Can Two Houseplants Share One Pot?

Standard

 

20171216A  gallery.yopriceville.com.jpg

Can two houseplants share one pot? Source: gallery.yopriceville.com, Clipart Library & beautifulgarden.org.uk

Question: I grow two avocado trees in huge pots. I wondered if it would be possible to plant my aloes in the same pots, at the foot of the avocados? That would save a lot of space and it seems to me that the effect would be very attractive. What do you think?

Dominique

Answer: Your question brought up an interesting thought. Why is it that we traditionally grow each houseplant in an individual pot? After all, we don’t do so outdoors. We regularly mix and match plants in flower boxes and containers, in flower beds as well. Yet with houseplants, it’s usually: one plant per pot, even though there is no logical reason we couldn’t mix houseplants together too: it’s just a question of long-standing habit.

Compatibility is the Issue

Of course, the secret to success with mixed pots is that the plants have to be compatible, with similar or identical needs.

20171216C statebystategardening.com.jpg

This mixed container is doomed to fail. The poinsettia and Norfolk Island pine could share a pot, since they have similar needs, but the selaginella (the mosslike plant) requires high soil and air humidity that others can’t handle. Source: statebystategardening.com

You’d have a hard time keeping a desert cactus, which prefers full sun and soil that dries out thoroughly between waterings, and a maidenhair fern, which prefers moderate to low light and soil that is constantly moist, happy in the same container. Nor should you try planting together strong, invasive plants with slow-growing or fragile ones, plants that need a long period of dry dormancy with plants that grow year-round, plants that require a lot of fertilizer with plants that prefer nutrient-poor soil, nor plants that differ in soil type, temperature, light needs, etc.

20171216B Alina Zienowicz, WC.JPG

Kalanchoe daigremontiana gives off products that can actually poison the plants it grows with. Source: Alina Zienowicz, Wikimedia Commons

There are even allelopathic houseplants (Kalanchoe daigremontiana, for example) that render the soil in which they grow toxic to many other plants and are therefore never good buggy buddies.

That said, there are many houseplants that actually do share many of the same requirements. So many common varieties like or at least tolerate average light, average air humidity and average watering—philodendrons, scheffleras, spathiphyllums, etc.—and therefore, unless they have some other incompatibility, could certainly share a pot.

20171216D The Urban Wife. png.png

Succulents can usually share a pot, but if you add cacti, you’re asking for trouble! Source: The Urban Wife

Nor is there any problem growing most succulents, such as sedums, aeoniums, euphorbias, crassulas and echeverias, in the same pot, since almost all like full sun, tolerate dry air and prefer soil that dries out between waterings. But if you add a desert cactus to the mix, even if this is currently done commercially (unfortunately), it often leads to disaster, as least in the long run. That’s because most cacti really only do well with a long winter dormancy under cool, dry conditions, while “other succulents” usually don’t like things quite that cold and dry.

In other words, combining different plants in one pot is possible, but it can be complicated.

Your Combination

20171216AB  gallery.yopriceville.com copy.jpg

Can aloes share a pot with an avocado? Source: gallery.yopriceville.com, Clipart Library & beautifulgarden.org.uk

At first glance, the combination you suggest would not seem doable. The avocado (Persea americana) is a tree native to the tropical rainforest (i.e. jungle) and prefers soil that is always at least a bit moist, plus high atmospheric humidity at all times. The medicinal aloe (Aloe vera), on the other hand, comes from an arid environment, where the air is dry and the soil receives no water for months on end. Growing them together would seem to be a really bad idea.

That said, the aloe is an extremely adaptable plant, much more so than the avocado. It’s been grown as a potted plant for almost 6,000 years and seems to have learned to live with human vagaries. Yes, it prefers sun and soil that is on the dry side, but will adapt to medium or even low light and soil that is never totally dry, although you can’t leave it soaking wet for weeks at a time. Although it was designed by nature to tolerate dry air, it doesn’t require it and it won’t react badly to the efforts you put into keeping the much more finicky avocado happy. And both do like warmth year round, so they have at least one thing totally in common.

So yes, I think you could grow both together. It’s a borderline combination, but as long as you watch your watering and let the soil nearly dry out before you water, you ought to be able to let aloes share the big pots of your avocados.

Houseplant Weeds

Standard
20170116a

Kalanchoes (here K. daigremontiana) readily invade neighbouring pots and can be quite the pests!

