How to eliminate poison oak toxins from garden compost
Can poison oak toxin be eradicated from compost?Will it be safe to grow vegetables also safe for humans to touch?
Sonoma County California
Thank you for your question. Unfortunately, the toxin in poison oak (urushiol oil) cannot be removed from the plants since it is in the sap of the plant. This source indicates that "Poison sumac, poison oak, and poison ivy all contain a highly irritating allergenic phenolic compound called urushiol (oleoresin). The most toxic being the resin 3-n-pentadecylcatechol. All parts of the plant, green or dried, contain these compounds. The oily resin is not volatile or soluble in water but is soluble in alcohol."
This source indicates that urushiol remains active for several years.
So, the danger is not to the plants; it is to the gardener. The only way to 'eradicate' it is to keep all parts of the plant out of the compost in the first place. I hope this is helpful. Good luck!