Keys to Planting Fruit Trees
Posted: March 7, 2012
Dr. Rob Crassweller
Penn State Department of Horticulture
Countless research studies have shown that the earlier you plant fruit trees the better they will grow. Fall planting in the warmer southern regions of the U.S. allows the roots to become established before the leaves push. While this year you would have been lucky to plant trees in the fall you cannot count on having a mild fall and winter like we did. One year that I decided to plant a few trees in the fall at Rock Springs we lost 30% of them. Therefore, I normally do not recommend fall planting. However, you can take advantage of early root establishment and growth if you plant early in the spring. In looking at orchards there does not appear to be any frost in the ground so if the soil is workable and not too wet trees planted now or in the next month should benefit with increased growth. What follows are some ideas to consider when planting fruit trees.
When the trees arrive from the nursery be sure to open the boxes and inspect the trees to be sure no damage has occurred during shipment. If you plan on holding the trees in a cooler be sure that the cooler has been well aired out of any lingering gasses from storing apples in the cooler. If you do not have cooler space, heal the trees in on the shady side of a large structure.
There are two methods of planting. Large plantings are usually set out utilizing tree planters while the smaller plantings or replacement trees usually are planted using an auger. Regardless of the method it is best to transport the trees to the field in large trash cans or 55 gallon drums filled halfway with water. When taking the trees from the drum, cut any broken or extremely long roots with a good set of sharp shears. You do not want long roots that might twine around the tree, as girdling of the roots could occur as the tree matures.
Auger Method: Since most of my plantings are either mixed rootstock plantings or small size I am most familiar with this process. Typically we utilize at a minimum an 18 inch diameter auger but prefer to utilize a 24 inch auger. We normally lay out our orchards at right angles and insert a small garden stake at the site where we want the tree to be located. The stakes are set the day before and the auger operator can begin immediately and stay ahead of the planting crew. Having the auger mounted in the front on a skid loader works best to allow the auger to go ahead of the crew.
When augering the hole we will have another person checking to make sure the sides of the holes do not develop a glazed skin. This glazing can act as an artificial barrier to root penetration as the tree roots grow, resulting in a pot-bound tree. If glazing is observed then the worker should score the side of the hole with a shovel. Depending upon the number of people working in the planting crew we will have one or two individuals lay the trees into the pre-dug holes and an equal number of team(s) composed of two workers to fill in the holes and plant the tree. Be sure that those workers laying out the trees do not get too far ahead of those planting the trees so that tree roots are exposed to the least amount of sun and drying conditions. Trees are set in the center of the hole and soil is shoveled back into the hole. It is important to check to make sure the graft union is 2 to 4 inches above the surrounding ground level. (Note that for every inch the union is out of the soil it gives approximately 10% greater dwarfing.) Recommendations for planting Tall Spindle trees favor a minimum of 4 inches between the bottom of the graft union and the final soil line.
After the hole has been filled halfway with soil we go back and tamp the soil down around the roots. Then continue to backfill in the soil and then tamp when the final soil is added. If the tree is planted too deep it is simple to gently pull up on the tree with a gentle tugging motion until the graft union is at the proper height.
Tree Planter Method: This is the method most large commercial growers utilize. Although I heard one commercial grower blame the over production of fruit on the fact that you can plant so many more fruit trees in a single day with a tree planter, this is probably the easiest method to plant trees. There are two major checkpoints in this system: 1) Make sure the union is set at the proper height. This is usually accomplished by having someone go along behind the planter and pull or push down the tree. Placing the tree at the proper point on the planter may take some skill and practice on the part of the worker. 2) Make sure the tree roots do not dry out. Carry only enough trees that when you plant the last tree the roots still have some moisture.
After Care: Regardless of the method you utilize, the sooner you can get moisture to the tree the better. Planting just before rain is best. Do Not place any fertilizer in the hole or plow line. Fertilizers are salts and salts can burn young emerging roots. Wait until the ground has firmed and there are no cracks in the soil before applying fertilizer. As a final reminder, the earlier you can plant trees the better will be the subsequent growth.