A Spa Treatment for Houseplants

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As houseplants start to come out of their winter lethargy, it’s time to treaet them to a good spa day! Source: www.pflanzenfreude.de

Indoor plants render great services to their owners. They decorate our homes, they purify the air we breathe, they reduce the frequency and duration of colds and flus, and their presence even helps eliminate depression and puts us in better mood (although nobody knows exactly why!). But what do we do in return for them? Very little, except to water them a bit from time to time.

At this time of the year, when the days are beginning to lengthen and our indoor plants are starting to emerge from their winter lethargy, there are a few things we could be doing to make them happier: call it a reward for services rendered!

1. A Cleansing Shower

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Houseplants appreciate an occasional shower as much as you do. Source: Claire Tourigny, Les 1500 trucs du jardinier paresseux

Houseplants absorb much of the dust in the air that surrounds them. It’s is one of the reasons they’re so good for our health. Dust is, in fact, one of their main sources of minerals. However, when dust and dirt start to accumulate on foliage, as tends to happen indoors, it clogs their breathing pores (stomata) and the poor plants start to function less efficiently. Besides, there may be undesirable insects hiding on their leaves that you haven’t yet noticed. That’s why houseplants like nothing better than an occasional warm shower, especially after a long winter.

Yes, a shower, in the shower stall or in the bath using a telephone shower handset. Just cover the surface of the soil with a rag beforehand to prevent the soil from washing away. If you can, rinse both sides of the leaves. If the foliage is really dirty, even take a soapy cloth and gently rub both sides of each leaf. The plants will love it!

2. A Little Leaching

After months of being watered in a closed system (irrigation water drains through the pot into the saucer, then is reabsorbed by the plant rather than draining into the surrounding soil as it would in nature), mineral salts start to accumulate in the soil of our houseplants, over time reaching harmful or even toxic levels. This toxicity is even more severe when we fertilize our plants frequently. To eliminate these excess salts, nothing beats leaching! Set your plant in a shower stall, bathtub, or sink and gently run warm water over the soil, letting excess water flow down the drain. Often the drainage water is tinted yellow, a sign that the soil was quite contaminated. Just soak the sol for a minute, stop for 5 minutes (this will give mineral salts a chance to dissolve), then rinse again until the water that comes out of the pot is clear, indicating that most of the impurities are gone. Finally, let the pot drain thoroughly before putting the plant back in its saucer.

3. A Bit of Grooming

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A bit of grooming – removing dead and yellowing leaves and damaged or dying branches – will benefit most indoor plants. Source:  http://www.mein-mediterraner-garten.de

Over time, most houseplants will accumulate yellowing or brown leaves, dead stems and other defects. Therefore part of the spa treatment should involve a bit of grooming. First, exfoliate… that is, remove dead or yellow leaves. If any leaf tips are brown (often caused by excess minerals in the pot, a problem you just solved through leaching!), you should be aware they will never turn green again, so just clip them off. Depending on the plant, it may be necessary to shorten or remove broken, weak, or overly long branches.  If the plant is heading straight for the ceiling, off with its head! Don’t worry, it will soon grow a new one (that is, as long as it is not a palm: never cut the top off a palm, as they don’t branch in response to pruning!). You can always use the plant’s top as a cutting and start another plant.

4. Time to Repot

After a year or two in the same pot, most houseplants are ripe for repotting. Take the plant out of its pot and remove part of the old soil mix: only a bit if you have been repotting annually, more if the plant has spent more than two years in the same pot. If you want the plant to grow in size, repot into a larger pot. If you want to slow its growth, repot into in a pot of the same size. Before reusing the same pot, clean it thoroughly. You’ll need fresh potting mix, readily available in any garden center. For orchids, buy a potting medium designed specifically for them.

