When and What to Spray on Peach Trees
Before bud swell: Apply horticultural dormant oil or a bordeaux mixture (a mixture of water, copper sulfate, and lime) in February or March, or just before the buds swell and daytime temperatures have reached 40 to 45 F. (4-7 C.). Spraying peach trees at this time is critical in order to get the jump on fungal diseases and overwintering pests such as aphids, scale, mites, or mealybugs. Pre-bloom stage: Spray peach trees with a fungicide when buds are in tight clusters and color is barely visible. You may need to spray fungicide a second time, 10 to 14 days later. You can also apply insecticidal soap spray to control pests that feed at this stage, such as stinkbugs, aphids, and scale. Apply Spinosad, a natural bacterial insecticide, if caterpillars or peach twig borers are a problem. After most petals have dropped: (Also known as petal fall or shuck) Spray peach trees with a copper fungicide, or use a combination spray that controls both pests and diseases. Wait until at least 90 percent or more of the petals have dropped; spraying earlier may kill honeybees and other beneficial pollinators. If you use a combination spray, repeat the process after about a week. Other alternatives during this period include insecticidal soap for stinkbugs or aphids; or Bt (Bacillus thuringiensis) for caterpillars. Summer: Continue regular pest control throughout the warm days of summer. Apply Spinosad if spotted winged drosphilia is a problem. Continue with insecticidal soap, Bt, or Spinosad as described above, if necessary. Note: Apply peach tree spray in the early morning or evening, when bees and pollinators are inactive. Also, stop spraying peach trees two weeks prior to harvest. Autumn: A copper-based fungicide or bordeaux mixture applied in autumn prevents peach leaf curl, bacterial canker, and shot hole (Coryneum blight).
