Thigmomorphogenesis

How climbing plants respond to the world.

We walk, they climb..

If you've ever grown a vining plant, you may have noticed that they tend to move around a lot. This is because they are constantly looking for something to attach themselves to. Thigmomorphogenesis is the scientific term for the process by which plants respond to touch. Thigmotropism is the name given to the response of plants to physical contact. In this blog post, we will discuss what thigmomorphogenesis and thigmotropism are, and how you can use them to your advantage when growing plants!

Definitions

Let's take a second to break the words down with some plain english terms.

Thigmomorphogenesis

Thigmo - Movement
Morph - Change
Genesis - Beginning

Put everything together, and we have a word that describes a plant's ability to respond to touch stimuli.

Thigmotropism

Thigmo - Movement (but we already knew that)
Tropism - Direction

Combined, this describes a plant's ability to move or grow in a certain direction.

What's the difference?

Thigmomorphogenesis is the overrarching term that covers all touch related responses from plants.

Thigmotropism qualifies what a plant does after it is touched.

Aroids growing on support trellises.

Positive vs. Negative Responses

There are two main responses that a plant can have to touch stimuli.

A positive response would be if the plant moves toward the stimuli, and a negative response would be when a plant moves away from it. An example of a positive thigmo response would be a tendril wrapping around a trellis when it makes contact. If the plant moved away from the trellis, that would be a negative response.

Two types of plants that grow in different ways.

Real Life Examples

A few ways you may have noticed Thigmomorphogenesis in your collection or garden.

Tendrils

Have you ever watched a tendril move all on its own? Sometimes they can actually move fast enough to watch with the naked eye! This is the plant's way of making sure it doesn't miss anything it can grab on to.

Tendrils will wrap around any object they come in contact with, be it another plant, a wire fence, or even your finger! This is how plants are able to climb toward better light. This is sometimes frustrating to deal with when a viner is growing on another plant or part of your house where you don't want it.

Aroids

Philodendron, Monstera, and Pothos are all aroids, and as such, have Thigmomorphogenesis built into their growth habits. These plants are known for their aerial roots which help them climb. If you've ever tried to pot an aroid, you know that these roots like to find something to grab on to!

Aerial Roots

Aerial roots may look similar to tendrils, but they serve a much different purpose. They can grow small fuzzy mechanisms on the end that help them grab on to surfaces. These roots won't physically wrap around any object they come in contact with, but can still be very difficult to remove once they've latched on.

Internodes

An internode is the space on a plant stem between two nodes. These are the spots where leaves, branches, and flowers grow. Thigmomorphogenesis can cause plants to produce larger or shorter internodes when they come in contact with an object. 

Use it to your advantage

Our goal is to create a positive thigmotropism response in plants. There would be two potential goals that can be accomplished by leveraging plant responses to touch.

Directional Growth

Thigmomorphogenesis can be employed to make a plant grow in a specific direction, and the execution is super simple. Tying a plant to a trellis, or weaving it through the structure, will signal a plant to harden up where it currently rests. Keep in mind that any climbing plant will try to grow vertically from it's most recent internode. So if you are trying to get it to grow horizontally, you will need to tie off the nodes as they grow. Leap frog your ties one over the other and let the previous nodes rest on the trellis.

Grow Larger Foliage with Fenestrations

Here at Super Trellis HQ, our main "crops" are tropicals and aroids. Our main goal is pushing plants to maturity as quickly as possible. We want to see those big, mature, fenestrated leaves as soon as possible! We use some research from Jaffe to guide our processes.

Jaffe's research indicates, securing a climbing plant to ANY support at all will result in larger foliage with subsequent nodes. In plain terms, secure a stem to any support and the next leaves will be bigger. Yes this means a stake, trellis, or a pole. Anything will do as long as the plant is secure.

This doesn't necessarily mean that the entire plant needs to be secure, only one specific section. The two most recent internodes are the only two that actually need our attention when creating a positive Thigmotropism response. If these two nodes are tied off, the plant will be signaled that it can dedicate energy to foliage, rather than using energy to find support. Plants are very efficient at using their energy.

Wrap Up

One simple phrase to live by when growing climbing plants, "secure the plant to a support".

If your goal is to grow small foliage that stays small, don't follow this advice.

If you want bigger healthier plants, give them what they need!

In this post

Everything we used to make this happen.