It is normal for dogs to eat grass at one time or another, but it can be harmful for your dog to consume other garden plants and houseplants. If you find your dog regularly eating plants, you may need to modify your landscaping or home decor so the dog no longer has access to the plants. You may also need to engage in a behavioral modification program to correct your dog's plant-eating behavior.
Move houseplants out of your dog's reach inside your home. Place the plants on tables or plant stands that sit higher than your dog's head. If you have plants that produce hanging vines, either keep the vines trimmed back out of your dog's reach or keep the plants somewhere your dog can't get to them.
Teach your dog to stop eating your houseplants by shouting "No" when he approaches them. When your dog responds by moving away from the plant, praise him and offer him a treat or one of his favorite toys as a reward.
Spritz your houseplants with diluted lemon juice or place slices of lemon in the pots. Many dogs find the odor of citrus sharp and distasteful and they may avoid the smell when it is applied to your plants.
Keep your dog in his crate or in a closed-off room while you are away from home if you are having difficulty teaching him to avoid your houseplants. This will prevent him from getting into the plants while you aren't home.
Fence off your vegetable and flower beds to prevent your dog from having access to your outdoor plants. If you have a small dog, wire fencing may be sufficient, but if you have a large dog you may need a sturdier metal or wooden fence to keep your dog out.
Build raised beds for your flowers and vegetables to deter your dog from wandering among the plants. You can purchase raised bed kits at your local home and garden supply store or build your own using landscape timbers or concrete blocks.
Monitor your dog closely while he is outside to make sure he does not eat any plants. If your dog begins to show interest in a particular plant, shout "No" to deter him and reward him when he moves away. You can also spray your dog with the garden hose to deter him from eating your plants.
Sprinkle cayenne pepper powder around the border of your garden and flower beds to keep your dog out. Cayenne pepper contains capsicum, a substance which is very irritating to the eyes and nose, and its scent is usually enough to deter dogs.
Soak a stack of biodegradable coffee filters in vinegar or rubbing alcohol and lay them out to dry in the sun. Once the filters are dry, cut them up into small slivers then spread them around the perimeter of flower beds or plants you want your dog to avoid. The odors of both vinegar and rubbing alcohol are very pungent and many dogs avoid them.
Be consistent in correcting your dog's plant-eating behavior and always praise him when he responds to your correction. The key to modifying your dog's behavior is to teach him to associate the negative behavior with reproach and the desired behavior with praise. Once your dog makes these associations, he should choose to seek the praise of his master.