You thought that by moving indoors to garden you were leaving the world of weeding behind? Well, think again. Like the weeds of our gardens and lawns, there are both weedy houseplants and houseplant weeds, plants that ready spread from pot to pot, seeking to take over the main plant’s space. And they really aren’t that rare. If you grow houseplants, you probably already know some of these plants already.

Guilty Parties

Here are a few of the plants that are often weeds indoors.

Kalanchoe

20170116b

Baby plants crowd the kalanchoe’s leaf margin and readily come free.

Several kalanchoes (Kalanchoe daigremontiana, K. pinnata, K. laetivirens, etc.), all once formerly included in the genus Bryophyllum, have the curious habit of producing plantlets along the edge of their leaves. That is just soooo cute! And it gives you plenty of babies to share with your friends… but the babies readily “jump” into the neighboring pots and set up shop. They don’t actually jump, of course, but fall or get knocked free. Even so, when the pot next store fills up with the no-longer-quite-so-cute adolescent kalanchoes, there will be quite a bit of weeding to do.

Worse yet, kalanchoes are allelopathic: that is, they release toxic products that harm the plants whose pot they share. Thus, the desired plant grows less vigorously or may even die.

It’s better to put “jumping kalanchoes” in their place and not let them spread around indiscriminately!

Purple Shrimp Plant

20170116c

Purple shrimp plant (Porphyrocoma pohliana)

This is a charming little houseplant in the Acanthaceae family with an as yet unresolved botanical name (Porphyrocoma pohliana and Justicia scheidweileri are on the short list). It’s certainly pretty enough, with shiny leaves highlighted by silver veins and a long-lasting red “cone” at its top from which the more ephemeral purple flowers appear.

This one just showed up in my plant collection one day, undoubtedly having hitched a ride in another plant’s pot. Now I find it all over the place.

Polka Dot Plant

20170116M.jpg

Polka dot plant (Hypestes phyllostachya)

The polka dot plant or freckle face plant (Hypoestes phyllostachya), likewise in the Acanthaceae family, is a low-growing mound-forming plant with leaves dotted with spots and splotches in white, red or pink, sometimes to the point where there is little green visible, and likewise self-sows. The inconspicuous flowers often go sight unseen, but the baby plants that pop up here and there are much more readily visible.

Spider Plant

20170116d

Flowers of the spider plant (Chlorophytum comosum)

Who doesn’t know the spider plant (Chlorophytum comosum) with its long arching stolons (in fact, flower stems) bearing baby plants? However, unlike the kalanchoe, the babies aren’t normally invasive unless they happen to touch a pot of moist potting soil, as they don’t break free on their own. Instead, it’s the fairly insignificant small white flowers that produce pods of small black seeds that lead to small spider plants popping up in neighboring pots. They’re helped along by the fact that most people grow spider plants in hanging baskets, so their seeds can readily drop into any pots below.

Do note that any seedlings produced are all green, never bearing the cream to white stripes typical of most spider plant cultivars.

20170116e

Orange spider plant (Chlorophytum orchidantheroides)

C. comosum is not the only spider plant that self-sows a bit too vigorously. The orange spider plant, confusingly known by several names, including C. orchidantheroides, C. amaniense and C. orchidastrum, sometimes modified by the cultivar name ‘Fire Flash’, can also be invasive. Nothing like its grasslike cousin, it forms a rosette of fairly broad leaves with an orange petiole and midrib and does not produce hanging stems. Still it blooms readily and its seeds can jump from pot to pot.

The same also goes also for the large-leaved spider plant (C. macrophyllum), another rosette type with large green leaves. It is, in fact, the most invasive of the three.

Madagascar Jewel

20170116f

Madagascar jewel (Euphorbia leuconeura)

Most of the succulent euphorbias (Euphorbia spp.) stay in the pots you planted them in, but there is one exception: Madagascar jewel (Euphorbia leuconeura), with an erect swollen stem, eventually quite treelike, and oblong leaves with white veins, at least on young plants. The flowers are insignificant, but produce a seed pod that “explodes” at maturity, launching seeds in all directions, up to 15 feet (5 m) from the mother plant.

You often find this euphorbia in plant exchanges: people who have one always have plenty of babies to give away!

Grendelion

20170116g

Grendelion (Dorstenia foetida)

This truly bizarre (and frankly, none too pretty) succulent in the fig family, Dorstenia foetida, produces one or more uptight succulent stems with a bulbous base and intriguing flat shieldlike flowers looking vaguely like a green sunflower. It too launches its seeds everywhere.

