13 Ways to Get Rid of Caterpillars on Trees

On the verge of declaring an all-out world war on those caterpillars in your garden? There are so many ways to do that, but you just might end up nuking your own home.

It’s true that caterpillars can be irritating residents in your garden. We hate them for their grubby little bodies that get fat and squiggly as they eat away at our plants and trees.

Before resorting to harsh chemicals, consider natural remedies to avoid harming yourself or the environment. Here are some of the best and natural ways to get rid of caterpillars on plants!

1. Soap and Water

Difficulty	Easy ●○○○○
Speed	Slow-acting
Things You Need	• Personal protective equipment • Soap • Water • Spray bottle

A soap and water spray solution is a simple yet effective way to control caterpillar infestations. It works by disrupting the waxy cuticle that covers the caterpillar’s body. 

This solution causes them to lose water and eventually die of dehydration. This method is also effective in suffocating the caterpillars by clogging their spiracles. 

Spiracles are the tiny openings through which they breathe, and you want them to not breathe. We might read a bit technical from time to time, but that’s just how we roll.

How to Make Soap and Water Spray Solution 1. Mix a few drops of mild liquid soap with water in a spray bottle. The perfect ratio should not make the solution too thick. We recommend one to two teaspoons of liquid soap to a liter or quart of water. 2. Shake or swirl the content until the water turns soapy. Usually, the soap should blend right in with the water after a few shakes. We prefer swirling it to reduce the number of bubbles. 3. Spray the soap solution on the caterpillars. Get in there and hit those crawling caterpillars. Most of the time, they can be found hiding under the leaves to get away from sharp-eyed birds looking for a snack.

Why We Love Soap and Water Spray

What’s great about this method is that its ingredients are simple but effective. Now you know that soap isn’t just for cleaning your hands but it also cleans your trees of pests.

We might sound like we’re kidding, but we’re not. The soap is a surfactant, allowing water to penetrate the caterpillar’s waxy cuticle, causing it to suffocate and “drown”.

If you want to get even with the caterpillars, make sure to thoroughly coat the areas where they’re present. Spray them down until they’re completely covered.

Remember to reapply the soap solution regularly. Rain or watering may wash away the soap residue and make the treatment ineffective, which can be frustrating.

This method may not be effective against all species of caterpillars. Just like people, some will have thicker coverings that may be more difficult to penetrate. 

In this case, you’ll need to keep your eyes zeroed in if this is working on your targets. If they don’t seem to be affected, you might want to try other methods.

Be warned: this soap solution may also harm beneficial insects that visit your garden. These include friendly bees and hungry ladybugs that pollinate or protect your plants.

We recommend using a mild soap that is safe for plants. Also, it’s best to rinse the plant thoroughly after treatment so that only the caterpillars are the focus.

2. Handpicking

Difficulty	Easy ●○○○○
Speed	Slow-acting
Things You Need	• Personal protective equipment • Soap • Water • Bucket or large container

This method is perfect if you have only a small caterpillar population in a specific area. It also works in targeting individual worms that may be causing damage to specific areas.

We hate having damaged leaves, stems, and flowers. It irritates us right to our souls and that’s why it’s we want to remove these crawling culprits as soon as possible.

To effectively pick caterpillars by hand, it’s important to first identify the caterpillar species. This will help you determine if that little sucker is harmful to the plant.

You can then find out if the caterpillars can cause irritation to your lovely skin or instigate other health problems. If they do cause harm, use protective gear such as gloves.

But always err on the safe side, even if you believe those caterpillars will not harm you. Never stay complacent when handling them.

Nature can be tricky, and even the cutest insect can easily harm people. Anyway, once you have your gloves on, you can begin to pick them off. 

How To Do Handpicking 1. Inspect the plant for signs of any caterpillar activity. You can tell from visible signs such as damaged leaves, flowers, or even fruits. And of course, if the caterpillars are physically there. 2. Carefully remove any caterpillars you find. Make sure to handle them gently so you won’t end up with squished pests. Cleaning up frequently can make the work even longer. 3. Avoid injuring them as it may cause them to release any harmful substances. You wouldn’t want to have any hairs or caterpillar excretions on you. These can be potentially irritating, especially if you have allergies or other sensitivities. 4. Refrain from injuring the plant as well. After all, the reason why you’re doing this is to keep it healthy. So keep your touch light but your determination strong! 5. Drop the caterpillars in the bucket of soapy water. This will drown them as they slowly suffocate. It may sound bad, but you have to remember that they’re also damaging your plant. 6. Continue until all caterpillars have been removed. They really love to hide under leaves. Some have become so devious that they’ve learned to look like leaves, bark, and even the head of a snake!

