As the weather cools and your landscape settles into dormancy, it’s the perfect time to give your trees and shrubs a little extra protection. Spraying horticultural oil in the fall helps control overwintering insects and eggs like scale, mites, and aphids that can damage new growth in spring. This natural, easy-to-use treatment creates a barrier that smothers pests and fungal diseases without harsh chemicals, keeping your plants healthy and strong year after year. A quick fall spray now can mean fewer problems and more beautiful growth when Spring returns!
Bonide’s All Seasons Horticultural & Dormant Oil, available here at Evergreen, is an effective, natural control for many fungus, insect, and mite infestations. It works by suffocating overwintering pests and their eggs—giving your plants a clean, healthy start before spring growth begins.
Think of it like wiping down your kitchen counters before you cook—you know they’ll get messy again, but it’s always best to start fresh!
When to Spray on most Trees & Shrubs:
- Apply twice during the dormant season — between leaf drop and bud break, spacing applications about two weeks apart.
- Choose a calm, dry day when temperatures are above 40°F and will stay above freezing overnight.
- Do not spray when temperatures exceed 80°F, as the oil can damage plants in heat. Horticultural oil is thicker than neem oil, making it more effective in cooler weather—but also more likely to burn plants if applied in heat.
For Fungus- or Insect-Prone Plants
(such as Fruit Trees, Roses, Dogwoods, Lilacs, and Peonies)
Fall Steps:
- Clean up fallen leaves from infected plants. While leaf litter can be beneficial for pollinators and soil life, focus removal only around plants prone to disease. (If you compost, make sure diseased leaves are handled properly by burning or trashing instead of composting)
- Spread sulfur around the base of susceptible plants as a natural fungicide—similar to how you’d treat tomato blight.
- Clean your pruners before use.
- Prune out any diseased, crossing, or damaged branches.
- Spray horticultural oil between late fall after leaf drop and early spring before leaf bud to smother overwintering pests and fungus.
In Spring:
- Scout for recurring issues and complete any final pruning before growth begins
- Do any final pruning before Spring arrives
- Watch for fire blight on apples and pears as the weather warms.
- Spray horticultural oil before leaf bud following initial steps
This should help give your trees & shrubs a fresh start in the Spring. Additional questions? Just let us know.
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