You may remember me writing a few articles on enrichment for our dogs earlier this year, I wrote about and shared what I had learned about Sensory or Snuffle gardens with you. https://thewholedog.com/sensory-snuffle-garden/
While doing some research for future articles and my NR Puppy book this morning, I came across an online UK dog magazine that featured an article on sensory gardens for dogs. There are some nice photos of at least one sensory garden to help you better envision what you can do.
Enjoy! I know your dogs will.