Some succulent plants and their friends do not mind being grown as houseplants. Ponytail palm, Beaucarnea recurvata, is one of those rare friends of succulents that actually prefers to be inside, at least during winter when they can be damaged by cool weather and moisture. Plants that are houseplants through winter and get moved out to the garden through summer should be protected from harsh direct exposure since their foliage is adapted to the home environment. Otherwise, ponytail palm likes the sunniest rooms in the house.
The weird distended caudex at the base of the stem is the most distinctive feature of the ponytail palm, which as actually neither a palm, nor outfitted with ponytails. However, almost like a palm, pruning a solitary top down will likely be fatal. (Pruning the terminal bud off the top of a palm will necessarily be fatal to the affected trunk.) Unlike (solitary) palms, ponytail palm can eventually develop multiple trunks, which can be pruned off if absolutely necessary.
In their natural environment, ponytail palms can get to be shade trees with sparse limbs terminating with tufts of narrow strap shaped leaves. Yet, as slowly growing houseplants confined to containers, they rarely get more than six feet tall after many years. They really need good drainage, and prefer to be watered only about twice to four times monthly.
What a weird tree! Fiddle leaf fig, Ficus lyrata, is an uncommon but familiar large scale houseplant that we might not welcome into our homes if we knew how it behaves where it grows wild in the lower rainforests of Western Africa. Although it can grow upward from the ground like almost all other trees do, it often germinates and begins to grow as an epiphyte, within organic debris that accumulates in the branch unions of other trees. While suspended, it extends roots downward. Once these roots reach the forest floor, they develop into multiple trunks that overwhelm and crush the host tree as they grow.
The bold foliage is typically dark drab green, like the shades of green that were so popular for Buicks in 1970, with prominent pale green veins. Individual leaves are about a foot long and potentially nearly as broad at the distal (outward) ends, often with randomly wavy margins. Like fiddles, they are narrower in the middles, or actually more often narrower at the proximal (inward) ends. When pruning becomes necessary, the caustic sap should be soaked from fresh cuts with paper towels so that it does not drip and stain.
It is difficult to see how string of pearls, Senecio rowleyanus, is related to much more colorful daisies and asters. The small, fuzzy and sickly white flowers are not much to look at, and only clutter the elegantly pendulous and oddly succulent foliage. The round leaves are light bluish green, so actually resemble peas more than they resemble pearls. The stems are so very thin and limber that they can only stand a few inches high, but can cascade to three feet!
Although evergreen, stems of outdoor plants can be cut back while dormant through winter to promote fresher growth in spring. The pruning scraps are very easy to propagate as cuttings. Roots are undemanding and sensitive to rot, so should be allowed to get nearly dry between watering. Bright ambient light without too much direct sun exposure is best. Incidentally, all parts of Senecio rowleyanus are toxic.
Chrysanthemums, hydrangeas, azaleas, callas, kalanchoes and miniature roses can not really be as happy as they seem to be while in full bloom at the florist counter. Then there are all the seasonal blooming plants like Easter lilies and poinsettias. Wrapped in undraining mylar, often with ribbons and bows, they are actually quite humiliated.
All are forced to bloom in artificial greenhouse environments that are nothing like the home environments that they ultimately go to. As they finish bloom, most get retired directly to the garden where many are unable to adapt quickly and efficiently enough to survive for long. Many do not make it that far, but get sent to the compost or the trash by those who prefer to not prolong their agony.
These potted plants (which are actually known as ‘pot plants’ in the horticultural industries) are not like houseplants, since they are not actually expected to survive for long in the home. They are only expected to perform for a limited time while in bloom.
Adapting to the home environment is not the difficult part. Most potted plants can manage that for a while, but eventually want more sunlight. Hydrangeas, roses, Easter lilies and other deciduous plants also eventually want a cool winter for their dormancy. The problem is adapting to exposure to the sunlight and weather that these plants crave. Foliage can get scorched, frozen or desiccated.
As unsightly as plants can be during transition, most can eventually replace their greenhouse foliage with foliage that is adapted to their new environment in the garden if transitioned slowly and carefully. Large ‘forced’ flowers will eventually be shed or can be pruned off as they deteriorate. The more sensitive types of plants should be moved to a sheltered spot on a porch or in partial shade for a few months before being moved to more exposed spots. Once in the garden, they will want regular watering until their roots disperse.
Deciduous plants and bulbs can stay in the sheltered spot until they defoliate for winter. If put into their permanent location while dormant and bare, their new foliage that emerges in spring will be adapted to the new exposure.
Aloes, Christmas cactus and various other succulents are considerably more resilient and adaptable than the more common potted plants. Both rosemary and small olive trees that have become trendy during the past many years can likewise be adaptable if not kept in the home too long. Olive trees can stay potted indefinitely if pruned regularly, or can go into the garden where there is room to grow. Christmas trees are just as adaptable, but do not want to stay potted for long. Sadly though, most get much too big for home gardens.
Pruning a rubber tree, Ficus elastica, in the home takes a bit of acrobatics, since any wound immediately bleeds staining white latex. While pruning with one hand, the other hand must catch the latex with a rag. A third hand is needed to catch the bleeding piece of stem that gets pruned away. To make things more complicated, all three hands should avoid the potentially caustic latex. Even if it is harmless to the skin, it is a painful irritant if it gets into the eyes.
Young trees have larger glossy leaves that may be as long as a foot and half as broad, although most are about half as long and broad. Many modern cultivars have variegated or bronzy foliage. Where it gets enough sunlight as a houseplant, rubber tree will eventually need to be pruned for confinement. After all, in the wild, it can get more than a hundred feet tall and almost two hundred feet tall, with trunks more than six feet wide! In the garden, it needs shelter from frost. Aerial roots can develop in humid environments.
