DIY Organic Pest Spray Options

Chamomile plant covered in aphids.

As our beautiful plant babies reach for the sun and begin to flourish, they inevitably attract pests such as aphids, thrips, whiteflies, spider mites, leaf miners, and leaf hoppers. We know that healthy plants are more resistant to pests and that interplanting pest-repelling, beneficial attracting herbs and flowers throughout our garden area will help to keep our garden balanced. Additionally, row covers help keep pests at bay while trap crops can draw pests away from our main crop. Still, these efforts may not provide sufficient control. Last spring, for example, I went away for a few days and returned home to aphid-infested chamomile (above picture).

It's beneficial to have additional pest control methods at our disposal. By utilizing common household ingredients we can avoid harsh chemicals, save money, and effectively target unwanted pests while minimizing the impact of beneficial insects. Let's examine how liquid soap, garlic, and hot peppers can be combined to create effective, organic pest control sprays.

Hot peppers, organic soap, and garlic are great pest control options.

Organic Liquid Soap: Compared to regular dish soap, which may contain harsh or synthetic chemicals, organic liquid soap is milder and less likely to harm delicate plant tissues or beneficial insects such as ladybugs, lacewings, and bees. Diluted organic liquid soap, such as Dr. Bronners Castile Soap, will effectively suffocate and kill soft-bodied pests making it an excellent option for natural pest control in the garden. I keep lavender and peppermint pure Castile liquid soap on hand as they cost the same as unscented, smell great, and both lavender and peppermint oil also aid in repelling unwanted pests.

Hot Peppers: Hot peppers contain capsaicin, a natural insect repellent and deterrent compound. When making homemade pest spray using hot peppers, it's best to use moderately hot peppers such as jalapeños, serranos, or cayenne. Extremely hot peppers like habaneros or ghost peppers can be too intense and may damage plants if not diluted properly. It's crucial to test hot pepper spray on a small area of the plant before applying widely to ensure that it doesn't cause damage, then adjust according to your pest control needs and plant sensitivity. Hot pepper sprays are generally safe for beneficial insects when used properly. Avoid spraying directly on beneficial insects, apply in the early morning or late afternoon when they are not present, and don't spray on a windy day so that it doesn't carry to unwanted areas.

Garlic: The sulfur compounds in garlic have natural insecticidal properties and can be used to repel and deter a variety of garden pests. The first time I tested garlic spray for pest control was on my aphid-infested baby chamomile plants. One spray and the aphids visibly started crawling away with much hast! The strong odor of garlic acts as a repellent to many common garden pests, can disrupt pest-feeding behaviors, and may also interfere with the reproductive cycle of some insects, helping to reduce populations over time. As with all plant treatments, testing a small area before applying it to the entire plant is important to ensure compatibility. In rare cases, garlic sprays applied in high concentrations or, in hot weather, may cause phytotoxicity (plant damage) on sensitive plants. Dilute appropriately, avoid spraying on hot days, and do not spray directly on beneficial insects.

Hot peppers and garlic can used in DIY natural pest sprays.

Here are a few organic pest spray combinations to consider:

Insecticidal Soap Spray:

• 1 tablespoon organic liquid dish soap

• 1-quart water
  

Insecticidal Soap and Hot Pepper Spray

• 2-3 fresh hot peppers (jalapeños, serranos, or cayenne peppers)

• 1 tablespoon organic liquid dish soap

• 1-quart water
  

Insecticidal Soap with Garlic and Hot Pepper Spray:

• 2-3 fresh hot peppers (jalapeños, serranos, or cayenne peppers)

• 4-5 garlic cloves

• 1 tablespoon organic liquid dish soap

• 1-quart water

Instructions:

• When including hot peppers in your spray, consider wearing gloves when preparing to avoid oil transfer onto your hands (your skin and eyes will thank you). Remove seeds if you prefer a milder spray, chop up a bit, and add to blender.

• If utilizing garlic in your spray, peel fresh garlic cloves and add to blender with water and peppers. Note that garlic powder does not have the same potency as fresh.

• Blend your garlic-hot pepper combination until the peppers and garlic are finely chopped, adding water as you go. (Do not add soap to the blender, think about it.)

• Let the mixture steep overnight for optimal power and then strain out peppers and garlic using cheesecloth or a fine mesh strainer.

• Pour into a spray bottle and add organic soap (about 1 tablespoon to every quart), shake and your spray is ready.

• Label and refrigerate unused contents for future applications.
  

Use larger spray containers when treating large areas.

Application:

1. Remember to test spray a small area and wait 24 hours before treating all plant(s). If plants show signs of sensitivity then dilute spray and test again.

2. Apply in the cool early morning or evening when beneficial insects are not present.

3. Fully apply to the top and bottom of leaves where pests tend to hide, remember that to be effective, organic insecticidal spray must come in contact with your desired target.

4. Treat every few days until pests are under control and then weekly to keep them from re-establishing. Unlike many insecticides that remain active once dry, insecticidal soap treatments lose their power once dry. This means less harm to beneficial insects and the need for regular treatments to interrupt the reproductive cycling of unwanted pests.

5. Avoid damaging plant membranes by not overtreating and do not apply in the heat of the day.

Organic pest control helps prevent harm.

There are numerous blends of natural ingredients that you can use to create cost-effective, organic pest-control sprays. Whether you use organic soap, hot peppers, garlic, or try something else, be mindful of the overall goal of finding balance. Healthy plants can withstand minimal pests that may provide dinner for our important pollinators. If we destroy a singular part of a natural ecosystem, we will create an imbalance that leads to other problems. Interplanting healthy plants, strategic trap crops, and organic insecticidal soap sprays can help ensure bountiful harvests without negatively impacting our environment. As you experiment with what works best for your garden, may you enjoy an abundant harvest while avoiding harmful pesticides. Happy growing!