We recommend the safest, pet-friendly plants:
Queen of the Meadow
The non-plant concerns in the garden include fertilizers, pesticides, slug bait, mulch, and garden tools. Talk to your local nursery about the safest options, read labels carefully, and store everything safely in sealed containers or out of reach. Try natural products like vinegar for weeds, coffee grounds, beer, and salt for slugs, and soap and water as a natural pesticide. Avoid cocoa mulch as it comes from chocolate manufacturing and can contain substances that will cause minor chocolate poisoning (vomiting, diarrhea, hyperactivity) as well as general irritation to the mouth, stomach and intestines.
Many mature dogs (and almost all cats) are discriminate. They might sniff, but they're not inclined to eat plants. Grass is often the exception and in small amounts, common grasses are safe. Ornamental grasses can be irritating to the mouth, throat, and nose so if you have a big grass eater, it is safest to avoid these plants.
Remember that puppies and kittens are an exception. They will eat anything. It still makes most sense however to always pick the safest plants possible for flower gardens and deck pots.