5. A Plant Sauna 

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Many plants do so well once you’ve sealed them inside their plastic “greenhouse” you’ll be reluctant to take them out again! Source: laidbackgardener.blog

If you feel a foliage or flowering plant is in poor shape, a move to a very humid environment will do it a world of good. And creating one is easy. Just find a clear plastic bag and seal the plant inside. Don’t worry that it will suffocate: remember that plants recycle the very air they breathe, absorbing carbon dioxide and producing oxygen during the day and absorbing oxygen and producing carbon dioxide at night. The humidity in the bag will reach a very high level, usually close to 100%… and most houseplants adore high humidity! Leave it in its own personal sauna for two weeks, a month, maybe two months… until you see it showing renewed vigor. During this treatment, place the plant in a bright location, but away from direct sunlight, otherwise the temperature in the bag will become unbearably hot. Note too that plants sealed inside clear plastic bags will probably not need watering, even after several months.

As mentioned, most plants will love this experience… but not cacti and succulents. Unlike other plants, they can’t handle extreme humidity. Never seal them in a closed container for any length of time.

6. Feed Lightly

Most houseplants need no fertilizer in the winter and so you probably stopped feeding them in October or November. Well, March is a good time to start again. Every gardener has his or own preferred fertilizers and fertilization frequency and plants are quite accepting in this regard: notably, any fertilizer is fine with them. You can feed your dracaena or African violet lawn fertilizer for all they care: minerals are minerals and much of the labeling pretending one fertilizer is better for plant X than the other is just hype.

7. A Place in the Sun

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Place your plants in bright light and just watch them explode with new, healthy growth! Source: http://www.obi.de

As you get to the end of your plant’s spa treatment, remember that to remain in good health, your plant will need good light, usually a spot that receives a few hours of sun a day, but without ever becoming stiflingly hot. A location near a east-facing window is ideal because there is reasonable light in all seasons and it never gets hot, so you can leave the plant there all year. South and west exposures are great too, but during the summer, it will likely get too hot near the window and you’ll have to move the plant back a bit. As for a northern exposure… well, it is acceptable (although just barely) in summer, but few plants appreciate it in the winter.

8. Give the Occasional Spin

Finally, to maintain good symmetry, a plant needs to receive light from all sides… which is almost never the case indoors where all the light in a room comes from one direction, because most rooms have windows on only one side. The plant will then tend to lean towards its only source of light. To compensate for this, remember to give it a quarter turn clockwise with every watering. That will give it light from all directions and therefore better symmetry.

Why clockwise? Actually, counterclockwise would work just as well. The important thing is to be consistent and turn it in the same direction each time you water.


And there you go! Plant care equal to that of the best spas! Spa treatment will make your houseplants very happy and yet will cost you practically nothing besides a bag of potting soil and, every now and then, one or two new flower pots. It’s the least you can do for such faithful friends!

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Plants with Weird Leaves: Leaves That Move

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Some leaves really like to shake it up! http://www.oogazone.com & freedesignfile.com

From time to time, I like to write an article about the oddness of some leaves. Here’s yet another, about plants whose leaves actually move.

Leaves Move All the Time

The truth is, leaves that move are not that unusual. They notably move in the wind, or when touched by rain drops or brushed against. However, there are extraneous movements: the plant isn’t moving on its own, it is being moved. That said, many plants do have leaves that move themselves. You’ll learn more about them by reading the following text.

Movement for Protection

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Resurrection fern (Pleopeltis polypodioides) fronds curl up and look dead when dry, but will green up again when the rains come. Source: apalacheehills.com

Many plants have leaves that curl up or roll down under stressful conditions—drought or cold, for example—but recover afterward. The resurrection fern (Pleopeltis polypodioides, syn. Polypodium polypodioides) can survive without a drop of water for many months, even years, then its apparently dead fronds become completely green and functional within 24 hours after a good soaking. Two other resurrection plants are the rose of Jericho (Selaginella lepidophylla) and the alpine gesneriad ramonda (Ramonda spp.).

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These drooping winter rhododendron leaves will straighten up, uncurl and come back to life when warmer weather arrives. Source: http://www.indefenseofplants.com

As for movement to improve cold resistance, the thick leaves of many hardy rhododendrons (Rhododendron spp.) lose most of their moisture and both curl and hang limply all winter, giving their owners quite a scare, yet recover fully when spring returns. It’s thought this habit helps keep frost crystals from forming and damaging leaf cells.

