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Battling Hornworms – How To Find Hornworms Before They Destroy Plants!

July is here, and the daily routine to find and remove the hornworms attacking our tomato, pepper and potato plants is underway. And are they ever out in full force this year!

This has been an exceptionally active year for tomato hornworms in our garden. In fact, since our first hornworm showed up on July 8th, we have now removed nearly 50 from our plants.

Battling Tomato Hornworms
The hornworms have been appearing in record numbers in our garden. Our daily searches have already netted 45 of the plant-eating creatures in the just under 10 days.

Hornworms cause extensive damage in quick fashion to the nightshade family of plants. The tender leaves of tomato, pepper, potato and egg plants are the perfect diet for newly hatched worms.

But the real issue with hornworms starts as they begin to grow. As the hornworm gets bigger, so does its appetite. They go from eating a few leaves, to taking out entire stems, branches – and then drilling into the fruit.

damage from pests in the garden
Hornworms will strip leaves, stems and even small branches. But even more damaging, they will also drill into the fruit.

And do they ever grow fast! A hornworm will go from a tiny just-hatched, half-inch worm, to a 4-inch long bulging creature in just 48 hours. And if left to be, they will ruin a plant in less than a week.

Stopping Hornworm Damage

Unfortunately, there is really no other method for controlling hornworms besides finding them early in their life cycle – and destroying them before they destroy your plants. But, as you will see in the video below, can they ever be hard to find!

Hornworms are the king and queens of camouflage. Whether they are small or full grown adults, they can blend in as part of the plant with amazing skill.

blending in
Hornworms can be difficult to spot on tomato plants.

But the good news is, there is an incredibly easy secret to catching them in the act. And with a bit of practice, you will be amazed at how quickly you can find them and remove the destructive creatures before they can wreak havoc in your garden.

How To Find Tomato Hornworms Before They Damage Plants

More than anything else, diligence is the key to keeping hornworm damage to a minimum. For us, that means a morning and evening walk of our tomato, pepper and potato plants to look for any sign of their presence.

And although they are amazingly adept at blending in, locating the manure of hornworms is far easier than just searching for hornworms.

Hornworm Droppings

Hornworms leave 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!

And finding that manure is far easier than trying to spot tiny, or even full-grown hornworms on plants. But if you find the manure, it is amazing how quickly it will lead you to the hornworm!

Looking For Hornworm Droppings

A young hornworm will leave behind tiny black specs of manure on leaves. They look nearly identical to black coffee grounds.

This is exactly what you should be looking for as you walk your plants. If you spot them, a tiny hornworm is near. It will take a bit of practice, but you will get extremely adept at finding the worms within 4 to 6 inches of the fresh droppings.

hornworm manure from young hornworm
The droppings from a young hornworm look nearly identical to coffee grounds.

If the hornworm has grown larger, the droppings will be bigger as well. Adult manure will be pellet sized, anywhere from 1/8th to 1/4 inch in diameter. It is also usually accompanied by the tell-tale signs of stems and leaves devoured nearby.

If the manure is green, it is extremely fresh. And 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.

adult hornworms
Adult droppings are larger, and will be green if fresh, or dark if more than 6 hours old.

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 (thankfully!).

A Few Final Tips

Once you find the droppings and the hornworm – be sure to brush off all of 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. – and not spend your time looking for one you already found.

pruning tomato plants
Keeping plants pruned helps to make spotting hornworms easier.

Finally, remember keeping your tomato and pepper plants pruned will not only help grow healthier plants, but make finding hornworms an easier task as well! (See : How & Why To Prune Tomato Plants)

And if all else fails, you can always use a blacklight flashlight at night to find hornworms too. The UV rays create a glow on the worms against the plants, making them easy to spot!

Here is to finding the hornworms in your garden before they damage your plants! Happy Gardening – Jim and Mary.

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