When used incorrectly, pesticides can pollute water. They also kill beneficial as well as harmful insects. Natural alternatives prevent both of these events from occurring and save you money. Consider using natural alternatives for chemical pesticides: Non-detergent insecticidal soaps, garlic, hot pepper sprays, 1 teaspoon of liquid soap in a gallon of water, used dishwater, or forceful stream of water to dislodge insects.
If deer are hungry enough, they will eat almost any plant. However, some plants are less appealing than others, depending on what your local population has learned to eat so far. Daffodils are often cited as being deerproof, along with glory-of-the-snow (Chionodoxa) and crocus. Unfortunately, tulips and lilies are deer favorites. You might ask some of your neighbors if they have had luck with any particular plants, then try those in small quantities as an experiment. Many gardeners use repellent sprays with varying success, but to be as effective as possible they must be applied and reapplied according to the instructions. Home remedies include using soap, blood meal, human hair, and so on, but in the end the only truly reliable solution is a deer-proof fence.