Why We Love Handpicking

This method is best suited for small infestations. Otherwise, it can be time-consuming for larger infestations and you may end up exhausted or sunburned.

Can you imagine getting your skin damaged and burned yet the enemies are still around? If you have a large caterpillar population, look for other options on this list.

3. Neem Oil

Difficulty	Moderate ●●●○○
Speed	Slow-acting to medium speed
Things You Need	• Personal protective equipment • Neem oil • Soap • Water • Bottle sprayer

Neem oil is a natural insecticide that is derived from the neem tree. It works by disrupting the feeding and reproductive cycles of insects and pests, including caterpillars.

When neem oil is applied to plants, it’s absorbed into the plant tissue. In turn, it affects the insect pests that feed on the plant because neem oil contains a compound called azadirachtin.

This compound inhibits the insect’s ability to feed and also disrupts its hormone levels. As a result, they find it difficult to mate and reproduce.

This method is best suited for small infestations. Otherwise, it can be time-consuming for larger infestations and you may end up exhausted or sunburned.

How To Do Neem Oil Solution 1. Identify the species of caterpillar and determine if neem oil is effective against that particular species. You definitely want to know what you’re up against. If you notice a particularly annoying species, you can tailor your solution to target your needs. 2. Read and follow the instructions on the label. Most neem oil products have the suggested recommended ratio. Try to follow this proportion so that the solution is as effective as it should be. 3. Avoid using higher concentrations other than recommended to prevent damaging the plants. Too much of a good thing can be bad. To avoid burning your plant’s leaves, keep to the recommended ratio and dosage of the neem oil product. 4. Spray all over the entire plant, including the undersides of the leaves and stems. The best time to do this is a few hours before sunrise or after sunset. Allow some time for the solution to dry off before getting exposed to the sun. 5. Reapply every few days, especially after watering activities or rain. Water can eventually remove the neem oil solution from the leaves. To keep those pesky pests off, reapply as frequently as recommended on the product!

Why We Love Neem Oil Spray

One of the benefits of using neem oil as an insecticide is that it’s safe for humans and pets. It’s also safe for beneficial insects such as bees and ladybugs. 

Yes, we know they’re insects but these are the insects that keep away pests that damage plants. Think of keeping beneficial insects as your garden pets, not pests.

You also need to note that neem oil can be harmful to some species of aquatic life. During application, care should be taken to avoid runoff into water sources.

One time, we were completely unaware that our neem oil solution had gotten into our koi pond. We ended up with one casualty and three survivors.

The lesson of that day: always consider the surrounding environment even if the treatment is natural and organic. It’s a bit safer to know the consequences beforehand.

4. Garlic and Chili Spray

Difficulty	Moderate ●●●○○
Speed	Slow-acting to medium speed
Things You Need	• Personal protective equipment • Garlic cloves • Fresh chili peppers • Water • Bottle sprayer

Garlic and chili spray is a natural and effective way to control caterpillars on plants. This spray works by repelling caterpillars with the strong odor and spicy taste of both garlic and chili. 

When the caterpillars encounter the spray, they are deterred from feeding on the plant. This causes them to move on to other food sources.

How To Make Garlic and Chili Spray 1. Wear gloves and avoid touching your eyes, nose, or mouth with the chili. Chili is particularly irritating if it gets into your sensitive body parts. If you want to prevent that crazy burning sensation, wear protection at all times. Blend fresh garlic cloves and fresh chili peppers with water. This may make you feel like you’re about to make amazing food, so enjoy the process. While you’re at it, why not use any excess for cooking? Strain and add more water to create a diluted spray. This will filter out all the large particles and ensure you have pure fiery liquid to fight caterpillars. This is your fuel and it’s time to light up those pests. Spray all over the entire plant, including the undersides of the leaves and stems. You know the eye-watering burning sensation we get from chili peppers? The caterpillars will feel that too so spray them and their food. Reapply every few days, especially after watering activities or rain. Unfortunately, this solution is not waterproof. So you’ll need to reapply. But then again, this is another chance to make amazing savory sauces and food!

