15 Homemade Organic Gardening Sprays That Actually Work

Back when I started my first garden, a certain celebrity gardener and his books of gardening concoctions were all the rage. You could tell when it was fundraising time on our local PBS station because they’d have him live in the studio, telling us that all we had to do was use items such as baby shampoo, instant tea and whiskey, and we’d be able to grow our best garden ever.

Those claims seemed pretty far-fetched to me back then, and now that I know a little more, I know that several of those concoctions were either just plain bad ideas or that one item in his recipe was the one that was actually doing the work while the rest were either unnecessary or possibly harmful to plants, insects and other soil-dwelling organisms.

So please know that my b.s. radar is at high alert when I see anything about homemade gardening sprays. With that in mind, here are 15 homemade, organic solutions for garden problems. I use them, and they work. And not one of them requires you to pour whiskey on your plants.

Pest Control Sprays and Concoctions

1. Tomato leaf spray is effective for killing aphids and mites. It works because the alkaloids in the tomato leaves (and the leaves of all nightshades, actually) are fatal to many insects. Simply soak 2 cups (473 milliliters) of chopped tomato leaves in 2 cups of water overnight. Strain the liquid the next day and discard the leaves. Add 2 more cups of water to the mixture and spray it on your plants.

2. Garlic oil spray is a great, safe insect repellent. Simply put three to four cloves of minced garlic into 2 teaspoons (10 milliliters) of mineral oil. Let the mixture sit overnight, and then strain the garlic out of the oil. Add the oil to 1 pint (473 milliliters) of water, and add 1 teaspoon (5 milliliters) of biodegradable dish soap. Store in a bottle or jar, and dilute the mixture when you use it by adding 2 tablespoons (30 milliliters) of your garlic oil mixture to one pint of water.

This mixture works because the compounds in garlic (namely, diallyl disulfide and diallyl trisulfide) are irritating or deadly to many insects. The oil and soap help the mixture stick to plant leaves. What insects does garlic oil repel? Whiteflies, aphids and most beetles will avoid plants sprayed with garlic oil. A word of caution: Don’t apply this spray on a sunny day, because the oils can cause foliage to burn.

3. Hot pepper spray is a great solution if you have problems with mites. Simply mix 2 tablespoons of hot pepper sauce, a few drops of biodegradable dish soap and 1 quart (0.94 liters) of water and let it sit overnight. Use a spray bottle to apply the spray to infested plants.

Hot pepper spray works because the compound capsaicin, which causes the “heat” in hot peppers, is just as irritating to insects as it is to us (if you’ve ever sliced a hot pepper and gotten any of it in an open cut, you’ll understand). This mixture also helps repel whiteflies, but it may have to be reapplied if you start to see the mites or whiteflies returning.

4. Simple soap spray is useful in taking out a wide variety of garden pests, including aphids, scale, mites and thrips. Just add 1 tablespoon of dishwashing soap to 1 gallon of water and spray the mixture on the pests.

Why does this work? The soap dissolves the outer coating or shell of the insects, eventually killing them.

5. Beer for the slugs. Sink a tuna can or pie plate into the ground, and add a couple of inches of beer, to about an inch (2.5 centimeters) below the top of the container. Beer works because the slugs are attracted to the yeast. It’s really important to sink the container into the soil and keep the beer about an inch lower than the soil. This way, the slugs have to go down after the beer, and they drown. If the beer is near the soil, the slugs can just have a drink and then go and munch some hostas when they’re done with happy hour.

6. Citrus rinds as slug traps. If you don’t have beer in the house, but you do have oranges, grapefruits or lemons, give this a try. You don’t even need to create a spray — simply place the citrus peels on the ground and collect the slugs they attract.

7. Newspaper earwig traps work well for reducing the population of these sometimes-pesky insects. Just roll up a newspaper and secure it with an elastic band. Dunk it in water to get it wet and lay it in the garden between problem plants. Check the trap daily and dunk the newspaper rolls into a bucket of water to remove the bugs.

8. Ground cinnamon or cayenne pepper sprinkled around your plants works by repelling, but not injuring, ants.

9. Red pepper spray works well for making your plants less tasty to mammal and bird pests. If bunnies, deer, mice, squirrels and birds are regularly messing with your garden, make the following mixture and spray target plants weekly. Mix 4 tablespoons (59 milliliters) of Tabasco sauce, 1 quart (0.94 liters) of water, and 1 teaspoon (5 milliliters) of dish soap. The capsaicin in the pepper spray will irritate the animal pests, and they’ll look for less spicy fare elsewhere.

Fungal Disease Solutions

10. Milk for powdery mildew. Mix up a spray that is 40 percent milk and 60 percent water and simply spray it on both sides of the leaves of affected plants. The milk works just as well as toxic fungicides at preventing the growth of powdery mildew. This mixture will need to be reapplied regularly, but it works wonderfully.

11. Baking soda spray for powdery mildew is a tried-and-true method for preventing powdery mildew. It needs to be applied weekly, but if you have a problem with mildew in your garden, it will be well worth the time. Simply combine 1 tablespoon (14.7 milliliters) of baking soda, 1 tablespoon of vegetable oil, 1 tablespoon of dish soap and 1 gallon (3.78 liters) of water and spray it on the foliage of susceptible plants. Baking soda spray works because it disrupts fungal spores, preventing them from germinating. The oil and soap help the mixture stick to plant leaves.


12. Vinegar works very well for getting rid of weeds in your lawn and garden. The main issue with vinegar is that it can harm other plants. I recommend using a foam paintbrush to brush the vinegar directly onto the leaves of weeds you’re trying to kill. This prevents the vinegar from getting onto other plants and ensures that the entire leaf surface is
coated with the vinegar.

13. Boiling water for sidewalk weeds. Boil some water, and pour it over weeds in the cracks of your sidewalks or driveways. Most weeds can’t stand up to this treatment, and your problem is solved. Just be careful when pouring!

14. Vinegar and salt for sidewalk weeds. I personally prefer pouring boiling water on sidewalk weeds, or pulling them. But if you have some really stubborn weeds, you can try using 1 gallon (3.78 liters) of white vinegar mixed with 1 cup (236 milliliters) of salt. Also mix 1 tablespoon (14.7 milliliters) of dishwasher soap into the solution, as this solution won’t stick to the surface of the weeds otherwise. Please note that this concoction will kill just about any plant it comes in contact with, so keep it away from your other plants, as well as your lawn.

Best Homemade Garden Concoction of All

15. Compost. Seriously, whether you’re an apartment dweller with a fire escape farm or a rural farmer, you need to be making and using the stuff. It adds nutrients, improves soil structure, increases moisture retention and increases the number of beneficial microbes in your soil. And that’s all besides preventing organic matter from making its way to the landfill.

I hope these ideas for safe, homemade organic garden concoctions are helpful. By having just a handful of inexpensive items on hand, you can take care of most common gardening dilemmas in your own, green way.


By Colleen Vanderlinden for home.howstuffworks.com.

This educational blog is a series of informative articles from the Penn State Master Gardeners volunteers plus news concerning the group and their activities. For more information, click here.