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?
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.
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.
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.
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.
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?
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.
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!