Can Lime Sulphur Be Used With Oil Spray?

A Splash of Lime

• Lime sulfur is used to kill overwintering fungal disease on blueberries (Vaccinium cyanococcus), which can be grown in U.S. Department of Agriculture plant hardiness zones 3 through 7, blackberries (Rubus fruticosis), grown in USDA zones 5 through 1, grapes (Vitus spp.), hardy in USDA zones 2 through 10, and other small fruits as well as apple (Malus domestica), grown in USDA 3 through 8, peach (Prunus persica), hardy in USDA 5 zones through 8, and other fruit trees. Applied when trees are dormant, lime sulfur helps control peach leaf curl, plum pocket and black knot on cherry (Prunus avium), grown in USDA zones 4 through 7, and plum trees (Prunus domesticus), suited to USDA zones 2 through 9.

Mixing the Magic Potion

• Horticultural oil added to lime sulfur on dormant plants is effective against overwintering eggs of spider mites and scale. You can safely mix lime sulfur with oil when your plants are fully dormant to increase the penetration of sulfur on tissue infected with fungal spores. Mix 3 ounces of horticultural oil and 6 ounces of lime sulfur to 1 gallon of water. Apply when temperature is above freezing but your plants have yet to grow leaves.

Use on Budding Beauties

• Lime sulfur is best applied when the plant buds begin to swell but before leaves begin to grow. If you mix it with horticultural oil, lime sulfur will injure green plant tissue. If you spray lime sulfur on plants that have green tissue, do not use oil for a week. When green tissue is exposed, add 8 to 10 ounces of lime sulfur to 10 gallons of water. Apply early in the morning or late in the afternoon to avoid burning the plants and do not apply if the temperature is above 75 degrees Fahrenheit.

Words of Warning

• Applying lime sulfur during dry weather or when the temperatures reach 80 to 95 degrees Fahrenheit can damage your plants. Lime sulfur is corrosive and should not be absorbed through the skin, swallowed or inhaled. Wear protective goggles to protect your eyes.