Q: I want to try castor oil on my fescue lawn to evict my little mole friends. Will this harm my grass or shrubs?
A: There should be no distress to plants but I don’t think castor oil will repel moles either. I’ve heard this over-the-fence advice for years but I can find no research that shows that castor oil repels anything except small children in the nineteenth century. Sure, lots of folks say it worked for them, but the habits of moles are so variable that there is no certainty that the moles moved away any more often than they normally would. My advice is this: forget trapping, poisons and repellents. Simply press down tunnels with your shoes and moles will naturally go other places.