Have you ever noticed the little hairs on tomato plants?
Some varieties look downright fuzzy and others have just a few sparse hairs. There has been much study about why a tomato plant has hair, and we now understand that these fuzzy strands that look like hair have a very important role for the tomato plant.
Tomato plant hairs are actually called trichomes.
Your tomato plants are covered in trichomes. Some are long making your tomatoes look fuzzy. In the photo below, you can see the glossy strands of the long trichomes poking out all around the stem. But there are also super tiny ones that look more like little bubbles covering the surface of the tomato plant. Those bubbles are actually perched right on top of super tiny trichomes.
These tiny trichomes secrete essential oils which give tomato plants their wonderful scent.
It is precisely that scent that aims to repel some pests. The tomato plant can react to times of stress by altering the compounds within its trichomes to attempt to deter critters that may want to chomp on it.
It is presumed that the pests find the taste, scent, or texture of the essential oils unappealing. If you’ve grown tomatoes before, you know this is not a fail-proof method by any means. But who knows how many more pests would be present without the distasteful oils.
The leaves and fruit of tomato plants are also covered in trichomes.
As the stem, leaves, and fruit are covered with the essential oils, they form a barrier to bacterial, fungal, and viral infection in addition to trapping water and reducing evaporation.
That’s pretty cool, huh?
Why do trichomes matter to gardeners?
Trichomes are to blame for tomato fingers.
If you’ve worked with your tomatoes, you know what I’m talking about! A dirty black film builds up on our hands when you’ve been handling tomato plants.
It happens when you plant, prune, tie up, or harvest. The more time you spend with your tomatoes, the more it gets caked on your fingertips. Some people call it tomato tar.
I call it Tomato Fingers!
These fingers are somewhere in between the green and black stage. Probably with some red clay mixed in. But you get the idea.
It is the build up of the compounds on the trichomes that make that nasty film.
Remember that the trichomes secrete essential oils? Those oils are what become stuck to your finger and nails. They’re very sticky, and they don’t wipe off easily.
If you are familiar with this stuff, you also know that hand soap seems to just slide around on top of it. That is because the compounds are not water soluble. And don’t try to wipe it off with your hand towels because it will stain them!
The trick is to use a liberal amount of hand sanitizer and really rub it in. When it dries out do it again.
Then wash your hands with soap and water. The alcohol in the hand sanitizer dissolves the oils and makes it easier to wash your hands clean with soap and water.
Isn’t that cool that tomatoes can defend themselves with hair?! I am in awe of all the beautiful ways mother nature solves problems. The tomatoes needed a way to defend themselves. They don’t have arms or legs or brains, but they have hair. And they made that work. That’s neat.
If you like finding out cool things like this, please grow a garden. There’s lots of cool stuff to be found out there!
Need some help getting started? Check out these posts
Visit these additional sites for some seriously awesome tomato hair pics and more info about trichomes.
This amazing picture is from Phil Gates Blog where he has lots of amazing photos of plants.
I love extreme close-ups (obvi)! But I can’t top this one from Dr. Marcia Harrison‘s site showing the different sizes of trichomes.
Here’s some more nerdy stuff if you like to know the technical details.