Using Lime Sulphur in Gardens: When and How to Use Lime Sulphur
Mushrooms happen. Even the most experienced and dedicated gardeners will one day be confronted with plant fungal diseases. Fungi can affect plants in any climate and growing season because, like plants, some fungus spores thrive best in different climates. Even new disease-resistant varieties can suffer from these problems. As gardeners, we can choose to spend a fortune on different chemicals that may have residual effects to treat different symptoms, or we can use a natural-based product that has been used by growers and breeders for hundreds of years. Read on to learn how to use lime sulphur in gardens.
What is sulphur in lime?
Lime sulphur is a mixture of calcium hydroxide and sulphur. In inactive horticultural sprays, lime sulphur is usually mixed with an oil, such as mineral oil, to make it adhere to plant surfaces. These horticultural oil sprays contain a high concentration of lime sulfur that is safe only for inactive plants because the sulfur can burn leaf tissue.
Lime sulphur can also be mixed with water, at a much lower concentration, for use when plants have no leaves. Even at low concentrations and diluted with water, it is important not to spray lime sulphur on plants on hot, sunny days, as the sulphur can cause sunburn on the plants.
With such warnings, you may wonder if the sulphur in the lime is safe. When used properly, the sulfur in lime is a safe and effective treatment for fungal diseases such as
- Powdery mildew
- Anthracnose
- Black Dot
- Burn
- Black Rot
As an inactive horticultural product, lime sulphur can be used safely, even on fruits that contain it:
- Raspberries
- Blackberries
- Blueberries
- Apples
- Peaches
- Pears
- Plums
- Cherries
Lime sulphur is also used to treat fungal diseases of ornamental plants such as :
- Roses
- Dogwoods
- Brand new
- Phlox
- Rudbeckia
In addition, lime sulphur can be an effective treatment for certain pests.
How and how to use lime sulphur
Fungal disease spores can overwinter in cracks and crevices in plants or in soil and garden debris. For this reason, lime sulphur is used in high concentrates mixed with oil as an inactive horticultural spray. The time to use lime sulphur in this way is in late winter or early spring, before the plant begins to germinate. It is also a good idea to spray the soil around plants that have been previously infected or are prone to infection.
For perennial plants or plants showing new signs of fungal disease, lime sulphur can be mixed with water and sprayed on plants at any time except on hot, sunny days. The mixing ratio is 1 teaspoon per gallon of water. Spray all plant surfaces thoroughly. Let the mixture stand on the plants for 15-20 minutes. Then rinse the plants well with clean water.
From time to time, you will notice the underside of tree trunks covered with white latex paint. Sometimes it contains a mixture of sulphur and diluted lime.
