The apricot tree (Prunus armeniaca) is a prized fruit tree known for its early spring blossoms and sweet summer fruit. While highly productive, its ultimate size is not fixed and can vary dramatically, which is a significant consideration for gardeners. The final mature height is determined by a combination of its inherent genetic makeup, the environment in which it grows, and human intervention through maintenance. Understanding these factors is necessary for managing the tree’s growth, especially when planning a home orchard where space is limited.
Typical Mature Height and Growth Rate
A standard apricot tree, grown without specialized dwarfing rootstock or aggressive pruning, typically reaches a mature height between 15 and 25 feet. These trees develop a wide, spreading canopy, often matching their height in width, which requires substantial space in a garden setting. The growth rate of a young apricot tree is relatively fast, often beginning to bear fruit within three to five years after planting. It usually stabilizes in size after 10 to 15 years in favorable conditions. During the early years, a healthy young tree should produce new shoot growth measuring between 10 and 20 inches annually, slowing to 8 to 10 inches per year as the tree matures and focuses energy on fruit production.
Varietal Influence on Final Size
Standard Rootstocks
The most significant factor determining an apricot tree’s ultimate stature is its rootstock, the root system onto which the fruiting variety is grafted. Standard trees are often grafted onto vigorous rootstocks, such as Myrobalan 29C or Marianna GF 8-1. These robust root systems promote maximum canopy development and support the tree’s natural, full-sized growth.
Semi-Dwarf Options
To achieve a smaller tree, growers select semi-dwarf rootstocks, like Krymsk 1 or St Julien, which restrict the water and nutrients absorbed by the scion. A tree on a semi-dwarf rootstock typically reaches 50 to 70 percent of a standard tree’s height, maturing between 10 and 15 feet. This genetic manipulation allows for the cultivation of full-sized fruit on a smaller plant, making it a common choice for smaller home orchards.
Environmental Factors Affecting Tree Stature
Sunlight and Soil Requirements
Even with ideal genetics, the tree’s maximum height can be limited by external environmental conditions. Apricot trees require a location that provides at least eight hours of direct sunlight daily to fuel the vigorous growth needed for height. Insufficient sunlight results in a leggy, less dense canopy and a reduced overall height. Soil quality is also important, necessitating a well-drained medium with a slightly acidic to neutral pH, ideally between 6.0 and 7.5.
Water Management
Cold, compacted soil delays root activity in the spring, stunting development and diminishing the tree’s ability to reach its full size potential. Consistent moisture is needed for growth, but excessive water can be detrimental, causing root problems that restrict canopy development.
Managing Tree Height Through Pruning and Training
Dormant and Summer Pruning
Active management techniques are used to keep standard trees at a manageable size for easier maintenance and harvesting. Pruning to control vertical growth is best performed during the dormant period in late winter or early spring before bud break. This practice, known as heading cuts, shortens the main branches to stimulate lateral branching rather than upward growth. Summer pruning, done after harvest, removes excessive vegetative growth and slows the tree’s vigor, often aiming to maintain a height of 7 to 9 feet.
Training Systems
Training systems, such as the open-center or “V” shape, are also utilized to spread the canopy horizontally. This technique naturally limits vertical height and promotes better light penetration throughout the tree, which is beneficial for fruit production.