Umbrella Palm

20170116h

Umbrella palm (Cyperus alternifolia)

Also called umbrella sedge and umbrella papyrus, the umbrella palm (Cyperus alternifolius) is a popular grasslike houseplant that grows best when left constantly soaking in water. It has a characteristic whorl of narrow leaves at its stem tips. Under good conditions it produces a profusion of pale green flowers that turn brown over time and these release light-as-air seeds that germinate in nearby pots, producing little plants that look just like tiny clumps of grass at first.

Artillery Plant

20170116i

Artillery plant (Pilea microphylla)

The artillery plant or artillery fern, Pilea microphylla, is not a fern, but the arching stems bear tiny leaves and flowers so small that you can scarcely see them without a magnifying glass. That doesn’t prevent it from invading the pots of other plants through its extra-tiny seeds, though!

Creeping Woodsorrel

20170116j

Creeping Woodsorrel (Oxalis corniculata)

This trifoliate plant with yellow flowers (Oxalis corniculata) is strictly a weed: no one would ever think of growing it on purpose. Even so, this small Eurasian weed somehow made its way into commercial greenhouses at some time in the distant past and is now a common houseplant weed worldwide, especially in pots of cactus and succulents. It isn’t too strict about C&S plants though, and will move in on any of your houseplants if you don’t ruthlessly yank it out before it produces seed.

Ferns

20170116O.jpg

Holly fern (Cyrtomium falcatum)

Ferns produce lighter-than-air spores and therefore can travel through our homes on air currents. They can land anywhere, although most need moist conditions in order to sprout. They love my basement where I find them growing in many pots, especially in seed trays, where the high humidity is much to their liking. Among the species suffering from wanderlust are holly fern (Cyrtomium falcatum), ladder brake (Pteris vittata) and maidenhead ferns (Adiantum raddianum and others).

Whisk Broom

20170116N.jpg

Whisk broom (Psilotum nudum)

This bizarre plant (Psilotum nudum) has no roots or leaves, only thin green upright branches that fork repeatedly and a creeping underground rhizome. Bunched together, the branches can be used as a small broom, whence the common name. Long classified as a fern ally, the whisk broom was recently determined to be a true fern, albeit a very primitive one. Its spores are carried about by moving air. Oddly, they germinate underground (most ferns germinate on the soil’s surface) and start their life as a parasite on soil fungus, a very unfernlike habit indeed.

Mosses

20170116k

Mosses in a flower pot

Yes, mosses also settle in our houseplant pots, most probably brought in from outdoors by the wind, as their spores are so small they can easily slip through window screens. Mosses mainly tend to appear in soil that is on the moist side, such as in pots of seedlings, but you’ll even find them in cactus pots.

Personally, I just let mosses grow: they create a nice green carpet that hides the soil from view and don’t harm their host. Terrarium lovers too enjoy mosses and often install various types in their miniature gardens.

Liverworts

20170116l

Liverwort (Marchantia sp.)

Liverworts (Marchantia spp.) are closely related to mosses, but they’re much less welcome than mosses when they show up in pots. That’s because they form soil-hugging carpets so dense that the soil’s air circulation is compromised and that can lead to the pot’s main inhabitant to suffer from root rot. To get rid of liverworts, scrape off a ½ inch (1 cm) layer of potting mix and replace it with fresh soil. Be careful how you water, too, as the presence of liverworts often indicates overwatering.


If you grow houseplants, sooner or later you’re bound to find one or more of these invasive plants in your pots. It’s up to you to decide whether they are enemies to eliminate… or cute new plants that deserve their own pot!20170116a

Hand-me-down Houseplants

Standard

20160120AWhen you visit any garden center or even one of those big box stores, there is always a houseplant section, but, most discouragingly, they all sell essentially the same plants. However when you visit people’s homes, you’ll often see houseplants that are never (or hardly ever) offered in local garden centers. If you ask about them, you’ll likely to hear a long and fascinating story, for many of these commercially unavailable houseplants have been handed down in the same family for generations, came from a cutting offered by an old friend or were picked up in a flea market or at a plant exchange.

Most of these hand-me-down plants used to be grown commercially, but disappeared from the market ages ago. Why? My theory is that, because they are practically unkillable and they are already found in so many homes, they were no longer marketable. Either that, or plant nurseries have simply so totally forgotten about them that they don’t even know they exist. Ask around the next time you’re in a nursery and you’ll see. These plants are commercially extinct.