Turning Towards the Sun

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Unless turned regularly, most houseplants will bend in the direction of the light source, Source: Donnie, http://www.houzz.com

On most plants, leaves will turn to face the direction of the sun, at least to some degree. If you transplant or otherwise move a plant—or even if you just cut an overhanging branch that was blocking the sun!—the leaf will adjust, changing its position, usually quite slowly, over days or weeks. This is particularly easy to observe on a forest edge where most light comes from the side or on a windowsill in your home if you don’t give your houseplants the traditional quarter turn regularly: most of the leaves will clearly orient towards the light. This habit of growing towards the source of light is called phototropism. (Remember that term from school?)

Night Moves

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Prayer plant (Maranta leuconeura) leaves move upward at night, like hands in prayer. Source: Aida F., http://www.pinterest.

Other plants have the curious habits of folding their leaves at night, either upward or downward, a phenomenon called nyctinasty. It’s actually very common in some plant families, such as the legume family (Fabaceae) and the oxalis family (Oxalidaceae). You may have noticed this in clover (Trifolium) or false shamrock (Oxalis triangularis), but the best-known nyctinastic plant is the popular houseplant known as the prayer plant (Maranta leuconeura), whose leaves fold up at night like hands in prayer.

This kind of movement is caused by a hinge-like structure at the base of the leaf or leaflet called the pulvinus (plural: pulvini) that is filled with water during the day, but drains at night, so that the resulting lack of turgor causes the leaf to fold.

Scientists still debate why plants do this.

Plants That Dance

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Carefully watch the fire fern (Oxalis hedysaroides ‘Rubra’)—not this photo but a real plant!—and you’ll discover it’s in nearly constant movement. Source: bluepumilio.com

There are plants that, under the appropriate conditions, take the concept of nyctinasty one step further. They too have pulvini and do close at night, but during the day, seem to be constantly readjusting themselves. The fire fern (Oxalis hedysaroides ‘Rubra’), not a fern at all, is a red-leaved oxalis sometimes grown as a houseplant, one of these “dancing plants.”

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The telegraph plant (Codariocalyx motorius) seen using time-lapse photography. You can actually see it move, but not quite that fast! Source: gfycat.com

The telegraph plant (formerly Desmodium gyrans, now Codariocalyx motorius), is another occasional houseplant with seemly motorized leaves.

Both plants will only perform when conditions are fairly warm and humid, but if you sit in from of one and watch patiently, you’ll see each leaf seems to be slowly moving, giving the impression the plant is lazily dancing. The fire fern will also react to touch, at least to a slight degree, but more about touch sensitive plants later.

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The carambola (Averrhoa carambola) has leaves that move all on their own. Source: biogeodb.stri.si.edu

The tropical fruit carambola or starfruit (Averrhoa carambola), in the Oxalidaceae, likewise has leaflets that both close up at night and move visibly, although slowly, during the day, all on their own … if you watch them patiently!

Response to Touch

Plants that react to touch are certainly the weirdest of all plants with leaves that move. This phenomenon, known as thigmonasty or seismonasty, occurs when something touches or shakes the leaf. And some will also react when you hold a match up to them. This can be incredibly rapid and is certainly visible. Again, all these plants close up at night and, again, it’s pulvinus at the leaf or leaflet’s base that empties rapidly, causing the leaf folding. Studies show that there is even an electrical current that runs between the pulvini on many of these plants, almost like nerves in animals, plus there is also a chemical reaction involved.

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Sensitive plant (Mimosa pudica). Source: worldoffloweringplants.com

The best known thigmonastic plant is the sensitive plant (Mimosa pudica), a legume also known as sleepy plant, dormilona, touch-me-not or shy plant, a decent if usually short-lived houseplant easy to grow from seed … and also a pernicious and quite prickly weed in tropical countries. A light touch will cause a single leaflet of the bipinnately compound leaf to fold inward, a firmer touch will lead to the whole leaf drooping and shaking the plant will cause all its leaves to collapse. If you run a finger down the leaf, the leaflets will close like dominoes, as in the photo below. Yet if you leave the leaf alone, it will recover in just 15 to 30 minutes.

