Summer is here – and that means it’s time to find and stop tomato hornworms from attacking and devouring your tomato and pepper plants in your garden!
As summer hits full stride, hornworms becomes incredibly active. And one thing is for sure – they can cause extensive damage in quick fashion to the nightshade family of plants. The tender leaves of tomato, pepper, potato (and eggplant and tomatillos too) are the perfect diet for newly hatched worms.
It seems like the pest arrives earlier and earlier with each passing year. For us here on the farm, we spotted our first hornworm in mid-June. But now that July is here, they are showing up on our plants in greater numbers – and as always, the key to success is finding them as fast as you can to eliminate any risk of damage.
How Hornworms Arrive – How To Find & Stop Tomato Hornworms
There are actually two types of hornworms – tomato and tobacco. Although they look nearly identical, you can tell the difference between them by the tiny horn upon their head. Tobacco hornworms have a red horn, while a tomato hornworm is a green or slightly black horn.
Hornworms hatch from eggs that are laid early in the season by a moth. The moth is actually big enough that it is often mistaken as a hummingbird. The moth is actually the adult form of the hornworm. The adults fly about, feeding on nectar and laying eggs on host plants that can feed the young as they hatch. Unfortunately, the best host plants are tomato and pepper plants!
The eggs are tiny, green, and nearly impossible to locate and destroy. But when they hatch, the problems begin. As the hornworm gets bigger, so does its appetite. They go from eating a few leaves the first few days, to taking out entire stems and branches as they grow in size.
Growing Up Fast – How To Find & Stop Tomato Hornworms
One thing is for sure, hornworms grow fast! A hornworm can go from a tiny, just-hatched half-inch worm, to a four inch long massive creature in just 48 hours. And if left to grow uninterrupted, they can ruin a plant in less than a week.
Making matters worse, as they mature, they don’t just feed on foliage, but also begin to drill into the fruit as well. In fact, as you can see in the photo below sent to us by my sister, they will even eat hot peppers. She was certainly shocked to find a hornworm just hanging out by a half-eaten jalapeno pepper!
One thing is for sure, it can cause a lot of frustration for gardeners. Especially when they can see the damage – but often can’t seem to locate the culprit. The good news? As it turns out, there are a few simple ways to find these elusive creatures and remove them before the damage is done.
How To Find & Stop Tomato Hornworms
Unfortunately, there really is no other method for controlling hornworms besides finding them. In fact, it simply comes down to finding and destroying them before they destroy your plants.
One of the secrets works amazingly well in the daylight hours – while the other can help you find and locate them in the dark. Together, they can help keep your plants free and clear of the foraging pest.
Finding Hornworms During The Day
More than anything else, diligence is the key to keeping hornworm damage to a minimum. That starts with inspecting your tomato plants each and every day. In fact, in the height of summer, we check our plants twice, once in the morning, and again in the evening.
And just what are we looking for? First and foremost, we are looking for the tell-tale signs of the damage they leave behind. That is most often a complete stem or branch eaten down to a small nub. If you see this, it means you most likely have a larger version lurking somewhere on your plant – and you need to locate it before the damage gets worse.
Luckily, there is an easy way to find hornworms before they get big – and all it takes is training your eyes to look for the manure or droppings they leave behind. One thing is for sure, locating the manure of hornworms is far easier than just searching for hornworms on your plants.
Although hornworms are amazingly adept at blending in, their manure is not. They drop a very distinctive type of manure on leaves as they feed. And fortunately, by eating so much so quickly, they leave a lot of it behind.
Finding Small Hornworms – How To Find & Stop Tomato Hornworms
A young hornworm will leave behind tiny black specs of manure on leaves. They look almost identical to black coffee grounds. The good news is that once you train your eyes to look for the black specs – you will start to be able to spot them quickly. And where there is manure – the young hornworm is certain to be nearby!
The small manure droppings are exactly what you should be looking for as you walk your plants. It will take a bit of practice, but you will get extremely adept at finding the worms within four to six inches of the fresh droppings.
This is by far the best way to locate them early. If you were to simply look for them without the aid of a specific area – it would be next to impossible to locate their tiny green bodies. And finding the hornworms when they are young is a huge key to keeping your plants safe.
One to two day old hornworms feed on small leaves and stems, and their damage will be minimal. But let them get bigger, and the destruction mounts quickly!
Finding Larger Hornworms – How To Find & Stop Tomato Hornworms
If the hornworm has grown larger, the droppings will be even larger. Adult hornworm manure will be in the shape of a small sphere or pellet, and be anywhere from 1/8th to 1/4th inch in diameter. When you find adult manure, there are usually stems and leaves that have been devoured nearby as well.
If the manure is green, it is extremely fresh. That means the larger hornworm is probably staring right at you blending in on a branch. If it is darker in color and more dry, the hornworm is still nearby, but expand your eye search to about 1 foot around the manure sighting.
As you look for the pests, keep your eyes peeled more to the upper ends of branches and stems. Hornworms like to navigate to these areas instead of deep into the foliage.
Once you find the droppings and the hornworm, always brush off the manure that is present on the leaves. This way, on your next trip through, you will know any droppings you spot will be a sign a new hornworm is around.
Finding Tomato Hornworms At Night – The Black Light Flashlight Trick
One of the more interesting and quickest and easiest method to find and stop tomato hornworms is at night. And to just that, all you need is an inexpensive black light flashlight. Product Affiliate Link: Product Link : UV Blacklight Flashlight
Hornworms have a translucent body that will light up with a black light. The UV rays create a glow on the worms against the plants, making them easy to spot. Simply walk your rows, and shine the light on your foliage.
It is actually amazing how well this works. In fact, it is by far our favorite way to find them, especially when you can do so under the stars on a cool evening!
Here is to finding and stopping hornworms in your garden – and to keeping your plants safe! Happy Gardening, Jim and Mary.
Old World Garden
Jim and Mary Competti have been writing gardening, DIY and recipe articles and books for over 15 years from their 46 acre Ohio farm. The two are frequent speakers on all things gardening and love to travel in their spare time.
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