Planting a garden can be difficult if you have dogs. Dogs can get sick from snacking on certain plants and many plants are toxic to dogs. However, there are some that you can plant that won't harm a dog if he munches on the plants.
Dogs will eat plenty of vegetables if they get in your garden, and while most vegetables are not poisonous to dogs, the plants themselves may be poisonous. Plants from the nightshade family, such as tomatoes and peppers, are poisonous but have edible fruit. Still, other plants are safe or only cause a mild gastric upset.
Squash, gourds, cucumbers, beets, carrots, muskmelons are all relatively safe for your dog to chomp into. Lettuce, broccoli, spinach, kale, celery, cabbage and cauliflower are all safe for a dog to dig up and eat. Most plants that we humans eat the whole plant or the leaves are usually safe for dogs. There are exceptions, such as onions, but a good rule of thumb is that if the vegetable is safe for human consumption, the vegetable is usually safe for dogs.
Onions and garlic in large quantities can cause hemolytic anemia in dogs. Grapes can cause renal failure. Tomato and pepper plants can cause central nervous system depression, diarrhea, gastrointestinal upset, weakness and slow heart rate. Rhubarb causes kidney failure, tremors and excessive salivation. Also be careful with the types of chemicals and fertilizer you use around your dog. The chemicals can poison your dog if he ingests them. When in doubt, use fertilizers and chemicals labeled safe for use around pets.
If you wish to plant vegetables or vegetable plants that are poisonous to dogs, keep the garden fenced so that your dog won't get into it. Otherwise, plant only vegetables that are safe for your dog to snack on. Plan on a fence that your dog can't jump, climb or dig under. You can add a top with fencing if your garden isn't too big.
If your dog is more than 40 pounds or particularly athletic or tall, you should have a minimum of a 6 foot tall fence surrounding the garden. To prevent your dog from digging under the fence, purchase railroad ties or 8-inch wide boards long enough to cover the perimeter under the fence. Dig a trench beneath the fencing and partially bury the boards so the dog will have a hard time digging beneath the fence.
If you are unsure of the safety of a particular type of plant, visit the ASPCA Poison Control Website (located in References) or contact your local poison control center or state agricultural office to find out the toxicity. You can also ask your veterinarian about the types of plants you're considering having in your garden.