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Mimosa pudica leaf closing. Source: Mimosa_Pudica Hrushikesh, Wikimedia Commons

It’s thought this quick reaction to touch helps prevent foraging by grazing animals. I mean, wouldn’t you stop eating if you thought you were biting into a luscious plant, then the leaves all collapsed after your tongue touched the first one, leaving the plant looking barren, unappetizing and full of (previously hidden) thorns?

M. pudica is the most commonly grown sensitive plant, but there are some 400 other species in the genus Mimosa, both herbs and shrubs, all sensitive to touch to at least some degree. There is even a hardy sensitive plant (zone 5) that can be grown as a perennial, M. nuttallii.

Note that these are true mimosas, not the trees and shrubs often called mimosas and which are actually very different, non-sensitive plants with similar pinnate leaves such as Albizia julibrissin (silk tree) and several acacias, including Acacia dealbata (blue wattle or mimosa).

There are also several species of “aquatic sensitive” (Neptunia spp.) with leaves much like those of the sensitive plant that react to touch in a similar fashion. As the common name suggests, they grow in water or at least under very boggy conditions.

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Little tree plant ((Biophytum sensitivum) has leaves that move. Kenraiz, Wikimedia Commons

Less well known is the little tree plant (Biophytum sensitivum), a small herbaceous houseplant in the Oxalidaceae that looks like a tiny palm tree and is sometimes used as a tree substitute in terrariums and fairy gardens. It is modestly touch sensitive … but its leaves move all on their own much of the time, albeit quite slowly.

Finally, the partridge or sensitive pea (Chamaecrista fasciculata), a fairly common annual species of legume native to the eastern United States, also has pinnate leaves that close at night … and are slightly sensitive to the touch during the day.

Touchy Feely Carnivores

The other group that includes plants sensitive to touch are carnivorous plants or, more correctly, insectivorous plants.

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Venus flytrap (Dionaea muscipula) with its leaf traps. To learn how to grow this capricious plant, read No Hamburger for the Venus Flytrap. Source: Citron / CC-BY-SA-3.0, Wikimedia Commons

The best known of these is the Venus flytrap (Dionaea muscipula), often offered as a houseplant, although rarely very long-lived in the average home environment. I already wrote a bit about this plant in 5 Plants with Weird Foliage. It’s bear trap-shaped leaves are dotted with tiny hairs. If an insect touches one hair, nothing will happen. This is believed to be a protection to keep leaves from closing for inopportune reasons, such as when a raindrop or a fallen leaf touches it. However, if the hair is touched a second time within 20 seconds, or if a second hair is touched within the same time limit, the cause is probably a wandering arthropod and the trap closes rapidly, in one tenth of a second. After that, the insect is slowly digested, then the trap opens again. It takes 5 to 14 hours for the trap to reopen after a false alert, while actually digesting an insect can take 10 days or more.

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The trap leaves of bladderworts (Utricularia spp.) do their job underwater, so it’s not easy to see them catch their prey. Source: wetland-plants.co.uk

Less well-known than the Venus flytrap, bladderworts (Utricularia spp.) are even faster. Their bladder-shaped trap is small modified leaf, so designed that when it is “set,” a vacuum forms inside the bladder. If a water flea or other small invertebrate touches the sensitive hair on the outside, the trap opens, instantly sucks in the creature, then closes. The whole process only takes ten to fifteen thousandths of a second.

Gardeners won’t likely find this trap as fascinating as that of the Venus flytrap, as all of this action takes place more or less out of sight underwater or even underground in soggy soil, as bladderworts are bog or aquatic plants.

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Some sundews (here, Drosera capensis) have leaves that will (slowly) wrap around the insects they have caught. Source: Noah Elhardt, Wikimedia Commons

Other insectivorous plants show some leaf movement. Some sundews (Drosera spp.) have leaves that will slowly wrap around their prey once it is glued to the sticky glands that cover them, but this happens so slowly you’d need a time-lapse camera to notice. Butterworts (Pinguicula spp.) leaves also roll up slightly when they trap a prey item, but their movement is even less impressive than that of sundews.