Why We Love Garlic and Chili Spray

One of the benefits of using neem oil as an insecticide is that it’s safe for humans and pets. Plus, this trusty solution is also safe for beneficial insects.

There are two main benefits of using garlic and chili spray as a pest control method. One is that it’s non-toxic and safe for humans, pets, and beneficial insects.

Another is that it’s very effective at repelling small groups of caterpillars. Overall, garlic and chili spray should be used as part of an integrated pest management program.

Oh yeah, we forgot that there’s a third one. If you happen to make excess chili and garlic, you can just use them for stirfries, sauces, and toppings to make spice up food!

5. Bacillus Thuringiensis (Bt)

Difficulty	Moderate ●●●○○
Speed	Slow-acting to medium speed
Things You Need	• Personal protective equipment • Garlic cloves • Fresh chili peppers • Water • Bottle sprayer

Bacillus thuringiensis, also known as Bt, is a natural bacterial insecticide used by many gardeners. it’s often used to repel caterpillars and other insect pests. 

For this one, we’re going to get a bit scientific and technical. If this is a big bore for you, just skip to the how-to.

There’s something about knowing how things work that fascinates us. Getting to understand various chemical reactions just brings out our inner nerd.

Anyway, this bacterium produces a toxin that targets the larvae of certain bug and insect species. This includes many types of caterpillars, which brings a smile to our faces.

When caterpillars eat leaves laced with Bt, the toxin paralyzes their digestive system. This causes them to stop feeding and eventually die, causing us to smile even more.

The toxin works by binding to specific receptors in the caterpillar’s stomach. This disrupts the normal functioning of their gut cells and ultimately leads to their death. Yay!

Bt is available in various formulations, including liquid sprays, dust, and granules. It can be applied to plants using a variety of methods, so use one that works out best for you.

Consequently, they can be found as foliar sprays, soil drenches, and injections. When applied correctly, Bt is found to be highly effective at controlling caterpillar infestations. 

Plus, it has minimal to no impact on beneficial insects, like bees and ladybugs. And who doesn’t want to keep the good insects and kick out the annoying ones?

How To Use Bt 1. Identify the type of caterpillar in your garden. Bt is effective against many caterpillars, but it may not work on all species. Make sure to choose the product that targets the type of caterpillar you are dealing with. 2. Choose the right Bt product to target your specific caterpillars. The concentration of Bt will depend on the product you are using, as well as the intensity of the infestation. Bt is most effective when consumed and ingested by the caterpillars. 3. Mix the Bt according to the manufacturer’s instructions. You can’t just go willy-nilly and eyeball everything. Read the instructions so that it works as it should. 4. Apply the Bt spray to the affected plants, including the undersides and stems. These will be the leaves, stems, and sometimes flowers and fruits of the tree. The best time to do this is a few hours before sunrise or after sunset. 5. Reapply every few days, especially after watering activities or rain. The more frequently you apply Bt, the less it gets washed out. It’s better to use it on young caterpillars since older ones are usually unaffected by the toxin.

Why We Love Bt

One of the benefits of using Bt is that it’s highly specific to its targeted insect. This means that it has minimal impact on other organisms that are not the target. 

Additionally, Bt is a naturally occurring bacterium and breaks down quickly. This makes it an environmentally friendly pest management option.

This thrills us to no end because we love solutions that work quickly and effectively without harming anything or anyone in the process. Wouldn’t you agree?

But remember that Bt is only a preventative measure. It should be applied before caterpillar infestations become too large and cause significant damage to plants.

And to tell you the truth? We’ve been pretty successful at keeping those cretinous crawlies for some time now, so our plants are growing proof that Bt works.

6. Physical Plant Barriers

Difficulty	Moderate ●●●○○
Speed	Medium speed to instant
Things You Need	• Personal protective equipment • Tools • Netting, or • Mesh, or • Fences

Plant barriers are physical barriers that can be used to prevent caterpillars and other pests from accessing and damaging plants. Similar to keeping out annoying people.

There are various types of plant barriers that can be used. These include netting, mesh screens, and fences. Let’s take a quick look at each.

