Homemade Pesticides

I constantly get asked about what to do about Pests.  Typically, in my own garden, I don't do anything as my soils are so dynamic and rich that my plants don't get large infestations of pests.  I also just plant enough so that everyone gets to eat (including the bugs and the birds) and there is always enough left for us.  I think the best thing you can do to prevent pest-infestations is to adopt companion planting techniques, as well as feed with regular compost tea applications.  BUT, if pests are a real issue in your garden~ here are some of the top homemade-effective pest-prevention sprays that I have come across. No fancy ingredients required, everything you need is likely stocked in your kitchen and garden.

Tip: The best method of pest control in the garden is to keep your plants healthy so they don’t attract bugs. Fertilize plants as needed (see How To Make Compost Tea) and stay on top of weeds by pulling them as they appear or using weed killers (see Homemade Weed Killer Recipes & Tips). Begin treating for insects as soon as you notice signs of an infestation, the sooner you start the easier it will be to get rid of the pests.
Note: For recipes that require liquid dish detergent, I like to substitute with a gentler liquid soap such as liquid castille or a perfume free, gentle liquid hand soap.  Always stick to organic-non-toxic soaps and detergents.
As with all pesticides, take care when applying to food bearing plants, handling and storage of the pesticide. No one needs reminding I’m sure, but make sure to wash all produce well before consuming.

Natural Pesticides: Recipes

Rhubarb Leaf Pesticide Spray
1 cup rhubarb leaves
6.5 cups water
1/4 cup liquid dish detergent or soap flakes

• Cover rhubarb leaves with water and bring to a boil. Boil for 20 minutes then remove from heat and cool. Strain then add 1/4 cup liquid dish detergent. Spray on plants. Good for aphids, june beetles, spider mites, thrips.
• Rhubarb leaves are poisonous, take care when preparing and handling. Do not use on food bearing plants.

Garlic Tea Spray

• Make your own garlic spray by boiling a pint of water, throw in roughly chopped garlic cloves and steep until the water cools. Remove garlic bits then spray on plants (from Quick Tips For Plants & Garden).

Garlic, Peppers & Onion Insecticide
2 hot peppers
1 large onion
1 whole bulb of garlic
1/4 cup water

• Toss in the food processor and add water, blend until a mash is made. Cover mash with 1 gallon hot (not boiling) water and let stand 24 hours. Strain. Spray on roses, azaleas, vegetables to kill bug infestations. Bury mash in ground where bugs are heaviest. Good for thrips, aphids, grasshoppers, chewing and sucking insects.

Tomato Leaves Spray

• Crush leaves from a tomato plant and soak in water for a couple days. Strain then spray. Good for grasshopper and white fly control.
• Tomato leaves are poisonous, take care when preparing and handling. Do not use on food bearing plants.

Basil Tea Spray
4 cups water
1 cup fresh basil (or 2 TBS dried)
1 tsp liquid dish detergent

• Bring water to a boil then add basil. Remove from heat, cover and steep until cool. Strain. Mix in the liquid detergent then spray on plants. Good for aphids.

Onion Insect Repellent For Plants

• See details here: Organic Insect Repellent For Plants.

Salt Spray
2 TBS salt
1.5 gallons warm water

• Mix salt and water to dissolve, allow to cool to room temperature. Use for spider mites, caterpillars, cabbage worms and chewing insects.

Slug Bait Trap

• Set out beer in shallow containers to attract slugs, they’ll drown in the beer.

Diatomaceous Earth

• An all natural solution for insects of all kinds (ants, snails, slugs, etc.). Sprinkle diatomaceous earth on top of soil around plants with pest infestations.

Horticultural Oil Spray
1 TBS vegetable oil
1 tsp liquid dish detergent
2 cups water

• Fill a spray bottle with the ingredients then shake to mix.

Hot Pepper Spray
1/2 cup hot peppers (or 2 teaspoons cayenne pepper)
1 quart water
1 tsp liquid dish detergent

• Bring water to a boil, remove from heat and add peppers. Cover and steep until cool. Strain then mix in soap. If using cayenne pepper, no need to bring water to a boil first. Spray on plants.

Citrus Spray
2 cups orange peels (or lemons)
4 cups water

• Bring water to a boil, remove from heat and add peels. Cover and steep until cool. Strain and spray. Use the lemon mixture to repel white flies.

Dish Detergent & Baking Soda
2 TBS liquid dish detergent
2 TBS baking soda
1 gallon water

• Mix all ingredients together then spray on plants.

Peppermint Tea
1 TBS peppermint essential oil (can also use an infusion made with mint leaves, increase amount to 1 cup infusion)
1 quart water

• Mix together and use as an insect spray (good for ants).

Japanese Beetle Bait Trap
2 cups water
1 mashed banana
1/2 cup sugar
1/2 cup wine
1/2 tsp yeast

• Mix ingredients together and put in an old margarine container, cover with lid and set container out in the hot sun for a day. The next day, remove lid and set in garden where the beetles have been spotted (use a shallow container).

Rose-Beetle prevention: 

• My favorite way of ridding my plants of Rose-Beetles is actually just put a solar light into the garden near the plants that they love the most (eggplant, beans, roses etc...) as Rose beetles hate the light and only feed in the dark of the night.

Potato Leaves Tea
1 cup potato plant leaves
2 cups water

• Chop leaves then cover with hot water. Seal container and leave 24 hours in a sunny window. Strain then spray.
• Potato leaves are poisonous, take care when preparing and handling. Do not use on food bearing plants.

Neem Spray
1 TBS Neem soap (shavings)
1 liter water

• Add soap to water then let sit for an hour. Shake bottle then spray.

Working With Homemade Pesticides: Tips

• Apply the pesticide on top of the leaves as well as underneath–don’t overdo it, excess spraying can cause damage to plants.
• Most recipes can be used effectively with just a weekly spray. Excessive spraying may affect the plant as well as kill the good insects you want to encourage in your garden (earthworms, bees, ladybugs, etc.). If you aren’t seeing results with a 7 day spray, you can bump it up to 5 days but watch the plant carefully to make sure it can handle it without being damaged.
• Avoid spraying during hot sunny weather, spray late in the day to reduce the risk of plants burning.
• If it looks like rain, delay spraying the plants until the weather is clear since any rain will wash away the new treatment. If it has recently rained, wait till the plants are dry before applying treatment to prevent the recipe being diluted with water.
• When trying a new pesticide recipe on a plant, test it on just a few leaves first, and keep notes.  Sometimes pests come into our lives just to teach us something and to help expand our awareness and to better develop our ability to observe the natural world.