Will Fertilizer Help an Oak Tree Produce Acorns?

Research

• Controversies exist on whether fertilizing oak trees can lead to more and, perhaps, sweeter acorns, notes the University of Tennessee, but there is no data available to support a positive claim. Drought, frosts, insect infestations, disease and inadequate pollination may lead to fewer acorns, whether or not the tree is fertilized. Oak species typically adapt to the soil of their environment; so trees receiving more water and nutrients may produce more acorns than trees in limited spaces.

Fertilizing Oak Trees

• Growing environments and pH levels vary; test the soil prior to fertilizing oak trees. Fertilizing mature oaks that have produced solid acorns in the past may or may not affect the number of seeds or growth rate. However, using slow-release fertilizers on young seedlings keeps tender root systems from absorbing too much nitrogen. Chemical mixtures containing various amounts of nitrogen, phosphorus, potassium, calcium, magnesium and sulfur are available -- a "standard" mix of 5-10-5 NPK fertilizer is suitable for oak trees, notes the University of Texas Wildflower Center. Water the tree after fertilizing so that the granules are soaked into the ground.

Oak Trees

• Deciduous oak trees are classified by leaf shape and acorn type. The red oak group consists of trees with edged points on the lobed foliage and acorns that sprout after maturity in their second season. Leaves are elliptical and may turn orange, copper, red or brown in the fall. Red oak trees (Quercus rubra), such as those growing in USDA zones 5 through 8, prefer sandy, clay or loamy soil. White oaks (Quercus alba), in zones 5 through 9, feature leaves with rounded lobes and bear spring acorns that mature in fall of the same year. White oaks prefer acidic loamy or sandy soil and full sun to partial shade. Green leaves turn red in the fall.

Planting Acorns

• Because they take two years to mature, red oak acorns enter dormancy during cold winter months. When breaking the dormancy, a process called "stratification," you must re-create nature’s chilling requirements for red oak tree acorns to grow. Place acorns in damp plastic bags, but do not submerge the seeds in water. Refrigerating clean seeds for four to eight weeks increases their chance for germination. You can immediately replant white oak acorn seeds that have fallen to the ground.