Loading ...
My wife wanted to get into tomato growing after getting a couple of EarthBoxes (that we love, but find way overpriced… you can build something similar yourself from 1/10th the cost if you are interested) and noticed that after a few months of excellent tomato production, we started to see quite a bit of stalk and leaf damage on the plants, and tomato production fell off almost completely.
Besides the thicker parts of the stalk looking like they were splitting and drying up, we saw a lot of black spots on the plant. After some googling of what we thought it was (fungus) we came across a forum post that mentioned “hornworms”.
At first we were doubtful that the problem was hornworms, after all, we hadn’t seen any worms on the plants. We read a bit more about them and found out apparently that they:
- Can easily land on the plants as larvae even if the plants are in a pot elevated off the ground
- Are notoriously hard to spot on the plants because they are camaflauged excellently
- Can totally destroy your tomato plants with the side effects we were seeing (stalk and leaf damage)
We eventually figured out that the black spots weren’t fungus, but were the worm’s poop. After about 20mins of looking for the worms and finding nothing, we decided to test out a new strategy for finding hornworms:
- Hose the plant down completely every mornng
- The following morning, look for black spots, likely indiciating the vicinity of a new hornworm
- Smash the worm
So we hosed the plant off really well, washing away all the existing poop and waited until the next morning. Low and behold we found our first worm, sure enough they are really hard to find and blend almost perfectly with the plants.
On that first day we actually found a total of 3 worms and smashed them.
Over the course of the next month or so we have found about 3 worms a week. Unfortunately we hadn’t been looking for worms for the last 4 days and headed out to do a worm search this morning and came across one of the biggest horn worms we had ever had, not quite the size of the one in the picture, but up there.
Upon further investigation we found another worm almost the same size and 3 more smaller worms (but all bigger than the “small” worms we were finding at the beginning of the worm-hunting a few weeks prior… it seems that these things have been on the plant the entire time, all these weeks that we’ve been hunting, and just growing un-noticed).
If you plan on growing healthy tomatos, it seems utilizing the “hose the plant off and hunt” trick is going to need to become a daily occurance to keep these damn things off the plants. We didn’t find this out until our tomato plants took some serious damage, so we hope this helps some of you other folks out there.
Loading ...
September 8th, 2008 at 10:46 am
Maybe you could encourage wasps to colonize the worms. If you are lucky, then this could happen:
http://www.extension.umn.edu/distribution/horticulture/images/M1224-1.jpg
A more practical endeavor may be to try insecticidal soap, such as:
http://www.gardensafe.com/ProductCategories/indoorinsecticide/InsecticidalSoap/
This is safe to use on edible plants (it is the only treatment I apply to my garden). The downside is that it is short-lived, but it is a safe way to try to deal with many types of insects — I have good luck keeping aphids away from my tomatoes with this.
September 8th, 2008 at 3:01 pm
tdod,
Thanks for the pointer on the garden-safe soap, wasn’t even aware of that… I think that’s something we are definitely going to look into next season.
Also the wasp-larvae issue… we have a wasp nest about 20ft from the tomato plants, but so far… no larve… I have no idea what the wasps are waiting for. Then again if I saw wurms with those huge parasites on them, I think I’d just set the whole tomato plant on fire.
June 17th, 2009 at 5:32 pm
I have about 14 hanging buckets with tomato plants that were doing fantastic, till I found the ‘hornworm’. I have become a pro at it though….look on your leaves for little black droppings..horn poop…I ain’t kidding..if you find a ’sixpack’ of them…look above and Trust me…there is a big one up under the leaves from it. Also if you have Pepper plants..they love these too have found one in every pot I have growing, although easier to find then the tomato plant..they are still there under the leaves of the Pepper Plant. I have chickens so they love it when I find one, circle of life eh
Two plastic spoons and first thing in the morning and after dinner we go hornworm hunting, always look for the poop down below and you will find your hornworm, guarantied.
June 18th, 2009 at 5:50 am
Diane,
Excellent tips. Are you ever able to find them when they are small? We were only ever able to find them once they were the size of small trucks — that drove us nuts because by then they were ruining the poor plants
July 2nd, 2009 at 5:12 pm
Diane,
What is the best time to look for the worms? They are chomping my plants and I cannot see them in the afternoon. Are they easier to find in the morning?
Thanks.
Sharon
July 2nd, 2009 at 6:59 pm
Sharon,
We looked in the morning, but I don’t recall having better luck with 1 time of the day over the other — the trick is really what Diane outlined, to look for the black spots (their poop) and then look above that location for the worms… they are SURPRISINGLY hard to find, you can even be looking right at one and not notice it and then look around some more and back where you were already looking and finally notice it.
Also on an unrelated note, there were times when we could shake the plant lightly and listen very intently and hear little popping sounds the worms make as a defensive mechanism… they excreet foam when they are upset apparently, but that only helped us find them 1 time — looking for poop is more helpful.
Also a tip I would recommend is using a hose to wash the plants daily, to clean all the old poop off, so you can spot fresh poop right away each day.
It’s time consuming and frustrating… 1 other tip I would suggest you look into is picking up a pesticide spray and just killing the hell out of the worms — but if you are trying to be clean/organic and want to fight them to the death, those are the only tips I know of to share.
Good luck!