How To Use Netting 1. Secure the net tightly around the base of the plant. You want to keep it tight but not too tight that you strangle your plant or tree. Keep the pressure snug, just like you would a scarf on a cold winter day. 2. Alternatively, wrap the net around the plant to create a cage. Yes, you can go bigger. Why settle for a bit of protection when you can just cover the entire thing? Just make sure it looks pretty, though! How To Use Mesh 1. Attach to the sides of planters or raised beds. Think of it like building a protective shield. You want it to keep unwanted guests from getting in, much like you’d want the same thing for your home. 2. Ensure that they are tight, secure, and free from damage. Can you imagine how secure you’d feel if your doors and windows were broken and you don’t have an alarm? The same thing applies here. How To Use Mesh 1. Measure your area to determine how much fencing you’ll need. You don’t want to end up with too little fencing material. Trust us, we’ve been there and it’s not a pretty situation to be in. 2. Install your fences Fences should be tall enough to prevent caterpillars from climbing over them. Bury the bottom of the fence at least several inches in the ground. Caterpillars are hungry and wily and will do anything, such as crawling underneath fences, to feed. And sometimes, we humans are like that too.

Why We Love Physical Plant Barriers

Gardens are part of our self-care and mental health practices, and keeping toxic insects, animals, and people is part and parcel. Hence, the need to keep them distant.

Pant barriers should be regularly inspected and maintained. This will ensure that they remain effective at preventing caterpillars from accessing plants. 

Any tears or holes in the netting or mesh screens should be repaired immediately. Fences should be regularly checked for damage or wear and immediately repaired.

And remember, it’s okay to cut out toxicity in our lives. Toxicity doesn’t only come in one form, so it’s in your best interest to prevent and remove them from your life.

7. Diatomaceous Earth

Difficulty	Easy ●○○○○
Speed	Medium speed to instant
Things You Need	• Personal protective equipment • Diatomaceous earth

We’re going to get technical again, so hold on to your gardening gloves and hats! This time, we’re doing diatomaceous earth.

Diatomaceous earth is a natural powder made from the fossilized remains of tiny aquatic organisms called diatoms. It works by puncturing the caterpillar’s exoskeleton.

When diatomaceous earth is applied to plants, it forms a fine layer of powder on the plant parts. When caterpillars come into contact with the powder, it sticks to their bodies.

The powder then absorbs the waxy outer layer of their exoskeletons, causing them to dry out and die from dehydration. Doesn’t this sound great?

How To Use Diatomaceous Earth 1. Wear protective gloves and a dust mask to avoid irritating your respiratory system. You might think it looks harmless, but it can get rough inside your eyes, throat, and lungs. Unless you’re a zombie, diatomaceous earth can still harm you. 2. Sprinkle a thin layer around the base of or directly on the affected plants, including the undersides of the leaves and stems. Well, you can apply it a bit thicker if you’re feeling a little extra. As long as diatomaceous earth is there, it’s bound to keep caterpillars out. 3. Be sure to reapply after rain or watering as the powder can become ineffective when wet. This powder can get washed off, leaving your plant vulnerable to pests. Just sprinkle some more if you have wet or rainy days. How To Use Diatomaceous Earth 1. Wear protective gloves and a dust mask to avoid irritating your respiratory system. You might think it looks harmless, but it can get rough inside your eyes, throat, and lungs. Unless you’re a zombie, diatomaceous earth can still harm you. 2. Sprinkle a thin layer around the base of or directly on the affected plants, including the undersides of the leaves and stems. Well, you can apply it a bit thicker if you’re feeling a little extra. As long as diatomaceous earth is there, it’s bound to keep caterpillars out. 3. Be sure to reapply after rain or watering as the powder can become ineffective when wet. This powder can get washed off, leaving your plant vulnerable to pests. Just sprinkle some more if you have wet or rainy days.

Why We Love Diatomaceous Earth

There are basically two reasons: diatomaceous earth is affordable and easy to apply. It doesn’t take a rocket scientist to use it, trust us.

A word of warning, though: diatomaceous earth can harm also beneficial insects, so use it with caution. That warning also applies to beneficial humans, by the way.

