How to Make Garlic Garden Spray
To make a basic garlic spray to control pests and fungi in your garden, start by peeling a head of garlic. Next, pour the cloves into a blender or food processor along with 1 cup of water. Secure the lid and puree the mixture until the garlic is finely chopped, which should take about a minute. Add 3 more cups of water and 2 tablespoons of liquid soap to the mixture, then puree it for 1 more minute in the blender. Once it's blended, pour the mixture into a clean mason jar and leave it on the counter to steep for 12-24 hours. After that, strain the mixture through a fine-mesh strainer with cheesecloth and transfer the resulting liquid into a spray bottle.
Peel the garlic. Use your fingers to peel off the outer layer of skin from the head of garlic. Break up the individual cloves and transfer them to a large metal mixing bowl. Cover the bowl with another metal bowl of the same size. Hold the two bowls together and shake them vigorously for 10 seconds. Remove the top bowl and pick out the peeled garlic cloves. You can also use a large mason jar with a lid if you don't have two metal mixing bowls of the same size. Process the garlic in a blender. Transfer the peeled garlic cloves to a blender. Add 1 cup (235 ml) of the water and secure the lid on the blender. Puree the mixture until the garlic is finely chopped, about a minute. If you don't have a blender, you can use a food processor or immersion blender. Otherwise, chop or mince the garlic with a knife or garlic press and stir it together with the water. Add the remaining water and soap to the blender. Puree the mixture for an additional minute or so, until the garlic has been liquified. The soap will help the mixture stick to the foliage in the garden, but it also acts as a pesticide in its own right. You can use any liquid soap you like, such as dish or castile soap. Steep the mixture overnight. Transfer the pureed mixture to a clean mason jar and screw on the lid. Leave the mixture on the counter for at least 12 hours, and up to 24. The longer the mixture steeps, the more time the garlic will have to infuse the water with pungent sulfur compounds. Strain the mixture. Line a fine-mesh strainer with cheesecloth and position the strainer over a bowl. Pour the mixture into the strainer to remove the chunks of garlic. Give the cheesecloth a gentle squeeze to remove as much of the liquid as possible. Straining the mixture will prevent the garlic from clogging the nozzle on your spray bottle. Transfer the mixture to a spray bottle. Insert a funnel into the mouth of a clean spray bottle. Pour the garlic liquid into the spray bottle. Remove the funnel and screw on the lid. Use as necessary to control pests and fungi in the garden. Store the mixture in the refrigerator and use within a week. Chop the garlic and onion. Use a knife or garlic press to mince the garlic. Move the onion to a cutting board and use a sharp knife to dice it finely into small cubes. Transfer the minced onion and garlic to a large saucepan. Add the water and cayenne to the saucepan. You can use red pepper flakes in place of the cayenne, or a fresh hot pepper if you like, such as a jalapeño or habanero. When using a fresh pepper, mince it finely before adding it to the pot. For additional pesticide properties, add three to four fresh or dried mint leaves to the saucepan as well. Mint works as a repellent for ladybugs and other beetles. Boil the mixture. Put the lid on the saucepan. Bring the water to a boil over medium-high heat. When the water is boiling, lower the heat to medium and continue simmering for an additional 15 minutes. Then, remove the pan from the heat and set it aside. Leave the mixture to steep. With the lid on, allow the garlic, onion, and cayenne mixture to cool for at least 12 hours, and up to 24. This will give the sulfur and oils from the vegetables time to infuse into the water. Strain the mixture. Pour the cooled mixture into a cheesecloth-lined strainer that's positioned over a bowl. This will remove the solid pieces of garlic, onion, and pepper, and leave nothing but a sprayable liquid behind. Transfer the mixture to a spray bottle. Use a funnel to prevent spills when you pour the mixture from the bowl into the clean spray bottle. Use as necessary in the garden to eliminate pests and animals that are feasting on your leaves. In the refrigerator, this mixture will last for about a week. Spray plants to deter pests and powdery mildew. The garlic in these sprays has antibacterial, antifungal, and insect-repellent properties. When you spray foliage in the garden with a garlic spray, it will eliminate a number of common garden problems. Garlic can: Repel aphids, slugs, caterpillars, ladybugs, and other insects Deter deer, rabbits, and other animals that could eat your plants Kill powdery mildew Apply spray to the foliage in the evening. Hold the spray bottle 6 to 12 inches (15 to 30 cm) from the plant you want to treat. Spritz the liquid to cover the tops and bottoms of the leaves with an even coating of spray. Many bugs like to hide on the underside of leaves, and powdery mildew can grow there too. It's best to apply the spray in evening, when the sun can't burn the leaves, and when insects tend to be more active. Reapply the spray every few days and after rain. For the best results, apply a coating of spray every 3 to 5 days (or possibly even daily) until the insects are under control, and once a week thereafter. Reapply after rainfall as well, because the precipitation will wash the spray from the foliage. Wash produce thoroughly before eating. The garlic spray is non-toxic, but you should wash fruits and vegetables well after harvesting to remove residue. Not only can the garlic spray be hot and spicy, but the dish soap will be unpleasant and bitter. 
Peel the garlic. Process the garlic in a blender. Add the remaining water and soap to the blender. Steep the mixture overnight. Strain the mixture. Transfer the mixture to a spray bottle. Chop the garlic and onion. Add the water and cayenne to the saucepan. Boil the mixture. Leave the mixture to steep. Strain the mixture. Transfer the mixture to a spray bottle. Spray plants to deter pests and powdery mildew. Apply spray to the foliage in the evening. Reapply the spray every few days and after rain. Wash produce thoroughly before eating. 