How Big Will My Apple Tree Grow?
How much space do I have? And how big will that tree get? Basic questions the backyard fruit grower should ask before planting.
First, select the right size-limiting rootstock. Here are descriptions of rootstocks available at our propagation fair. Choose accordingly.
It’s important to keep in mind it is not just the rootstock that determines how large an apple tree will grow. Each apple variety grows at its own rate. The mighty Gravenstein for instance will get more than twice as big as the meek ‘Discovery’, if planted in the same soil on the same rootstock. We refer to this basic metabolic difference in tree behavior as ‘tree vigor.’
Tree size is largely determined, then, by choice of rootstock, the vigor of the variety, spacing, training and pruning. Remember also that a tree on dwarfing rootstock does not grow to a certain size and stop. It continues to grow. What a size-controlled rootstock allows is the ability, through proper pruning and training, to maintain a tree at an appropriate size.
Here are other factors limiting the size of a tree:
- Planting close together
- Planting in poor soil
- Planting in competitive ground cover
- Limiting water and fertilizer
- Pruning to weak branches
- Pruning to wood two or more years old
- Pruning in the summer with little or no pruning in winter
- Spreading branches toward the horizontal
- Encouraging heavy early fruiting
Summer pruning and branch spreading are the preferred alternative for limiting tree size.
How far apart should I plant my apple trees?
The preferred spacing of fruit trees can be determined by:
- The rootstock
- The natural vigor of the variety
- Soil type, fertility and cropping history
- Training Method
Trees planted too close together for the variety, rootstock, or soil will compete with each other, require excessive pruning, produce lower-quality fruit, and suffer increased insect and disease-damage. Try increasing recommended spacing by an extra 2′ where soil is fertile and well-drained, but decreasing it by that much for extremely sandy or gravelly soil or hardpan. Distance between rows should never be less than the recommended in-row spacing.
To conclude, then. Tree size is determined by vigor of the variety, choice of rootstock, spacing and pruning. The variety-rootstock combinations shown will produce apple trees of the vigor and size predicted on the chart. The figures on the chart indicate recommended space between trees. Tree height, maintained by proper training and pruning, will be equivalent to the recommended in-row spacing.