Ask whether anyone has one at your local horticultural society meeting, however, and it’s an entirely different story: hands will fly up! These plants are all immensely shareable and therefore you’ll soon find inundated in cuttings and divisions.

A Definition

For me, for a houseplant to be a true hand-me-down, it has to have been around for a long time: at least 30 years. And it should be absent from regular garden centers. That’s why I automatically eliminate the spider plant (Chlorophytum comosum ‘Vittata’) from the list, even though yours may actually be a hand-me-down. There is no real sense of saving it for further generations, as it is still widely available from just about every plant merchant. The same goes for the famous heartleaf philodendron (Philodendron hederaceum, generally known by its former name, P. scandens oxycardium). It was introduced in 1936 through the Woolworth store chain and, while it may be that you think the specimen you inherited from your great aunt Elise is at least 70 years old, it’s also quite likely she bought it in 2002, so widely is this plant still available. And the same goes for the various dracaenas (Dracaena spp.), pothos (Epipremnum aureum), rubber trees (Ficus elastica), jades (Crassula argentea), wax plants (Hoya carnosa), clivias (Clivia miniata), dieffenbachias (Dieffenbachia spp.) and so many others. Yes, possibly you can trace your plant back as far as Noah’s Ark, but if it is still commonly sold, it is not of any great historical value.

A Few Hand-me-down Plants

What follows are examples of houseplants that truly have been passed from one generation to another for a long time and are almost never offered commercially any more, at least that is outside of mail order nurseries specializing in ususual houseplants. When you have one of these plants, you almost have a moral obligation not only to keep it going, but to ensure its continued survival by sharing it with others.

Three Begonias with a Long History

Let’s start with begonias, as so many of them fall into the hand-me-down plant category.

20160120B

Begonia x erythrophylla

The beefsteak begonia (Begonia x erythrophylla) is among the first hybrid begonias ever produced, introduced in Germany in 1845. With its shiny, waxy, rounded leaves of a delicious red wine color, its pink flowers during the winter (when you need flowers the most!) and its somewhat pendant habit due to creeping rhizomes that come to hang down outside of the pot, it makes an excellent choice for hanging basket.

20160120C

Begonia x ricinifolia ‘Immense’

Begonia ‘Immense’ (B. x ricinifolia ‘Immense’) is certainly aptly named. With its large green somewhat asymmetrical star-shaped leaves that can measure up to 3 feet (90 cm) in diameter, this 1847 hybrid stands out from the crowd. Equally curious are the whorls of hairy red scales that swirl around the petiole (leaf stem). It produces a thick creeping rhizome and blooms in the winter, producing clusters of small pale pink flowers.

These first two begonias can be propagated by rhizome cuttings, but also by leaf cuttings and even leaf section cuttings, making sharing them extra easy.

20160120Djpg

Begonia ‘Lucerna’

The original angel wing begonia (Begonia ‘Lucerna’ [‘Corallina Lucerna’]) was hybridized in Switzerland in 1892 and is still widely distributed… at least non commercially. With its upright stem, its wing shaped leaves prettily spotted with silver and its drooping bright pink flowers in summer, it doesn’t look much like its cousins. This begonia is propagated by stem cuttings.

There are more hand-me-down begonias out there: begonias are truly a group of plants with staying power!

Walking Iris

20160120E

Neomarica northiana

The walking iris (Neomarica northiana) is also called the apostle plant, as it is said that each segment must have 12 leaves before it will flower. It was introduced in the 1920s. It is indeed an iris relative and certainly looks the part, with its sword-shaped leaves and its short-lived blue and white flowers with the usual iris standards and falls. The flowers seem to emerge directly from a leaf that continues to grow in length after the blooms stop. Eventually a baby plant forms near the end of the stem, pulling the stem downward and making it a very curious hanging plant. I regularly see this plant in people’s homes, but almost never in garden centers.

Queen’s Tears

20160120F

Billbergia nutans

You rarely see this bromeliad (Billbergia nutans), with its tight rosettes of very narrow, almost grasslike leaves growing in dense clumps, other than in botanical gardens… and private homes. In the 1930s, however, it was a very popular Christmas plant because it blooms naturally at just the right season. And it is a tough-as-nails plant, easily tolerating almost the entire range of indoor growing conditions. It bears pendant stems covered in bright pink bracts while the actual blooms drip down as if they are crying, giving its common name queen’s tears. The flowers are not as colorful as the bracts, being a more mundane green with deep purple margins.

