CO-Horts

CO-Horts

Thursday, March 2, 2017

After Care of Your Grafted Apple Tree

Posted by: Curtis Utley, Jefferson County Extension

If you are planning on attending my annual Apple Grafting Workshop April 5, 6, 7, or 8 you will produce an apple tree that you can then take home and plant. You may be very nervous about how best to care for the tree you have invested so much time and (possibly) blood into grafting.
If you have not registered yet do so at http://jeffcohort.eventbrite.com

Bench grafted trees are produced in the dormant season so for the tree to survive it will need to break dormancy, reorganize the vascular tissue at the graft union and begin producing leaves to manufacture carbohydrates to perpetuate life. Deciduous trees store carbohydrates in root and stem tissue in the autumn to provide the required energy to break bud and re-leaf the following spring; liken this to fat reserves for the winter survival of a hibernating bear. Dwarfing rootstocks used for grafting ironically do not necessarily have copious amounts of roots and to add insult to injury much of the stem tissue storing carbohydrates is removed when the cuts are made for the graft union. What is left is a tree that has just enough stored energy to break bud and repair the vascular tissues at the graft union once. With this in mind what care should you provide to your new tree?
Marrying scion to rootstock in a whip graft. The ties that bind; rubber.

1.    Plant the grafted tree as soon as possible either in the ground or in a container, size #5 or larger.
A planting hole

a.    If you plant your tree in the ground be sure to set an 8-foot-tall permanent post next to the tree before backfilling the planting hole; making sure not to damage the tree’s roots.
A permanent stake should be set the day of planting

2.    Water the tree well to allow the soil to settle around the frail root system and force out large air pockets.
3.    As the leaves emerge, begin foliar feeding the grafted tree with a diluted water-soluble liquid fertilizer once per week until August first . Take note, leaves from the rootstock will emerge before any signs of life occur from the (scion) grafted wood.
Bud break of grafted apple tree

4.    Never allow the rootstock’s leafy side branches to grow taller than the grafted scion wood. If these lower shoots threaten the dominance of the grafted wood, pinch them back one inch. The rootstock leaves are temporary and will provide carbohydrates to promote root growth and callus growth at the graft union.
5.    If you have not seen life from the grafted wood 8 weeks after grafting, the graft union did not take and the scion wood has died.
6.    July first carefully remove the rubber band and wax wraps from the graft union to prevent compression injury of the graft union tissue.
Remove rubber ties by July 1

Successful graft union of a whip graft
7.    The following March prune back the scion to 2 buds. This forces all the stored energy from the roots to be channeled to a single bud that will quickly grow into a strong trunk. The second (lower) bud is your insurance policy in case the top bud is damaged.
8.    When the top bud begins growing rub out the lower "insurance policy" bud.

9.    Success! Begin training your tree into the growing system of your choice.
Apple tree trained as an Espalier, Denver Botanic Gardens

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