8. Companion Planting

Difficulty	Easy to moderate ●●○○○
Speed	Medium speed to instant
Things You Need	• Personal protective equipment • Gardening tools • Selected companion plants

Companion planting involves growing certain species of plants next to each other. The point is to repel pests and promote healthy growth, similar to having good neighbors. 

Certain plants, such as onions, garlic, and chives, produce strong smells. Caterpillars find these scents unappealing and will easily go away in search of other plants.

Companion plants can be grown around plants to deter caterpillars from feeding on them. Think of these plants as soldiers guarding a castle.

Other plants, such as marigolds and nasturtiums, can attract beneficial insects that eat caterpillars. Examples of companion plants are:

• Tansy
• Sage
• Basil
• Rosemary
• Nasturtium
• Dill
• Marigold
• Daisies
• Sunflowers
• Garlic
• Onions
• Chives

We have a lot of dill plants growing around because they attract parasitoid wasps, which feed on caterpillars. Plus, dill makes our salads taste better.

How To Do Companion Planting 1. Identify the companion plant you want to cultivate. Of course, you’ll have to check if your selected companion plant works well with your plant and repels its pest. Otherwise, why plant it? 2. Plant them near or around your plant. Ever heard of the concept of using a moat? This one’s similar but in the context of using plants instead of water. 3. Cultivate your plant and its companions. Think of your companion plants as soldiers guarding the king. You have to give them water and food so they end up strong and able to resist invaders.

Why We Love Companion Planting

Companion plants bring color, scent, and taste to gardens and kitchens. Try growing at least one to see for yourself.

Companion planting works by taking advantage of the natural relationships between different plants. This is because some plants repel or attract certain insects. 

For example, some plants contain natural compounds that act as insect repellents. On the other hand, other plants attract beneficial insects that prey on pests.

These insects can help control caterpillar populations by eating them or laying eggs on plants that caterpillars feed on. These eggs then hatch into larvae that feed on pests.

Companion planting can also help promote plant health and resilience. This can make plants less susceptible to caterpillar damage. 

When it comes to repelling pests, our voices have become a bit hoarse over the years. This is probably why we’re writing this for now instead of making a video.

9. Vinegar Spray

Difficulty	Easy to moderate ●●○○○
Speed	Medium speed to instant
Things You Need	• Personal protective equipment • VinegarWater • Dish soap or vegetable oil • Bottle sprayer

Vinegar spray is a natural and effective way to control caterpillars on plants. Vinegar, particularly white vinegar, has strong acetic acid content.

This compound can kill or repel a variety of pests, including caterpillars.

How To Make Vinegar Spray 1. Mix one part vinegar with three parts water. Don’t stray from this ratio. Too much vinegar can kill plants and you wouldn’t want that unless you’re on a warpath to kill every plant in sight. 2. You may add a small amount of dish soap or vegetable oil to help the solution stick to the plants. Vinegar normally doesn’t stick to leaves. Adding one of the two can help it stick better to the parts of the plant. 3. Spray all over the plants, including the undersides and stems. Hit every nook and cranny because caterpillars tend to hide there. Coat the undersides of the leaves too, because caterpillars just love it there. 4. Reapply every few days, especially after watering or rain. This is one of those applications that are not waterproof. So to keep caterpillars away, you’ll need to reapply every so often.4.

Why We Love Vinegar Spray

Sharp and pungent, vinegar sprays usually make us sneeze. But their effectiveness is nothing to sneeze about, though.

When sprayed on caterpillars, the vinegar solution works by disrupting their body’s pH balance. This can cause them to experience dehydration and eventually death. 

The acetic acid in the vinegar also acts as a natural insecticide. This compound damages the caterpillars’ exoskeleton and causes them to dry out and die.

Note that vinegar spray can also harm your plants if used too heavily or too frequently. High concentrations can damage or burn parts of the plants, so use it moderately.

It’s best to test the solution on a small area of your plant. After patch-spraying, monitor it for a few days before spraying the entire plant to avoid any possible harm.

Vinegar spray can be used as a spot treatment on individual plants. You can even use it as a general spray on the surrounding soil and foliage, though always be careful.

You have to remember that it’s still a form of acid, which can eventually wear out organic matter such as plants. Oh, and avoid spraying vinegar on metal items!

