This artical comes in 5 parts. 1)How to use lime sulphur as a pesticide. 2) What is lime sulphur. 3)History of lime sulphur. 4) Bonsai and lime sulphur. 5) Saftey.

1) How to use Lime Sulphur
You buy it from garden centres or “got everything” stores. I bought mine from Canadian tire. It came in a two-pack with some horticultural oil.
The instructions are explicit. Mix lime sulphur 10 parts water 1 lime sulphur for dormant spray, which is what we do. If necessary, mix 100 parts water to 1 lime sulphur for spraying leafy material, like in summer.
My two-pack mixed the amounts slightly different because the combination of the horticultural oil with lime sulphur increases the potency of the mix.
Mix the ingredients into water in the applicator container.
Saturate your plant, but not to the point where the product is running off the plant. Mist so as to penetrate the cracks and crannies, these are the spots bugs hide. Feel free to cover the soil and the roots to protect them from run-off.

Lime sulphur protects plants from:
apple and pear scab, powdery mildew, rust mites, brown rot, grape erineum mite, leaf spot, cane spot, cane blight and rust blight scale, aphid, spider mites, ants.
As a side note, it is a better preventative control method then an emergency control method.

Lime Sulphur should not be used on sulphur shy plants (blackcurrant, grape, lemon, currants, apricots, raspberry, tomato, cranberry, melon)

Users of sulphur and sulphur-based fungicides should remember that sulphur is lethal to some beneficial insects, such as spiders and mites. Just as there are beneficial fungi, beneficial insects often prey upon insect pests that affect your yard and garden. Indiscriminate use of sulphur can result in the killing of these beneficials.

Also - lime sulphur causes phytotoxisity in plants. This can range from yellowing to leaf drop. It is caused when Lime sulphur is applied to leaves, and when lime sulphur is mixed with other chemicals and oils then those specified.

2) What is lime sulphur?
Lime sulphur is a mixture of calcium polysulfides formed by reacting calcium hydroxide, slaked lime, with sulfur. It is most commonly sold as a premixed liquid concentrate of 30% calcium polysulfide.

Sulphur is an effective fungicide/insecticide. The pests absorb the sulphur, resulting in the sulphur being converted to hydrogen sulfide - which then disrupts electron transfer. Sulphur also forms a protective layer around spores that inhibits spore germination.
Hydrated lime is corrosive. This is because it is highly alkaline (11.5). It dissolves the binding agents of protein bundles, allowing it to penetrate insect - and human - tissues readily. This includes hard to get insects like scale insects. The Lime corrodes through their shell, and the sulphur attacks.

3) A little history
Lime is one of the oldest chemicals humankind has produced. Sulphur comes raw. Monsieur Grison, head gardener at Versailles in 1851 is credited with boiling these ingredients together with water to create lime sulphur for pest control. Until 1904, gardeners and commercial gardeners were expected to make their own lime sulphur, there was no commercial product. The boiling of hydrated lime and sulphur creates fumes which are highly corrosive, making this a terrible task for anyone.

Lime sulphur and copper sulphur were the choices of grape farmers to control grapevine powdery mildew, in France. It moved to the Americas in 1885 to control San Jose scale. By the 1920’s, the product was very common. By the 1940’s, synthetic pesticide use was on the rise and replaced many of the uses of lime sulphur.
So far as I can tell, synthetic pesticides are better only in that they can be used on plants with foliage much more safely. They are not necessarily more effective; nor better for the environment.

4) Lime sulpher and bonsai
Ahh, yes. The last thing to note about lime sulphur. It is used by bonsai artists for jin and sharis - exposed heartwood. The artist paints the (very stinky) lime sulphur onto the exposed wood with a small paintbrush. For this, the product is quite perfect. The sulphur protects the wood from rot and insect damage, due to its toxic nature. The lime is revealed when the product dries. Lime, chalk, is white. This gives the wood an appearance very similar to that of aged, sun-bleached wood. Some artists mix a little soot or black paint with the lime sulphur to moderate the whiteness.

5) Saftey
Don’t let the warnings about lime sulphur deter you from using it. Lime sulphur is very effective. However, I advise you to heed the warnings on the label. That is - wear appropriate protection!

Saftey Appendix:
Calcium polysulphide 22%
Flammability (Specify Conditions): n/a
Reactivity & Under What Condition: Thermal decomposition.
Effects of Overexposure: Product is generally considered to
be of low to moderate toxicity, but may cause severe
irritation to eyes, nasal passages, throat and skin.
Corrosive to eyes and skin; may cause damage to eyes.
Sensitization of Material: Pre-existing skin or respiratory
disorders may be aggravated by excessive exposure to this
material.
Carcinogenicity: n/e.
Respiratory Protection: OSHA/NIOSH approved respirator with
organic particulate cartridge.
Eyes: Goggles/Face Shield
Gloves: Rubber or Impervious
Footwear: Rubber or Impervious
Clothing: Coveralls or Impervious apron when handling
concentrate.
Other: Work in well ventilated area.
Engineering Control: Local exhaust recommended.
Leak & Spill Procedures: Use appropriate protective
clothing during clean up. Absorb with an inert material
such as sand, soil clay or vermiculite. Sweep up and
dispose
FIRST AID MEASURES
If On Skin: Remove all contaminated clothing. Wash skin and
hair thoroughly with soap and water. Wash clothing before
reuse. If irritation persists, get medical attention.
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sources

http://www.greenearth.ca/products/product_e.php?prodID=459

http://www.extension.umn.edu/yardandgarden/YGLNews/YGLN-Jan0104.html

---------------- MATERIAL SAFETY DATA SHEET ---------------
LIME SULPHUR (PCP# 16465)
United Agri
C:\Documents and Settings\Owner\Desktop\Mark's\Lime Sulphur toxicology sheet.htm
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