If your idea of growing fruit trees organically assumes a ‘no-spray’ practice, it won’t take long to figure out you’re creating a safe haven and breeding ground for overwintering pests and their eggs, disease and fungi. …and very little edible fruit.
Spraying fruit trees is common practice for the majority of commercial growers with most organic tree fruit producers spraying more than a dozen times during the growing season. The difference is that they use solely natural compounds and botanical insecticides instead of conventional synthetic pesticides, though both have their benefits.
Judicious applications of low-toxicity dormant oils and other sprays is usually the missing link in producing high quality, highly edible fruit. Other factors include choosing disease and pest-resistant varieties and/or species, proper siting, planting, feeding, pollination, pruning and regular removal of weeds, spent fruit and debris.
Dormant oil: Controls aphids, scale, spider mites and many other insects by desiccating or smothering eggs and larvae. Apply in early to mid-March, just before the tree begins to emerge from dormancy. Suggestion: Bonide All Seasons Horticultural Oil Spray.
Lime-sulfur: Controls fungal and bacterial diseases such as peach leaf curl, pseudomona and scab. It’s very important not to apply sulfur sprays to apricots.
Pesticides, sometimes included with lime-sulfur application, may include Bonide Captain Jack’s Deadbug Brew or Fruit Nut & Orchard Spray.
Fixed copper: Controls canker on apples, pears, cherries, peaches and plums. Add a spreader-sticker product to help copper adhere to the tree surface. Suggestions: Bonide Copper Dust/Spray Bonide Copper Fungicide and Monterey Liqui-Cop.
Latex paint: Coat the trunks of young trees with white exterior latex paint diluted in half with water. The paint reflects strong sunlight and prevents sunburn and winter burn that can cause tissue damage and lead to cracks, a favorite place for pests to overwinter and cause substantial winter damage.
- The best time to spray is in late winter or early spring on a windless day when the tree itself is dry and the weather is expected to be fine the next couple of days.
- Avoid spraying dormant oil when temperatures are below 40 degrees F.
- In all but a few cases never spray when blossoms are open and pollinators about. No pollinators, no fruit.
- Follow manufacturer’s instructions to a ‘T’ and mix solutions thoroughly.
- Make sure the application covers the entire surface of the trunk, branches and leaves (including undersides).
- No tree should receive dormant season treatment within 30 days of an application of sulfur fungicide or during periods of water stress. Allow two weeks between applications of copper and any sprays containing sulfur.
- Citrus fruits and avocado do not go into a dormant state and can be harmed by dormant spray.
Remember, each type of fruit has different needs and susceptibilities; we’re happy to advise you on creating a good spray regime so you’re ready ahead of time. Periods for various applications may include leaf fall, dormancy, bud appearance, bud swelling and just after petal drop. Evergreen Nursery has the right products and advice to help make spraying time a breeze!