It's not recommended to use dish detergent (like Dawn), laundry detergent, or hand soap (even the “natural” versions), since these soaps contain abrasive ingredients that could harm your plants. For DIY insecticide, organic pure castile liquid soap is the best solution since it's all natural and highly effective.
Kill Aphids and Bugs on Plants
Mix 1 to 1.5 teaspoon of dawn dish soap in a gallon of water and fill the mix in a spray bottle. Spray it on the affected plant parts, especially the underside of leaves and buds. The solution is safe for plants, but it will repel the pests.
Some gardeners purchase ready-to-use insecticidal soaps while others will make their own solutions using dish soap and water. If you are in the latter group, aim for a 2% soap solution: add just 2 teaspoons of dish soap to 1 pint of water.
You can often control aphids by wiping or spraying the leaves of the plant with a mild solution of water and a few drops of dish soap. Soapy water should be reapplied every 2-3 days for 2 weeks.
Vinegar spray
You can also add half a teaspoon of dishwashing soap to help the solution adhere. Shake thoroughly and apply to the affected areas. The acetic acid in the vinegar will treat a wide range of garden pests but it requires contact. If you have whitefly eggs be sure to spray under the leaves.
Control with natural or organic sprays like a soap-and-water mixture, neem oil, or essential oils. Employ natural predators like ladybugs, green lacewings, and birds. Grow the right plants that attract predatory insects, plants that repel aphids, and plants that "trap" aphids.
If your home does not have a water softener, your bathwater and rinse water from dishes and laundry are all of good quality for irrigation. Soapy wash water from dishes and laundry might better be saved to flush the toilet, but can be used for irrigation if you're careful about certain possible problems.
2.5 tablespoons of liquid dishwashing soap (preferably Dawn or Lemon Joy) and not automatic dishwasher soap Mix with 2.5 tablespoons of vegetable oil per gallon of warm water. Make only what is needed for one day's treatment. An insecticidal soap like this is generally not harmful to plants, animals or humans.
Can I make my own insecticidal soap? Certainly! By mixing 2.5 tablespoons of vegetable oil and 2.5 tablespoons of pure liquid soap with 1 gallon of distilled water, you'll have a whole gallon of insecticidal soap for safely spraying plants in flowerbeds or the vegetable garden.
Vegetable Oil
Similar to soap spray, a vegetable oil insecticide is a good way to get rid of annoying bugs. The soap and oil combo coats the insects' bodies and helps banish them from your beloved garden. Use 1 tablespoon of mild soap (like dish soap or castile soap) to 1 cup of vegetable oil. Mix well.
Since dish soap breaks things down, it could be potentially hazardous to plants. If a cleaning product was to seep into the water supply that plants need, it could possibly negatively affect plant growth and development (Hall, 2014).
Insecticidal soap kill harmful insects like mites, aphids, thrips, white flies and immature leafhoppers. The fatty acids in the soap dissolve the insects' exoskeleton, causing them to dehydrate. Many gardeners turn to this foamy remedy not only because it's effective, but also because it is more eco-friendly.
Irish Spring soap does not always eliminate pests completely but can be a helpful tool to reduce the rate of attack on plants. Irish Spring won't hurt your plants, either, so if you're growing edibles you won't have to worry about contaminating your produce with chemicals.
Bar soap is made of lye (sodium hydroxide) and animal fat/plant oils. When sprayed on plant material, homemade soap mixes can break down the waxy protective coat and burn the foliage.
Coffee grounds are usually touted as a cure-all when it comes to controlling garden pests like aphids, snails, and slugs, but truth is… there's no truth to their pest-repelling power. Same goes for banana peels, which will not deter garden lice from your plants.
If insecticides are needed, insecticidal soaps and oils are the best choices for most situations. Oils may include petroleum-based horticultural oils or plant-derived oils such as neem or canola oil. These products kill primarily by smothering the aphid, so thorough coverage of infested foliage is required.
Excessive use of nitrogen-rich fertilizer, which encourages too much tender, leafy plant growth. Transplanting shock which stresses plants vulnerable for a few days to a week. A temporary springtime population explosion of aphids prior to the emergence of their natural predator insects such as ladybugs.
“Vinegar is a good cleaner because it's acidic, but when you add dishwashing liquid/dish soap to it (which is a base or neutral) - you neutralise the vinegar. You take away the very thing that makes it work well. “The dishwashing liquid works that well on its own. Adding the vinegar is a pointless step.”
Mix two tablespoons of Dawn dish soap with a gallon of water to make bug spray with Dawn dish soap. Transfer the solution into a spray bottle & utilize it as a spray for repelling mosquitoes.
Q: Does Dawn dish soap kill mosquito larvae? A: Yes, Dawn dish soap can kill mosquito larvae in standing water by suffocating them.