There are a few vegetables that can be harmful if consumed. It's important to note that even some "safe" vegetables can cause digestive issues if consumed in large amounts or if they're not properly prepared. Here are some vegetables to avoid planting in your dog-friendly garden: Onions & Garlic: Both onions and garlic, along with chives and leeks, belong to the Allium family, and are poisonous to dogs. Ingesting these can lead to red blood cell damage and anemia. Mushrooms: While not all mushrooms are toxic to dogs, it's safer to avoid them altogether as certain types can be extremely toxic. Rhubarb: The leaves of the rhubarb plant are toxic to dogs and can cause drooling, vomiting, diarrhea, tremors, and changes in thirst and urination. Tomato Plants: While ripe tomatoes themselves are generally okay in moderation, the green parts of the tomato plant – stems, vines, leaves, and unripe tomatoes – contain solanine, which can be toxic to dogs. Raw Potatoes: Like tomatoes, raw potatoes, particularly green ones, contain solanine. Cooked potatoes are safe for dogs but keep them away from raw ones and potato plants. Wild Asparagus: The fern part of the asparagus plant can cause discomfort in a dog's stomach. Store-bought asparagus is generally safe, but wild asparagus should be avoided.