This is a great plant for people who want to try bromeliads, but aren’t patient enough to wait the 3 to 6 years most take to rebloom. Queen’s tears produces a mass of pups and matures rapidly, so there always a few plants in bloom every year just in time for Christmas. The numerous pups also means it can readily be multiplied for exchange purposes.

The True Christmas Cactus

20160120G

Schlumbergera x buckleyi, with hanging stems, is the real Christmas cactus.

The true Christmas cactus (Schlumbergera x buckleyi) merits a mention as a hand-me-down plant as it hasn’t been offered in garden centers for half a century. What you’re seeing in bloom at Christmas in garden centers are Thanksgiving cacti (S. truncata) that were specially treated so they would bloom at Christmas. You can learn how to distinguish between the two here.

The true Christmas cactus is not much appreciated in garden centers, as its distinctly hanging stems make it hard to ship (the more upright stems of the Thanksgiving cactus are much easier to manipulate), so it can be hard to find. However, I know lots of people who grow the real thing in their living rooms and have done so in some cases for over 40 years.

Boston Fern

20160120H

The real Boston ivy (Nephrolepis exaltata ‘Bostoniensis’)

Including this plant of the list of hand-me-downs is a bit risky because there are so many look-alike ferns on the market, all cultivars deriving from Nephrolepsis exaltata or other Nephrolepis species. However, today’s modern clones are smaller, more compact plants than the true Boston fern, Nephrolepis exaltata ‘Bostoniensis’. This plant becomes quite a monster, from distinctly arching medium green fronds to over 3 feet (1 m) in length, dripping downward like a cascade. It also produces dozens of thin green hairy rhizomes that dangle below the foliage like so much vegetable spaghetti. The original was introduced in 1894 and was the classic plant for the parlor, that room once found in every middleclass home and used solely for receiving distinguished guests… and funerals. You can still finds huge specimens of this fern in private homes, but also in churches and convents. Traditionally it was always placed on a pedestal, but it also looks great as a hanging plant.

Screw Pine

20160120I

Pandanus veitchii

Another plant seen in botanical gardens and private homes, but never in garden centers is the screw pine. (Pandanus veitchii). It’s actually a Polynesian tree introduced by Veitch Nurseries in England towards the end of the 1800s. Indoors, it forms a rather large plant with arching linear leaves of a waxy appearance, with small sharp hooks at the margin and on the underside of the leaf. The leaves are striped green and white. Over time the plant produces pretty impressive aerial roots and a profusion of babies emerging from its base and poking out through its foliage. I often see this big plant in people’s windows when I take my nightly constitutional.

Mother of Thousands

20160120J

Kalanchoe daigremontiana

This upright succulent plant (Kalanchoe daigremontiana, formerly Bryophytum daigremontianum) bears its name well, as its long, thick triangular leaves are lined in dozens of tiny plantlets… and yes, maybe even thousands! It’s also called Mexican hat plant (even though it is from Madagascar), life plant and alligator plant. The plantlets fall off at the slightest touch and root in neighboring pots. Thus, the plant’s owner always has dozens to offer visitors. Garden centers don’t appreciate its naturally invasive habit (after all, imagine the weeding they’ll need to do as the plantlets start to move into and overtake the other plants in the section!). Although absent from garden centers, it is still commonly grown in many homes. Give this tough-as-nails plant plenty of sun and let it dry between waterings and you’ll find it easy to grow. But you too may come find its weedy habit a bit annoying!

There are several other kalanchoes that produce the same kind of plantlets, but K. daigremontiana is the traditional hand-me-down variety.

Any Others?

Have I missed a few essential hand-me-down houseplants? After all, what is common in one area might not be in another, so that is quite possible. If so, let me know and if I agree with you, I’ll update this blog.

Can’t Find Them?

Yeah, well there’s the rub: by very definition, hand-me-down plants just aren’t commercially available. As mentioned above, ask at your local horticultural society. Also look in flea markets and of course, at plant exchanges. Or visit grandma: she just might have one.

Among the few mail order nurseries that carry some of these plants are Glasshouse Works, Logee’s Greenhouses and Top Tropicals, all in the US. Canadians will need an import permit (from the federal government) and a phytosanitary certificate (supplied by the nursery) in order to import them.