As is often the case, I asked myself a question and, finding the answer fascinating, I’m sharing it with you. My question: how does a plant cling to another plant and “climb” it?
Well… plants grow upwards, eh…
Yes, but how does it hold up? Without being repelled by wind, rain or animals? The advantage of growing on a host is quite logical: more light at height, better visibility for pollinators, better seed dispersal, etc. All without having to build a big, strong, long trunk. All without having to build a big, strong trunk that takes a long time to grow. It’s a strategy that certainly pays off.
But just to marvel at the “how”, and also perhaps to help you choose the right stake for your plant’s climbing strategy, here’s an overview of some of the ways plants climb rocks, trunks and homes.
The Stem That Twists
Some plants, like beans, have a main stem that grows naturally like a corkscrew. The horticultural term is a climbing plant with a voluble stem. It twists in all directions as it grows, and when it encounters an obstacle at the end of its stem, it clings to it. It can then wrap itself around it, but not very tightly. In a loose mesh, the stems could snake from hole to hole, but in a too-tight mesh, it’s more difficult. Often, these plants end up forming a kind of thick braid of stems when they use each other for support.
The Tendril
I love these plants with their tendrils. I think they’re elegant! Who doesn’t love the look of a beautiful vineyard, eh? They’re excellent climbers on tight or wide fences, precisely because of those little stems that twist around anything. Make sure you have a thin enough support (4mm, 3/16″): the little stems won’t go all the way around a 2×4! Once again, watch out for knots: when several tendrils wrap around each other, it’s impossible to untangle them. If you don’t want to have to cut off a part of your plant that has grown over your fence gate, intervene quickly to direct its growth in another direction.
Depending on the species, tendrils may form in the axils of petioles (transverse branch), as in peas, but in other species, the branch itself may form the tendril before growing leaves.
The Thorny
Other plants use their thorns to hold on and climb. They’re not the best climbers: your climbing roses will probably need your help to cover a wall or fence in an elegant way. Indeed, thorns aren’t really for “hanging on”, but rather for rising above obstacles. By obstacles, I mean rocks or trunks, but not a smooth wall. Often, when left to their own devices, these plants form a more or less loose tangle of branches. Over the years, the mound grows with the accumulation of new thorny branches. If you have wild brambles, you know what I’m talking about!
The Adhesive
In my opinion, this is the most original strategy. Some plants are able to grow an ultra-specialized stem at the end of which are… suction cups. Some even produce a sticky substance at the end of these little discs, which adheres to the smoothest surfaces and enables the plant to rise effortlessly. As a result, Virginia creeper can cover a wall, fence or even a metal post with ease.
Although these suction cups are not harmful, they can be very difficult to remove, and can even leave indelible marks on their support. What’s more, when the plant reaches a considerable size, we recommend installing a cable to secure it. Indeed, as the primary stem thickens and becomes a woody trunk, the adhesive can break, leaving only the young stems at the top to bear the full weight of the plant. In the event of strong winds, your pretty plant wall could be torn from its support.
The Clingers
It’s very similar to the adhesives: it, too, clings to any surface without a stake and, when mature, may need a cable to secure it. Where it differs is in the way it clings: it uses aerial roots, sometimes microscopic, to anchor itself in the slightest interstice. However, these plants have the disadvantage of causing damage in certain cases. When the root, which was tiny at the outset, widens as the plant grows, it can break the interstice into which it originally squeezed.
I hope that with all this you’ll be able to better understand your climbers and find the ideal support for them. Always pay particular attention to the weight of your plant: I’ve tipped and even collapsed a few stakes that were a little too weak for my beans and zucchinis!
Hey, wait! It says part 1 in the title!
Aren’t you observant! Here’s a sneak preview of the title of next week’s article: Hanging On: Epiphytes (part 2). See ya!
I loved this. Thanks. I find vines fascinating.