Tim-ber !
Where do trees fit in our indoor plantscapes (Part I).
Have you heard? There’s a plant craze on. People will spend a fortune on a flimsy houseplant cutting, not even certain if there’re any roots in the soil, or any nodes that’ll yield new shoots. They spend $500 on a wee monstera import that got it’s variegated spots from a chemotherapy lab in Thailand. Or they’ll buy a trailing philodendron micans at the garden centre that’s $110, grown in a hot-house climate, and less than six months old.
In such a topsy turvy world you really have to pity the poor bonsai tree — repotted eleven times, watered fifty-six-hundred times, pruned a hundred-and-one times, fertilised three-hundred-and-eighty times — and sells for a measly $350. And in a $140 pot! A labour of love, it must be.
Yes, the plant world is upside down, but this isn’t the topic of this post (that one will have to come later). What I want to explore, rather, is the question of where do trees stand in our indoor plantscape? Or, put another way, should we think about, and treat, our indoor trees differently from our other indoor plants?
Consider setting aside ‘trees’ as a special category of indoor plants. This will free up your thinking about them, on how we should care for them differently, and how we can use them to diversify our indoor jungle.
Putting bonsais aside, you may have trees inside and not even know it, perhaps because you’ve never really considered a ‘tree’ as anything different from other indoor plants, or maybe because you don’t view some indoor plants as trees at all, although they are.
Some ficus trees would be candidates for this latter category. Do you have any rubber trees (ficus elastica), any fiddle-leaf lyratas, or maybe a weeping ficus benjamina? Certainly these are all trees — just plant one in a field somewhere, then come back years later and see what’s happened.
Other popular indoor trees include umbrella trees (schefflera), olive trees, coffee trees, and even citrus trees. Dracaenas and palms also grow into what are essentially trees, although I’ll exclude these here for reasons that will become obvious (here’s a link to a list of 30 indoor trees, loosely defined).
Now that we’ve covered the obvious — identifying our indoor trees as trees — we can turn to the more important point of asking, so what? The question is a good one and the answer has two branches. One has to do with the more practical side of things; the other has to do more with aesthetic considerations.
One of the unique features of (non bonsai) indoor trees is that they are, or will eventually be, tall enough to make a visual statement. It’s hard to fill up a huge or tall space — a foyer, a lounge, a warehouse office — with a fern or a snake plant. Even large-leaf philodendrons never get particularly tall.
Sometimes we need something tall and narrow, because we have more height than width (think: corner of the lounge, as above). Other times we want both. Depending on which of these fits your situation, you’ll need to make different choices. And this is when things get technical.
First, think ‘tree’ when you buy a tree. If necessary, ask someone: “Is this a tree? What’s its growth habit? While the future shape of a pothos might be obvious, trees are not so simple. At MONSTERA we’ve had several large schefflera trees in the store and all of them had to be heavily pruned back each season so as not to grow out of bounds. We wanted them shapely and smart, not ungainly and thus hard to sell.
The houseplant you buy is not going in the ground in the backyard, but still, you’ll want to consider what a tree is going to grow into long-term — once a tree, always a tree. Do you have room for it? Does it really belong indoors? What form do you imagine it taking? How fast does it grow?
Once you’ve acquired a trunked species, the usual tactic is to do nothing, which may yield good results for a time. In most cases, though, some intervention will be, if not required, certainly recommended. Even a few snips here and there can make a real difference as the years tick by.
Before indoor plants became all the rage, it was common to find people selling indoor trees online for a nifty price — because they’d outgrown their home. In other words, no intervention was taken by the owner, either in reducing the plant or raising the ceiling. 🙂 I once found on the berm a 20-year-old, two meter tall fiddle-leaf tree that’d been abandoned by a neighbour — probably it had grown “too tall.”
As it happens, there’s a reason this scenario crops up: it’s the manner in which trees destined for the indoors are propagated and sold. If a tree is nursery-grown to be an indoor plant, most likely it will never have been pruned. As a result, it has no branching. It’s just a beanstalk when you buy it and remains so seemingly forever. The rubber tree and fiddle-leaf ficus are common examples (see here).
Often in these cases, to make up for the lack of branching in juvenile trees, nurseries will achieve volume by selling multiple trees in a single pot. This only confuses things further. Not only is the possibility of branching obscured by the crowded group planting, now there’s no longer even room for branching.
Ultimately, having multiple trees in the same pot is a nonsense; eventually, you’ll want to take them out of the pot and pull them apart.
All of which is a long-winded way of saying this: we should want our indoor trees to branch out and get on with the business of looking like trees.
Fortunately, whether in a pot or in the ground, a tree responds well to pruning. For example, for the ficus species mentioned above, you can arrest the ‘beanpole’ habit simply by cutting off the growth tip (at the top). Not to worry, the tree will still grow, by shooting upward but also outward. If done during a warm and bright time of year, tip removal will activate hormones at dormant buds, causing nearby leafs to grow out as branches. Horticulturalists put it like this:
Dormant buds in these nodes [are] formed long before, and have a vascular connection to the cambium. The adventitious growth from these preformed buds can result in strong new branches, unlike the adventitious growth that originates from newly formed, adventitious buds. (A. L. Shigo, ‘A New Tree Biology Dictionary’)
There’s no great challenge in topping a tree, but there’s more too it than just reducing it’s height. Branching fills out a tree, which makes it look fuller and more appealing. As it does this, it also makes the tree sturdier. By sturdier I mean the relative thickness of the trunk increases, allowing it to eventually hold itself up.
It’s one thing to stake a trailing plant, to get it to grow up rather than down, but a tree really shouldn’t forever need a stake. There are no stakes in the forest, a fact that should alert us to the possibility that maybe we can grow our indoor trees so they’re stakeless too.
How does pruning lead to a thicker trunk? Consider the trunk on the Northland-grown fiddle-leaf ficus pictured earlier. The tree has been cut back many times, growing out and then being cut back, over and over. Meanwhile, as this happens, the trunk carries on growing, fatter and fatter. So the reason you might have a beanpole of a tree is because all of the energy is allowed only to grow upward (and upward). By contrast, once a tree is branching, energy goes up but also out. All growth contributes to the thickness of the trunk below, meanwhile, so the more branches we have, the more the trunk will thicken relative to its height.
This, by the way, is a fundamental principle in bonsai. It’s a common misunderstanding that a bonsai tree is dwarfed by virtue of living in a shallow pot, a kind of forced stunting akin to the old Chinese custom of foot-binding. In truth, the proportionally fat trunk on a bonsai is due to basic pruning. Nothing fancy: constant reduction of the terminal branches, including the leader, means most of the height is removed, whereas all the growth of the trunk still accumulates.
Perhaps not a pleasant comparison, but think of human obesity: an adult eats and eats but is not growing taller — only fatter. In the case of trees, however, this is what we want.
Probably a personal bias, but I think trees as indoor plants offer good value. While not all trees can live indoors, those that can present deeper possibilities for ourselves and our indoor jungles. What this ‘deeper’ means, and other aesthetic considerations, are the subject of Part II, to follow. Stay Dirt Wise.