Climbing Plants Like to Climb

Standard
201701311A.jpg

This dangling heartleaf philodendron (Philodendron oxycardium) will produce smaller leaves than a climbing one.

That climbing plants like to climb may seem like a fairly obvious statement, but bear with me: it really isn’t.

You see, we like to grow climbing plants (plants that mount trees, treillises, walls and other tall objects), especially climbing houseplants, in hanging baskets, with their stems dangling downwards. They certainly look pretty enough grown that way… but they don’t much like it.

Many will start to produce smaller and smaller leaves the longer they dangle. That’s the case of most aroids, including philodendrons and pothos, as well as many Cissus. Sometimes they stop producing leaves entirely, producing only a lengthening green stem. Others just stop growing after they’ve dangled for a while or refuse to bloom on any stems that trail. That’s the case for morning glories (Ipomoea spp.), for example.

201701311C.jpg

Try growing a morning glory as a hanging plant and it will try growing upwards, wrapping itself around its own stems.

Of course, many climbing plants will fight tooth and nail against dangling. The afore-mentioned morning glories will quickly start to twine back up around their own stems in an effort to grow upwards again. If you won’t let them, untangling their stems so they trail further, they will stop growing and certainly won’t bloom.

This reaction is due to hormones called auxins present in their stem tips. They concentrate in the uppermost part of the stem and stimulate growth. When the plant hangs in what is essentially an upside down position, the auxins become diluted and growth decreases or ceases.

Finding a New Support

In the wild, when a hanging plant becomes disconnected from its support, it will often trail downward to the ground, producing increasingly smaller leaves, then its stem wanders off across the soil until it finds a new support it can climb.

201701311D.png

A climbing plant will seek out something dark on which to climb.

At this stage, it will actually grow away from the light, an action called negative phototropism, normally a most unplantlike thing to do. But there is a method to this madness: deep shade can be caused a tree trunk or other upright object it might want to climb on. And it desperately wants to climb.

So off the stem heads towards the darkest thing around. Once it finds it, it starts growing upward again, takes up positive phototropism like any normal plant, and soon its leaves start become bigger again. Happiness at last!

When Climbing Plants Do Climb

If you switch techniques and allow your climbing plants to climb, perhaps up a trellis, a moss pole or a wall, rather than trail from a pot, many will do some striking things. Many aroids (philodendrons, pothos, monsteras, etc.) will begin to produce larger leaves — much larger leaves — when they climb. And much thicker stems too.

201701311B.JPG

Huge healthy leaves on an upright-growing heartleaf philodendron (Philodendron hederaceum)

Did you know your good ol’ heartleaf philodendron (Philodendron hederaceum, syn. P. oxycardiumP. scandens and P. cordatum), whose leaves are often barely 2 inches (5 cm) wide when it trails, is capable of producing leaves 1 foot (30 cm) in diameter when it climbs?

201701311E.jpg

If it weren’t for the yellow marbling, you’d scarcely recognize the huge, deeply cut leaves and thick stems of this pothos (Epipremunum aureum) as those of the popular houseplant.

And that pothos (Epipremnum aureum, syn. Scindapsus aureus) growing half neglected in the corner does the philodendron one better: at maturity (that is, when it grows upright and gets decent light [also a factor in leaf size]), not only do its leaves grow to enormous sizes, up to 40 inches by 18 inches (1 m by 45 cm), but they become deeply cut, like those of a monstera.

This increase in leaf size is also linked to sexual maturity: once they reach their full leaf size, these aroids will start to bloom and produce seeds. You thought philodendrons and pothos simply didn’t bloom? Try growing them up a tree in a tropical climate (most rooms aren’t tall enough to get them to flowering size) and they will bloom.

201701311F.jpg

Mature leaves and fruit on a creeping fig (Ficus pumila).

Other climbers keep producing small leaves as they climb, leaves that don’t change in size at first, often not for years. Then, when they’ve climbed high enough, they suddenly switch from this juvenile form to their mature form, with much larger leaves often of a very different shape and they too start to bloom and produce seeds. True ivies (Hedera spp.) do this, as does the creeping fig (Ficus pumila).

