Pomegranate trees are resilient plants, native to arid regions, often thriving even in less-than-ideal conditions. However, relying solely on the tree’s toughness will not yield the bountiful harvests most growers desire. To maximize the production of large, healthy fruit, you must actively support the tree’s vigorous growth cycle. Proper fertilization ensures the tree has the energy and building blocks required to transition from a healthy plant to a heavy fruit producer. Supplying nutrients at the correct time and in the right amounts significantly impacts overall tree health and the quality of your yearly harvest.
Understanding Pomegranate Nutritional Requirements
Pomegranate trees require a balanced diet of macronutrients, focusing on nitrogen (N) to support their fast-growing nature. Nitrogen is responsible for vigorous shoot growth and deep green foliage. A general, balanced slow-release fertilizer, such as a 10-10-10 or 14-14-14 N-P-K blend, is a common choice for baseline nutrition.
Phosphorus (P) is necessary for strong root establishment and is involved in flower and fruit set. Potassium (K) supports overall plant health, disease resistance, and is important for fruit quality, size, and sugar content. Mature, fruit-bearing trees benefit from a formula with a higher potassium ratio, such as a 1:1 or 1:1.5 ratio of Nitrogen to Potassium.
Pomegranates are often susceptible to deficiencies in key micronutrients, particularly iron (Fe) and zinc (Zn). Iron deficiency appears as yellowing between the veins (interveinal chlorosis) on the youngest leaves. Nitrogen deficiency, by contrast, causes a uniform yellowing across the older leaves first. Selecting a fertilizer that includes these micronutrients helps prevent these common issues.
Fertilizing Based on Tree Age and Stage
The amount and type of fertilizer a pomegranate tree needs changes as it matures, shifting focus from establishment to fruit production.
Newly Planted Trees
Avoid applying chemical fertilizer directly to a newly planted tree in its first year. The young root system is highly sensitive and can easily be damaged by fertilizer burn. Instead, focus on amending the soil with organic compost or well-rotted manure during planting. Using a layer of mulch provides a slow, gentle release of nutrients.
Young, Non-Fruiting Trees
Beginning in the second year, the focus shifts to encouraging robust structural growth through consistent nitrogen application. An initial application of approximately 2 ounces of actual nitrogen per tree in the second year is a good starting point. This amount should be increased by about one ounce each subsequent year until the tree reaches maturity. The goal is to build a strong canopy and framework to support future heavy fruit loads.
Mature, Fruiting Trees
Once the tree is five years old or older, the fertilization program must balance vegetative growth with fruit support. Mature trees need between 6 to 8 ounces of actual nitrogen annually. Growers should transition to a fertilizer where the nitrogen and potassium numbers are equal to promote flower and fruit development. Over-fertilizing with nitrogen on a mature tree can lead to lush foliage at the expense of fruit set.
Seasonal Timing and Proper Application
The timing of fertilizer application is important for maximum effect. The primary feeding should occur in late winter or early spring, just before the tree begins new seasonal growth. This provides the necessary nutrients for the spring flush of leaves and the subsequent flowering period.
A second, lighter application can be beneficial in mid-summer or after harvest, but it is not always necessary. Stop all fertilization by late summer or early fall, generally before August, to prevent stimulating new, tender growth vulnerable to winter frost damage.
When applying granular fertilizer, spread it evenly across the soil surface, starting a few inches away from the trunk and extending out to the drip line. The drip line is the area beneath the outermost branches where the majority of the feeder roots are located. Water the tree thoroughly both before and immediately after application. This prevents chemical root burn and helps nutrients dissolve into the root zone for absorption.