Keeping Houseplant Clumps Alive

There are enough coffee seedlings (Coffee arabica) in this pot to start a small coffee plantation! Photo: mydomaine.com

You often find attractive clumps of leafy houseplants in garden centers: seven or eight small stems, or even more, all crowded together at the base. Whether you know it or not, you’re looking not at one plant, but rather a pot of seedlings all jammed in together. Or sometimes a cluster of plantlets issuing from tissue culture. 

They’re certainly pretty enough and it’s hard to resist buying one or two. The problem is, when you get them home, they soon stop growing or at least most of them do.

You see, they’re not happy plants. They’re very crowded, with no room to grow much further. Each plant is competing for vital growing space with its brethren: for room for their roots to expand, fertilizer for growth, adequate moisture and adequate space for their leaves to trap sunlight. Watering will become more and more difficult as time goes on, as there are far more roots than normal, all desperately trying to get their share of the moisture you apply. You’ll soon find they’ll dry out very rapidly, often only 2 or 3 days after a good soaking. It’s a true battle for survival of the fittest taking place on your own windowsill!

Some of these plants do eventually overcome this constraint … by eliminating the competition. One or two will manage to outgrow the others and then take over, continuing to develop while the others slowly die out. 

A few manage to keep the battle raging and will actually live together for years as they duke it out. Mostly, though, after a few months, they decline and begin to die. Or you check them one morning to find they have dried to a crisp overnight and nothing will bring them back!

Common Potted Seedling Varieties

The following plants are among many houseplants often offered as clumps of seedlings in garden centers.

• African mask or elephant’s ear (Alocasia spp.)
• Ardisia or jet berry (Ardisia humilis)
• Asparagus fern (Asparagus spp.)
• Buddhist Pine (Podocarpus macrophylla)
• Coffee plant (Coffea arabica)
• China doll (Radermachera sinica)
• Coralberry (Ardisia crenata)
• False aralia (Plerandra elegantissima, syn. Dizygotheca elegantissima)
• Grevillea or silk oak (Grevillea robusta)
• Japanese aralia (Fatsia japonica)
• Lucky bean plant (Castanospermum australe)
• Money tree (Pachira aquatica)
• Monstera or Swiss cheese plant (Monstera deliciosa, syn. Philodendron pertusum)
• Norfolk Island pine (Araucaria heterophylla)
• Parlor palm or neanthe bella palm (Chamaedorea elegans)
• Schefflera or umbrella tree (Schefflera actinophylla)
• Tree philodendron (Philodendron bipinnatifidum, syn. P selloum)

Interestingly, some of these plants won’t look much like their more mature selves. A seeding schefflera, for example, will have only simple leaves at first, then trifoliate ones, nothing like its umbrellalike adult leaves. Monstera seedlings have oval, uncut leaves and look so much like a philodendron many nurserymen often call them Philodendron pertusum, while the tree philodendron (Philodendron bipinnatifidum) will have heart-shaped leaves then arrow-shaped ones, nothing like its huge lacy adult leaves.

A few of these plants will even still have pits or seeds at their base when you first buy them and their stems may still carry their cotyledons (seed leaves), especially if you catch them shortly after they’ve arrived in the garden center, straight from the wholesale nursery that started them.

Why Offer Plantings So Crowded?

You have to wonder why nurseries offer such planned obsolescence plantings … and the answer is, mostly, because they look quite nice that way. A single seedling in a pot, although healthier in the long run, would have looked rather wimpy and forlorn on its own at that early stage of its existence. In a dense cluster, most of these clumps tend to take on an attractive rounded shape, all the plants blending together so you can’t really tell one from the other. 

Seeds of these plants are densely sown in plug trays, then transplanted into more saleable 4 to 6 inch (10 to 15 cm) pots shortly before shipping to garden centers, thus a lot of plants can be grown in very little space. This photo shows parlor palms. Photo: tropicalseeds.com

Another reason wholesale houseplant nurseries do this is that seeds are very inexpensive compared to starting plants from cuttings and the ones used are chosen from among plants that grow quite quickly. Most reach the stage of a saleable potted plant in just 6 months or so. So, they’re very profitable for the grower.

