest application may be needed to help the plants replenish nutrients used during the fruiting process and prepare them for the following season.

Note!

However, these are just standard practices that should not be followed without doing your own research. Every field is different and has different needs. Checking the soil nutrients and pH is crucial before any fertilizer application. Leaf analysis is very important for identifying and correcting nutrient deficiencies in cherry trees. You can always seek advice from a licensed agronomist.

Regular monitoring of soil and tree health is essential for effective fertilization. Conduct soil tests every few years to assess nutrient levels and pH and adjust fertilization practices accordingly. Leaf tissue analysis can also provide valuable information on nutrient uptake and help identify deficiencies before they impact tree health and productivity.

Additionally, observe tree growth and fruit quality to fine-tune fertilization practices. Adjust the timing and amount of fertilizer applied based on tree response and avoid over-fertilization, which can lead to nutrient imbalances and environmental pollution.

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