Gardening Articles: Care :: Pests & Problems
Growing Organic Apples (page 3 of 4)
by Michael Phillips
Tools and Supplies
Decide on your strategy and gather your materials while trees are still dormant. Most likely you'll include a sulfur-containing spray or dust, a sticker-spreader, especially if you live in a rainy area, traps for codling moth and apple maggot, and maybe a Bt spray to aid control of codling moth. You'll also need a spray applicator. How much to invest in a sprayer depends on your commitment. I recommend the Solo backpack sprayer ($100), especially with the 60-inch brass extension or 20-inch plastic extension to help reach into tall trees. Less expensive sprayers can serve nearly as well. All of these supplies are available from a variety of catalog suppliers.
The Seasons of an Apple Tree
Exactly when and how fast your apple tree progresses from dormancy through bloom depends upon your climate and the weather. But to track that progress, apple growers long ago identified and named specific stages of spring growth. Those stages for the tree are then linked to the various pests that prey on apple trees and fruits. By observing the stage of the tree, you can know the stage of the pest. I've included approximate dates for where I live, in USDA Hardiness Zone 4, to give you an idea of timing.
Dormant: November through March
- In fall, rake and clean below your tree to minimize overwintering scab disease. Or scatter ground limestone over the leaves to hinder scab reproduction and to maintain optimum soil pH.
- Prune your tree in March, while still dormant and shortly before spring growth begins. Prune to open the tree to air and light, a key to disease prevention. Remove prunings from garden area to prevent rot spores from establishing on cut branches.
- Order supplies for the coming season. More often than not, organic alternatives are available only from mail-order sources.
Green or Silver Tip: Early April
- Spread compost 1- to 2-inches thick under dripline of each tree. Apply gypsum if fall soil testing indicated calcium levels are moderate to low.
Quarter-Inch Green: Mid-April
- Apply an organic fertilizer blend, such as a 5-3-4.
- Cultivate a circle several feet in diameter around newly planted trees the first several years as well.
Pink Bud: Late April
- Now begins primary scab season. Apply liquid sulfur with sticker-spreader NuFilm 17 before next predicted rain.
- Spray sulfur now and 10 days later to minimize cedar-apple rust and powdery mildew.
Petal fall: Late May
- Apply repellent spray now and again in a week to help fend off curculio invasion.
- Primary scab season usually ends with a daytime rain soon after petal fall. Be sure to have fresh sulfur spray in place before this rain if more than a week has passed since the previous sulfur spray. Repeat sulfur spray 10 days later to control powdery mildew and cedar-apple rust.
- Place drop cloths under trees to collect and destroy "June drops" infested by curculio.
- Hang codling moth traps and lures.
- Spray Bt for first-generation codling moth approximately two weeks after petal fall. Repeat every 3 to 5 days at twilight over a two-week period.