When the Havahart company asked me if I wanted to trial* its Critter Ridder® repellent products I eagerly agreed. I was particularly interested in trying the shake on product, which claims to deter critters, such as squirrels, from digging. With high hopes and great expectations, I sprinkled it around an Astrantia that the squirrels dug up repeatedly last fall. The only way it survived the winter was that I put a metal basket over it. Basket removed, product sprinkled, I retreated from the garden to see what would happen.
The next morning, I eagerly checked on the Astrantia. The result was, to quote the boy, "Epic Fail!" The Astrantia was no longer in the ground. I could swear I heard snickering from the trees.
But the squirrels weren't laughing, nor were the deer after I sprayed the Phlox pilosa, Heucheras, and 'Cobra' lilies out front with the Critter Ridder® spray repellent.
In addition to the tulip bloom incident, the deer had been snacking on the Phlox and the Heuchera, along with Symphyotrichum laeve. I didn't spray the ex-aster with the Havahart spray because I had already sprayed it with something else when the free trial products arrived. The lilies hadn't been sampled by the deer because they weren't large enough at the time.
I've applied the spray repellent to the growing lilies, which now look like this:
perfect deer candy. I'd call that a success. I also sprayed the 'Purple Prince' lilies that the squirrels repeatedly dug up and munched on last fall. They have remained unscathed, so the result there is "squirrels thwarted!"
Deer aren't one of the nuisance animals that the Critter Ridder® spray is designed to repel, but it seems to work for this off-label use. It's probably best to alternate it with another spray-on repellent like Liquid Fence®. I like both those products because they don't spot or discolor foliage or buds the way other spray repellents can. This spray repels by taste and scent, which is very important, as you don't want the wildlife to have to sample your plants before discovering that they are unpalatable. It is safe for use around kids, pets and wildlife.
Bottom line, I can't recommend the shake on product for repelling squirrels, but I can recommend the spray-on Critter Ridder® when applied to new growth. I don't know if it lasts for 30 days because it hasn't been 30 days yet, but so far, so good.
*The Havahart company sent me one canister of the shake-on product, one bottle of the spray, and a really nice polo shirt with the company logo for free. As should be evident, receipt of these items did not affect my review.