10. Floating Row Covers

Difficulty	Moderate ●●●○○
Speed	Medium speed to instant
Things You Need	• Measuring tape • Pen • Paper • Floating row covers

Floating row covers are used to prevent adult moths from laying their eggs on susceptible plants. Some days, they can look ghostly, and on other days, magical.

These covers are made of lightweight fabric and are placed directly over the plants. Imagine a dreamy tent where plants get to grow in bright but indirect light.

The material allows sunlight and water to pass through while keeping insects out. These covers are particularly effective in keeping out cabbage loopers and other caterpillars.

How To Make Floating Row Covers 1. Measure the area to be covered using a measuring tape, pen, and paper. Also, measure at least twice. We can’t tell you how many times our initial projects went bust because we measured just once. 2. Get the appropriate length of floating row covers. Now that you’re sure you have the right measurement, go for it. Still unsure? Time to measure again. 3. Place the covers directly over the plants. This time you know you measured it right because the covers fit perfectly over the plants. See how important it’s to get the correct measurement? 4. Secure with stakes or pins to prevent pests from getting inside. You don’t want your covers to be flimsy and fly away every time a breeze comes through. Keep it secure so your plants are secure.

Why We Love Floating Row Covers

Row covers work to prevent caterpillars from accessing and feeding on the plants in a few different ways. Firstly, they physically block the caterpillars from reaching the plants. 

Secondly, the covers create an environment that is less favorable for pest development. These provide shade and reduce moisture, discouraging new caterpillar populations.

To be perfectly honest, we just love how cool they look. If we were plants, we’d probably love to grow under floating row covers too.

Row covers should be used before the caterpillars become a problem. Once caterpillars have already infested your plants, the covers will not be effective in removing them. 

We use row covers mostly for low-growing plants, but seedlings also benefit from the covers. The covers also protect the seedlings from birds and grazing animals.

Row covers can also be used in conjunction with other pest control methods. These include insecticides or sprays, providing a wider approach to pest control.

11. Cardboard Collars

Difficulty	Easy ●○○○○
Speed	Medium speed to instant
Things You Need	• Measuring tape • Pen • Carboard • Ruler • Pair of scissors • Tape

Cardboard collars are another physical barrier method used to protect plants from caterpillars. These collars are placed around the base of the plant.

We used to call these turtleneck wraps before we got corrected. But come on, they really do look like turtleneck collars on plants, don’t they?

These can prevent caterpillars from climbing up the stem and accessing the leaves. The collars are generally cut to fit around the stem of the plant a few inches above the soil.

How To Make Cardboard Collars For Plants 1. Measure the height and diameter of the plant. Again, nothing’s better than measuring more than once to get the right number. We also messed this up the first time we tried this. 2. Cut out the collar. This means using the measurements you made and cutting out a strip of cardboard that circles around your plant. It can’t get easier than that. 3. Dig a small trench around the plant. This will serve as support for your collar. Plus it makes you feel like you’re digging the foundation of a tall wall around your plant, which you are. 4. Place the collar around the plant. Your plant’s going to look quite fancy with the collar, so make sure it looks and feels good. Don’t make it too tight or too loose but just snug enough. 5. Secure the collar with tape. Or you could use a necktie or a scarf for that fashionable touch. Otherwise, the tape should be enough.

Why We Love Cardboard Collars

Well, aside from their insect prevention purposes, we like how the collars make each plant look uniform. Maybe it’s because we use collars that look pretty much the same.

Anyway, once in place, the cardboard collars create a physical barrier. This prevents caterpillars from climbing over or crawling under. 

As a result, caterpillars are not able to access the leaves of the plant and feed on them. Cardboard collars are effective when used preventatively.

This means they are only effective before the caterpillars become a problem. However, they do not provide a long-term solution.

This is because they tend to break down, especially when exposed to water. As a result, you may have to replace them periodically.

It’s important to note that cardboard collars may not be effective for all plant species. Some caterpillars are capable of burrowing through or finding other ways to get through.

Do you know what would be cute? Decorating your collars with drawings.

We had our kids draw all sorts of things on the cardboard collars using environmentally friendly pens. We even ended with one having a tie to represent his dad!

Anyway, we just had to get this thought out because you might find the idea creative too. Plus, it’s a great way to get kids, or kids at heart, involved!