That the long-term results are likely to be disappointing to the end buyer doesn’t bother the growers in the slightest. The attitude in the horticultural industry has long been that houseplants are expendable, true throwaway items, and are only expected to last about 8 weeks in the home. (Read The Life Expectancy of Houseplants for more information on this subject.) If they die after that, you’re assumed to have gotten your money’s worth. Yet every one of the plants mentioned in this article could actually live for decades … if given space and reasonable care.

Can I Save Them?

Sure! Their main problem is overcrowding, so simply “un-overcrowd” them and all these plants will do just fine! In fact, there are three options for doing so: 

1. Thin’em Out

The easiest way to fix the problem is to thin them out. Just take a pair of pruning shears and—snip, snip, snip!—clip off the excess plants at their base. For most of them, like coffee plants (Coffea arabica), neanthe bella (Chamaedorea elegans) or China dolls (Radermachera sinica), leave two or three plants in the pot (but no more) to still have a bit of density, but others, like Norfolk Island pines (Araucaria heterophylla), scheffleras (Schefflera actinophylla) and lucky bean plants (Castanospermum australe), will eventually grow to be sizable indoor trees and yet others, like tree philodendron (Philodendrum bipinnatifidum) and monstera (Monstera deliciosa) into massive plants as wide as they are tall, and will really grow much more handsomely on their own, especially in the long term. 

If clipping the little plants down upsets your moral code (the goal being to kill them so the survivors can grow more healthily), consider rooting the cut stems in a small pot of soil set inside a mini-greenhouse. You won’t be able to root the neanthe bella palm (Chamaedorea elegans), though: it doesn’t take root from stem cuttings.

2. Divide to Conquer … While They’re Young!

Or you can separate the plantlets and pot them up individually or by groups of two or three. This is a more delicate operation, as their roots will be intricately entwined and there is a real danger of losing a few. But if you’re careful, you ought to be able to pull most of them through. 

?Helpful hint: Consider using some of the smaller seedlings as terrarium plants. They’ll eventually become too tall, but most can be trimmed back and kept tiny for a number of years.

You could simply unpot them and pull the plants apart, or cut between them with a sharp knife to separate them, but there is also a softer way. Unpot them again, but this time, set the shared root ball in a bowl of water and leave it to soak for a few hours, even overnight. Much of the soil will fall away, helping to free the roots. Very often the plantlets will begin to come apart all on their own or at least will be easier to separate, slipping apart if you just tug lightly on them.

Then pot them, probably putting each division into a pot about the same size as the original one, making sure you set them so they’re at the same level in soil of the new pot as they were in the original pot; certainly no deeper. Just use regular potting mix.

You have to do this while the plants are still young, though. If you wait too long, their root systems become so entwined it may be impossible to get them apart without damaging them. 

3. Pot Up

The third possibility is to simply repot the whole clump into a larger pot. They’ll still be crowded and their growth will likely remain considerably inhibited, but at least the peripheral roots will have room to grow and that will allow them to grow somewhat. Over time the weaker ones will likely die, though, but then you can just cut them out. 

You’ll discover crowded plantings like this will need to be repotted quite frequently, probably every year. Whenever you start noticing the soil drying out too quickly after a thorough watering, it will be time to move them into a pot a size or two larger. And they’ll always remain fragile to underwatering.

Caring for Houseplant Clumps

In this cluster of buddhist pines (Podocarpus macrophylla), a few of the plants are starting to take over and the others will likely die. Photo: interiorplants.ca

Houseplants sold as clumps of freshly germinated seedlings are of widely different species and you wouldn’t think they’d have much in common, but in fact, they’re mostly in the “average care” group. They need bright to medium light, even full sun in winter, high air humidity (you may need a room humidifier to help them through the winter months), moderate fertilizing spring through early fall and normal indoor temperatures. 

Until you’ve given them a decent mass of soil to grow in, they’ll need careful monitoring when it comes to watering. Whenever the soil begins to dry on the surface, you’ll need to water them well with tepid to room temperature water. That can easily be more than once a week, especially if they grow in intense light and dry air.

When all is said and done, you’ll likely have half a dozen or so pots of cute little, happy, healthy plants to share with friends and family. Not a bad accomplishment, wouldn’t you agree?