Leaves that move: one of Mother Nature’s little surprises!20180211A www.oogazone.com & freedesignfile.com.jpg

Take Your Houseplants for a Spin

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This jade plant (Crassula ovata) is leaning towards its only source of light.

Indoor plants get their lightly mostly from a sideways direction, whereas outdoor plants catch most of their rays from above. No wonder many houseplants tend to lean sideways — they’re leaning toward the light. A plant that continually leans in one direction eventually winds up flat on its side with its potting mix spread across your carpet. Not a good thing!

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A skylight will let in light from above… but at what price?

One solution to the leaning-plant problem is to install a skylight in your ceiling. Plants that receive light from above are naturally more symmetrical than plants that receive their light from conventional windows. But a skylight will cost you an arm and a leg! And isn’t even possible if you live in a apartment or a condo.20170110B.jpgA cheaper solution is to simply give your plants a quarter turn, always in the same direction, every time you water them. This technique is simple, cheap and effective – and the plant grows evenly in all directions just as effectively as if you had punched a $2,000 hole in the roof!

For attractive indoor plants, therefore, make giving a quarter turn a habit!

Unobtrusive Staking for Houseplants

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The discrete staking on this dieffenbachia is hardly visible at all.

In a perfect indoor gardening world, you wouldn’t need to stake a non-climbing plant. Its branches would be thick and solid, perfectly capable of holding the plant up, even when it’s loaded down with leaves, flowers, and fruit. In reality, though, houseplants are prone to weak growth. Their stems often stretch for the light source, and the abnormally long distance between each leaf node means that they’re less rigid than plants growing outdoors under brighter conditions.

Also, believe it nor not, moving in the wind actually strengthens the stems of plants that grow in the garden. Indoor plants rarely feel any wind at all and consequently, don’t develop stems as strong as they normally would.

Prune Before You Stake

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This staked dieffenbachia would look better if it was pruned back severely.

Pruning and pinching are alternatives to staking. If you prune a plant carefully, removing weak and excessively long stems, the plant likely won’t require staking. When a stem starts to bend over, decide whether the plant wouldn’t be more attractive without that weak branch and, if so, prune it off rather than stake it.

Avoid Fertilizing When Light is Low

It’s best to avoid fertilizing houseplants when the days are short (late October through late February or early March) in the Northern Hemisphere. This tends to stimulate etiolation: long, wispy stems that may well need staking.

The Famous Quarter Turn

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This plant is growing towards the light: it would be more attractive if given a regular quarter turn.

Everyone has heard that you should give a windowsill plant a weekly quarter turn (always in the same direction) so that it will receive light from all directions… but not so many people actually do it. If you carry this out, though, you’ll find your plant much more symmetrical and less in need of staking.

Making Staking Less Visible

OK, so you’ve tried your best and your houseplant does need staking. If so, try to make the stake as unobtrusive as possible because there’s nothing pretty about a plant wearing a splint. Try the following suggestions:

  • Insert stakes near the center of the plant, hidden among the leaves and branches.
  • Always use a stake that will be at least slightly shorter than the plant itself.
  • Consider using the plant itself as a support. You can do this by attaching a weak branch to a stronger neighbor.
  • If you need to stake several branches, use individual stakes for each branch. A web of string and ties wrapped around a single  stake and tied to several branches adds up to one messy eyesore.
  • Avoid brightly colored stakes. Dead branches brought in from the garden, green-tinted bamboo, olive-green plant stakes, and so on, work like camouflage. Or, wrap a colored stake in green florist tape.
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    Green staking tape is fairly discrete.

    Avoid highly visible fasteners. Green twist ties, green or natural-colored raffia, garden twine, and soft plastic plant ties in off-green shades make good choices.

  • Try to re-create the plant’s natural growth pattern when you attach the branches to stakes. Avoid bunching stems together or cramming flower heads up against each other.
  • Surround weak-stemmed plants with solid neighbors. If they can lean just a bit, they’ll likely stay standing.

20161106H.jpegThe information in this blog was largely derived from one of my books, Houseplants for Dummies. This is only one of several books on houseplants I have written over the years. I encourage you to read one.20161106c