- Irrigate every 7 to 10 days if you have mulched your fruit trees.
- Begin pruning of older wood to improve tree structure, lower height and improve fruit production.
- Two applications of a dormant oil should be applied in winter or as late as early spring after leaf development (February) AS LONG AS THE TREES ARE NOT IN FLOWER.
- Whitewash trunk and large limbs after pruning.
- Borer control by mechanical means (sharp knife). Remove limbs if the borer damage has damaged over half of the circumference.
- Fertilize trees with a fruit tree fertilizer (usually these are high in phosphorus) as well as iron.
Whitewashing. The purpose of whitewashing is to prevent damage to the trunk and primary limbs from intense sunlight and subsequently attack from borers and entrance of disease to damaged areas. The whitewashing is done with a sprayer or with a brush.
White or light-colored latex paint is diluted at least 1:1 with water and applied to the trunk and scaffold limbs, concentrating primarily on the south and west exposures.
Much of the damage is in the primary and secondary scaffolds, on the top surface, in the interior of the canopy where the branches are exposed to the sunlight. The trunk and primary scaffolds are the main focus because they are permanent supports for the fruit-bearing branches. Fruit-bearing branches can be regenerated if damaged and removed due to borer damage.
Apply the whitewash to any newly-planted trees, and trees with the color of the bark showing. Apply the whitewash to the trunk and primary scaffold limbs that are facing south or west. Pay particular attention to the interior of the canopy and apply up the branches two inches in diameter or larger.
Controlling Borers. The best time to find borers is when the leaves are off of the trees. We usually find them on the tops or sides of branches exposed directly to sunlight where the branches can get sunburned. The damage attracts the insects through “smell”.
The damaged area is located and cut out with a knife. All of the damaged wood is removed hoping that we will see the borer so it can be removed.
If damage by the borer extends more than halfway around the branch, the branch is removed. This is why it is so important to protect the trunk and major limbs by painting them with white paint. We generally chip the wood we prune from the trees right back into the Orchard and use it for mulch. One of the big reasons we think our Orchard has been productive and healthy is because of our mulching program. Chipping the wood back into the Orchard destroys any borers that might be “hiding” in the wood.