Some Climbers Don’t React

201701311H.jpg

Hoya carnosa is one climber that doesn’t seem to care which way it grows. Even hanging stems will bloom!

Not all climbers react badly to dangling. I’ve never seen a wax plant (Hoya spp.) that seemed to mind whether it was growing upwards, downwards or sideways, for example.

201701311G.jpg

Wandering jews (here Tradescantia zebrina, syn. Zebrina pendula) are natural trailers and don’t mind a bit of dangling.

And then there is the case of creeping plants we use in hanging baskets, like wandering jew (Tradescantia sp.) and Swedish ivy (Plectranthus). Although we might mistake them for climbers, they aren’t really aren’t: in nature, they’re groundcovers, wandering sideways, rooting as they go and forming carpets on the ground. They grow and bloom perfectly when you let them hang and even if you force them to grow upwards by fixing them to a support, that won’t change their leaf size or habit.

The same is true of epiphytic plants (ones that grow on tree branches), like the lipstick plant (Aeschynanthus spp.) and the goldfish plant (Nematanthus spp.). They look great in hanging baskets because they naturally arch outwards and downwards and are perfectly happy to bloom this way. But they aren’t true climbers.


Most true climbers will react positively if you allow them to grow the way Mother Nature intended them to do: upwards.

Try it and see!201701311a

Green Up a Wall with Creeping Fig

Standard
OLYMPUS DIGITAL CAMERA

Creeping fig used as an indoor wall cover.

Everyone knows you can grow climbing plants – Boston ivy, Virginia creeper, climbing hydrangea, etc. – on outdoor walls. After all, the term “ivy league university” comes from the way Boston Ivy covers so many of the buildings on university campuses. But have you ever considered letting climbers cover your indoor walls as well?

There are actually several houseplants that produce aerial roots or adhesive pads and can thus cling to walls. This group includes heartleaf philodendron (Philodendron hederaceum, formerly P. oxycardium), pothos (Epipremnum aureum), monstera (Monstera deliciosa) and English ivy (Hedera helix). Most are of these sold as hanging basket plants and normally allowed to drip downwards from their pots, but in the wild, they usually grow upwards, clinging to tree trunks or rocks… or buildings. Why not use them that way indoors?

Personal Experiences

20151030D

Creeping fig covering a column in Longwood Gardens’ Main Conservatory.

I’ve experimenting with creeping fig (Ficus pumila) as an indoor wall cover for about 35 years. I’d seen it used as a wall climber in several public greenhouses, notably in Longwood Gardens and Meadowbrook Farms in Pennsylvania and in the Royal Greenhouses of Laeken in Brussels, not to forget in the sales area of Logee’s Greenhouses in Connecticut. I feel it is a better choice than many others because of its denser growth habit and natural tendency to branch freely. Plus, with its tiny leaves growing one practically on top of the next, like shingles on a roof, it’s simply very attractive when grown that way.

I first I tried growing it on walls in various apartments over the years, but usually ended up moving before it got very far. Then, at my current address, I let it grow up a wall in my dining room over a 4-year period. I thought the result was really quite outstanding… but then I lost the plant (the person entrusted with watering all my plants while I was away forgot to water that one). It was quite a shock to arrive home and see a shower of yellowing leaves dropping from the walls and ceiling! In spite of a careful attempt to revive it, it didn’t recover and I had to remove it.

20151030B

My creeping fig in late October 2015.

I reinstalled a creeping fig in my dining room 7 years ago and you can see the results in the photo. It grows on two walls and across the ceiling. No, it doesn’t cover the entire surface (far from it!), but it has this zigzag growth habit, a bit like a Roomba, hitting an obstacle, then heading off in another direction, so I’m hoping to see more wall coverage over time.

The leaves of this plant are tiny and press against the wall or ceiling, with the result that several guests thought I’d painted a climbing plant on the wall.

Actually, I also have another creeping fig climbing up the inside walls of my fireplace… but that’s another story.

How to Grow a Creeping Fig Wall

You’ll first need to choose a wall for your creeping fig to climb on. It can cling to almost any surface, even plaster abundantly coated with multiple layers of paint (my situation). Creeping fig will grow under most light conditions, from bright sun to deep shade, although it grows much faster in a sunny spot. Obviously, too, the room must be heated because the creeping fig tree is a subtropical plant. It will take temperatures nearly down to freezing if necessary… but that’s not likely to be the case in an indoor situation.

