Thrips are microscopic insects capable of doing great damage to flowers and flower bulbs, as well as foliage. Thrips attack both indoor and outdoor plants and make short work of valuable houseplants. Frustrating as these pests are, not everyone is comfortable using pesticides, especially indoors. Fortunately, garlic and hot pepper emulsions are effective thrip killers. While there may be a faint garlicky-peppery scent in the air around the plants, this solution is definitely chemical-free.
Place all three bulbs of garlic and peppers in the blender. There's no need to peel the garlic, as you'll strain out the solids later on. Fill the blender 1/3 to 1/2 full with water, replace the lid and blend the garlic, peppers and water until liquefied.
Pour the liquid through a sieve or other straining tool to separate the solids from the liquids. Compost the solids and place the liquid in a 1-gallon container.
Fill the container with water and shake the liquid to mix it.
Pour 1/4-cup of the mixture into the second gallon-sized container. Add 2 tbsp of vegetable oil. The vegetable oil will help the mixture stick to the plant parts. Gently shake them together and fill the container with water.
Use that solution to fill a spray bottle. Test the solution on an inconspicuous part of the plant to ensure it doesn't burn the plant. Wait about an hour to see if it has any negative effect, and then spray the affected parts of the plant thoroughly.
Treat the plant daily until you notice a difference in health and growth.