If the leaves of rhubarb are poisonous, why put them in a compost pile? The question is self evident - why put poisonous material into a compost pile that will be returned to a garden?
Rhubarb Leaves in Compost
Certified GKH Gardening Expert
Compost containing decomposed rhubarb leaves can be safely worked into the soil of vegetable gardens. The leaves do contain poisonous materials (oxalic acid and soluble oxalates), however, these rapidly decompose in the compost pile and do not negatively impact compost quality. Oxalic acid and soluble oxalates are also not readily absorbed by the roots of plants.