Pennyroyal Oil Is Not a Deterrent

The title about sums it up. I wondered if a strong-smelling essential oil would keep away my flax-chewer. My mother uses peppermint oil to discourage mice from chewing the insulation in the stove at our family’s cabin when we close it up for the winter. I didn’t have any peppermint on-hand Sunday morning, but I did have pennyroyal oil.

I saturated some strips of row cover:

pennyroyal oil on strips

Then I tied them to bamboo stakes:

strip tied to stake

Then I stuck them inside the beds so the cloth hung near ground level:

stake in position

On Monday morning, there was more damage, including three tall stalks felled immediately on top of stake-and-strip set up in the 5NN bed. Frustrating.

I realize there were many flaws with this plan. First, the volatile oils from an essential oil dissipate quickly, so by Monday morning I couldn’t detect any odor on the cloth anymore. Second, I only put in two of these stakes per 10 foot bed, so I hadn’t exactly created a “wall of smell”. Three, I still don’t know what’s doing this so I can’t really customize my defensive strategy.

Meanwhile, I have lost a lot of plants, mostly from the types 1602 and Lisa which are closest to a strip of grapevine, wild mint, roses, and Joe Pie Weed between the garden plot and the walking path. Cutting down some of these plants will provide less shelter, I’m assuming, but considering that the garden plot is in the middle of a conservation area, I can’t completely clear-cut the surrounding vegetation.