12. Horticultural Oils

Difficulty	Moderate ●●●○○
Speed	Medium speed to instant
Things You Need	• Personal protective equipment • Horticultural oil • Bottle sprayer

Horticultural oils are also known as insecticidal oils or dormant oils. These are a type of oil-based pesticide used to control various pests, including caterpillars. 

Again, we’re going a bit technical here so you might want to skip it if it’s too much for you to handle. But for us garden nerds, we can’t get enough!

Horticultural oils work by smothering and suffocating the pests, leading to their death. Horticultural oils are derived from petroleum or plants, in case this matters to you.

These oils are formulated to be applied to the leaves and stems of plants. When the oil comes into contact with the caterpillar, it coats its body quickly and easily. 

This disrupts the insect’s ability to breathe by clogging its spiracles. Remember spiracles?

We discussed them before. Spinacles are the small openings in its exoskeleton through which the caterpillar breathes. 

The oil suffocates the spiracles, preventing the caterpillar from breathing properly. After some time, this causes the eventual death of the caterpillar.

How To Use Horticultural Oils 1. Choose a suitable horticultural oil for the plant and pest. Some oils work better with some plants and on their pests while other oils do less damage. Look for the oil that targets your specific caterpillar variety. 2. Mix the horticultural oil with water according to the manufacturer’s instructions. Just because it has “oil” in its name doesn’t mean it’s harmless. Use the correct ratio and dosage as instructed and you should be fine. 3. Apply the oil mixture to the affected plants using a sprayer and make sure to cover the leaves thoroughly. Caterpillars love to hide under leaves, so make sure to get in there. Get into the folds of the plants as well, especially in the cracks and crannies. 4. Reapply the horticultural oil as needed, following the recommended intervals. Some oils stick better than others too, so make sure to follow the manufacturer’s instructions on reapplication. It’s better to be safe than sorry!

Why We Love Horticultural Oils

Aside from being very effective, horticultural oils don’t cost that much. Plus, some have very long expiration dates.

Horticultural oils are usually effective against caterpillars in their early developmental stages. These are when they are most vulnerable to suffocation.

However, mature caterpillars may be less affected by horticultural oils. This is due to their thicker cuticles and larger body size. 

As a result, it’s more difficult to completely smother them. Horticultural oils are generally considered safe for plants and non-target organisms. 

This is because they are non-toxic and do not leave behind harmful residues. However, they can cause damage to plants.

This is especially true if applied in high concentrations or in hot weather. Under these conditions, they can lead to leaf burn or other damage.

Oh, yeah. If you get any of the oil on you while applying, immediately clean and rinse with water and soap so that your skin won’t get irritated.

13. Sticky Duct Tape Traps

Difficulty	Easy ●○○○○
Speed	Slow to medium speed
Things You Need	Duct tape

Slippery duct tape, also known as sticky tape, is a popular method used by gardeners against caterpillar infestations. It’s so simple that it’s probably the most popular.

This is mostly because it’s effective and affordable in trapping and removing caterpillars. Plus, duct tape works almost for everything, right?

How To Make Sticky Duct Tape Traps 1. Wrap a strip of duct tape around the affected branch or stem of the plant. Of course, this is assuming you have enough duct tape to cover the parts of the plant. Otherwise, you might want to get more duct tape from the store! 2. Ensure that the sticky side is facing outwards. The sticky part will be the one to trap the caterpillars as they try to make their way toward the leaves. Like an insect trap but just for caterpillars. 3. Check and replace the tape when necessary. If you have a lot of stuck caterpillars on the duct tape, replace the tape as often as needed. Continue until there are no more caterpillars found on the duct tape.

Why We Love Sticky Duct Tape Traps

Cheap, quick to install, and easy to use? What possible objections can people have about this handy home item?

It works by having the sticky surface of the tape capture any caterpillars that crawl over it. It effectively stops them in their tracks, immobilizing them in place and in confusion.

Being trapped in sticky duct tape prevents caterpillars from continuing to feed on the plant. As a result, trapped ones eventually die due to starvation or dehydration.

Plus, sticky duct tape is a non-toxic and chemical-free method of controlling caterpillars. This makes it a safe and eco-friendly option for gardeners if this is an issue dear to you. 

However, it may not be effective against all types of caterpillars. We recommend that you use this with other control methods for the best results.

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