Many pests like to attack roses, such as aphids, beetles and flies. Luckily, there are methods for keeping insects off roses without using harsh chemical insect-control sprays. Some homemade insect repellents include chemicals like ammonia, but others use essential oils and other natural ingredients. Always test homemade sprays on one plant before treating your entire garden.
Organic gardeners have long used soap and water as a natural insecticide for roses and other plants. To make a soap spray, mix pure soap such as soap flakes or unscented dish soap with water until the soap dissolves, then spread suds on plants by spraying or with your hands. It is important to use pure soap without additives like whiteners or fragrance. because these chemicals can affect plants. Use 1 tbsp. of soap flakes or liquid dish soap per gallon of water.
Baking soda, or sodium bicarbonate, has long been used as a protection against black spots on roses. To make a baking soda insect spray, dissolve 1 tsp. of baking soda in 1 quart of hot water. Once it cools, pour it into a spray bottle and spray plants, making sure to cover both sides of the leaves. To make the spray stick to leaves better and add insect-killing power, add 1 tsp. of liquid dish soap.
Neem is an essential oil extracted from the African neem tree, which is similar to a chinaberry tree. The active chemical ingredient in neem oil, azadirachtin, kills insects when they ingest it and also inhibits many insects from laying eggs. You can buy neem oil from essential-oil retailers and use it as part of your own herbal insecticide blend, but neem oil insecticide sprays are also available at most gardening stores.
The household cleaner ammonia can also kill insects such as aphids and beetles. To make an ammonia insect-control spray, mix 7 parts water to 1 part ammonia and spray on plants. Always test on a few leaves first to see how your roses react. Because ammonia can damage some plants, don't use it in the summer or when plants are stressed.
Insect Repelling Spray Recipe
Here is one recipe for a natural insecticide spray for roses using common kitchen items. As with any new insect-control product, always test this spray on one plant to make sure it will not harm your roses. Grind up one bulb of garlic and one small onion into a pulp. Add garlic, onion and 1 tsp. of dried cayenne pepper to 1 quart of water. Allow to steep for at least one hour, strain, and add 1 tsp. of liquid dish soap to the strained liquid. Mix well and spray on plants. Store it in the refrigerator.