Our previous posts have had numerous references made to “rootstocks.” What is rootstock and what role does rootstock play in an orchard planting?
Rootstock is basically what is underneath the ground or the roots of the tree. It is the part of the apple tree that is below the grafted scion. The rootstock works its way into the soil and sends nutrients to the rest of the tree encouraging growth and fruit development. There are many varieties of rootstock available to growers, some more vigorous than others. The type of rootstock determines the actual size of the apple tree. Besides size, rootstocks also determine how soon a tree will produce fruit. Apples have a greater variety of rootstocks than other fruits. Most types of rootstocks available, but not all, were developed at research centers and universities. Rootstocks are identified by a code of letters and numbers.
A general guideline for plantings of trees are standard, semi-dwarf and dwarf. Standard trees have a strong, deep root system and grow very tall, about twenty-five (25) feet. They grow seven (7) or more years before they produce fruit. Semi-dwarf trees are more commonly used for backyards and commercial plantings. This type of tree varies in height from fifty (50) percent to seventy-five (75) percent of the standard tree, usually fifteen (15) feet. Dwarf trees can be used for landscaping purposes as well as fruit production. This type of tree grows to about ten (10) feet but need special attention to promote proper growth and fruit production.
Our orchard has plantings of various types of rootstocks. Over the years we have been satisfied with some types more than others. It would be advantageous for us as a grower, if we could predetermine what rootstock would grow best in what area of the orchard. However, it is a “trial and error” process as the topography in our orchard varies considerably. This is just one of the challenges of growing fruit, nothing is the same and we learn something new every day.
Our next post will be a further explanation of the “standard” apple tree. We continue to move forward with the winter pruning and look forward to attending the Horticultural Show in Indianapolis where we exchange ideas and learn new growing practices.