20151030G

Creeping fig as it looks when you buy it.

When you find the suitable spot, you’ll need to locate a plant. That shouldn’t be too difficult, as creeping fig is often sold in garden centers as a foliage plant or in a hanging basket. If you can’t find it locally, try a mail order houseplant source, like Logee’s in the United States or Understory Enterprises in Canada.

Since your creeping fig will be growing in the same pot for the rest of its life (I don’t see how you’d ever be able to repot a plant that clings to a wall!), you’ll want to repot it right away into a large container (I used an extra wide, extra deep window box). Any houseplant potting mix ought to do. Once you’ve potted it up, place the container against the desired wall… and wait.

There is no use trying to force the plant to climb by gluing or tacking its creeping stems to the wall yourself. I’ve tried it and they’ll only fail to thrive. Instead, let Mother Nature take care of the situation. When the plant is ready to climb, and that can take several months, one or more of its stems will grow towards and then up the wall all on its own, clinging to the surface thanks to tiny aerial roots.

20151030F

Pinch the stems for denser growth.

The stems can climb fairly quickly once they get started: a foot (30 cm) or so a week. Initially the stems head towards the ceiling, so you quickly gain height. Side branches are slower to appear. They tend to grow more horizontally, at least at first, and also grow more slowly than the upright ones. If you want dense growth from the start, pinch the upright stem and repeat as needed: this will slow the growth rate of the plant, but at least will force it to branch more profusely.

How long before your fig tree completely covers an indoor wall? It might well be decades! My current plant has been growing 7 years and covers only a small portion of the room, but then it’s in a very shady location with no direct sunlight. The kind of place where most houseplants that would kill most houseplants. In a bright sunny room, growth will be many times faster.

Basic Maintenance

Creeping figs prefer evenly moist soil. Before watering, insert your index finger into the soil. If the soil feels dry to the touch, it’s time to water. Do this once every 4 to 5 days in a sunny or hot room, once a week or so in a darker or cooler one.

Other than watering, creeping fig requires little maintenance. You can feed occasionally with diluted fertilizer, but it’s not a heavy feeder.

As for pruning, you’ll want to control where the plant goes, as it will wander pretty much anywhere if you let it. I try to restrict mine to the dining room only and snip off any branches that head elsewhere. There doesn’t seem to be an off-season: the plant grows by fits and starts throughout the year.

Occasionally some of the leaves turn yellow, then brown. This seems mostly linked to irregular watering. To avoid it, try to keep the soil at least somewhat moist at all times. If some leaves do turn brown, gently knock them off with a duster or a broom.

Can You Expect Fruit?

20151030H

The curious fruit of the creeping fig isn’t likely to form indoors.

The creeping fig most indoor gardeners are used to, with tiny leaves and thin stems that cling to various surfaces, is the juvenile form of the plant. At maturity, it completely changes its appearance, producing thicker, shrubbier branches that arch out from the wall and much larger and thicker leaves. The plant is then able to produce its curious green fruit… but they won’t ripen indoors. They need to be pollinated by a specific insect, a tiny wasp called Blastophaga pumiliae, and you certainly won’t have any in your home. At any rate, creeping figs grown indoors, where the light levels are usually quite low, rarely produces mature branches.

Other Varieties

20151030I

Oak-leaved creeping fig.

I’ve only ever tried using the original form of creeping fig (Ficus pumila) on walls, that is, the species itself. There are also cultivars with variegated foliage or smaller leaves you could try. I particularly like the oak-leaved creeping fig (F. pumila quercifolia), with small lobed leaves, but it is not as resilient as the species, so I’ve never dared to use it to cover a wall. I use it more as a ground cover for terrariums and bonsais.

Is There a Fig-covered Wall in Your Future?

Why not? It’s an interesting long-term project and certainly original. There probably aren’t more than a handful of private residences in all of North America with indoor walls covered in creeping fig, so you can literally claim your wall is one in a million! I say if you like the idea, go for it!