Most of the favorite houseplants are grown for dense evergreen foliage. Stems of Chinese evergreen, anthuriums, bromeliads and most ferns should never be seen. Yet, there are many houseplants that grow like small trees or coarse vines. Various ficus, dracaenas and philodendrons can get too big for their situations if not pruned. Palms can not be pruned down, so can only be moved or given to friends with higher ceilings.
Pruning and discarding overgrown but slowly growing stems seems like such a waste. Technically, stems from almost any overgrown houseplant can be rooted as cuttings. In reality though, most rot before they develop roots.
‘Air layering’ is probably the most efficient technique of propagation of houseplants from overgrown stems. It involves rooting the stems while still attached to the original plant. In the end, an unwanted stem gets pruned away as a freshly rooted new plant.
Air layering needs a bare and manageable section of stem that is at least a few inches long. This section does not necessarily need to be where the stem will eventually get pruned away from. It can be a bit higher (or farther out from the origin) if a shorter copy (new rooted plant) is desired. The extra length of stem in between can be pruned out when the copy gets separated.
The stem should be notched up to a third of the way through. This notch will develop roots better if rubbed with rooting hormone. A big wad of wrung out damp sphagnum moss a bit larger than a softball then gets wrapped around the notch, and then wrapped in plastic film. A cut up freezer bag should work nicely. The bag should be held in place with plant tie tape or something as simple as electrical tape, wrapped firmly around the stem above and below the sphagnum moss. Smaller stems can get smaller wads of sphagnum moss.
Unfortunately, there is no way to disguise the unappealing wrapped moss during the few months that may be needed for roots to develop. Eventually, roots become visible through the plastic, or the moss becomes firm with roots. The newly rooted stem can then be cut below the roots, unwrapped and potted as a new copy of the old houseplant. The stub below can be pruned away, or left to develop new shoots.
The tiny, yellow buds at the center of poinsettia (Euphorbia pulcherrima) blooms are actually the unimpressive flowers. The colorful red, white, pink or rarely pale orange bracts surrounding these flowers are merely colorful leaves. Some varieties have marbled, blotched or spotted bracts. Compact potted plants that are mostly less than two feet tall and broad can get quite lanky and taller than ten feet in the garden. The dark green leaves are about three to five inches long.
It is no coincidence that Chinese evergreen, Aglaonema, is perhaps the most common tropical plant for interiorscapes. It is quite easy to care for, and available in so many unique personalities. Many have rich deep green foliage. Most are elegantly variegated with white, silvery gray or gold. Leaf shape is quite variable, although most have rather narrow leaves radiating outward from dense rosettes. Leaves can be half a foot to more than a foot long, and a bit more than an inch to almost six inches wide. Mature plants are at least a foot tall and a foot and a half broad.
Indirect sun exposure or partial shade is best. Chinese evergreen likes humidity, so likes to share sheltered enclosed atriums with other lush foliage plants. New plants are easy to propagate by division.
Hibiscus, bougainvilleas, philodendrons and so many of the tropical and subtropical plants that we can enjoy in our gardens can only survive through winter in greenhouses in most other climates in America. Many of our tropical houseplants though, seem to be the same everywhere. Houseplants are generally grown in our homes not because they can not survive in our gardens, but because they ‘can’ survive in our homes.
Yes, houseplants are merely any plants, tropical or otherwise, that we grow in our houses. Yet, most and perhaps almost all of the plants that are best adapted to surviving as houseplants happen to be tropical plants. Tropicals do not need the seasons that they would get outside. Because many are native to dense and very competitive tropical forest environments, they are adapted to the sort of shade that they get in our homes, and survive on minimal volumes of soil that they have available while potted.
Nonetheless, they miss their tropical lifestyles. They only tolerate dry interior air, but would prefer more humidity. They would likewise prefer to be rinsed of dust more often than they can be in indoors. A regular supply of fresh organic debris to supply nutrients would be nice. However, if merely fertilized instead, tropicals are sensitive to salts and other toxins that eventually accumulate in the soil.
This is why some of the more resilient houseplants like to be brought outside for a gentle rinsing during a mild rain. As long as it is not too cool or windy, gentle rain rinses dust from the foliage and toxins from the soil. Plants can be brought out in the morning and brought in late to get as much time out in the rain as possible, but should not be left out overnight when it may get too cool. Even though they do not need any more moisture, plants can be watered by hose a few times to allow water to rinse freely through the soil.
Plants in overly decomposed potting soil are easier to repot with fresh soil while they are outside. Those that do not need to be repotted might still like getting grungy and potentially toxic mineral deposits scrubbed from their pots and drainage pans.
Back when big spider plants or Boston ferns suspended in fancy beaded macrame were all the rage through the 1970’s, burrow’s tail, Sedum morganianum, was an unusual but also trendy succulent perennial for sunny spots in the home or sheltered and slightly shaded spots in the garden. The refined foliar texture and light bluish green color contrasted nicely with the big and deep green leaves of comparably trendy philodendrons. The thin stems are too limber to stand up, but cascade excellently. Plants in the garden that get pruned back while dormant in winter can easily get two feet long through summer. Without pruning, big plants can get longer than six feet. Pruning scraps and even the small but plump leaves can be rooted and grown into new plants. It is impossible to prune or even move burro’s tail without dislodging some of the leaves anyway. Watering should be regular but not excessive, but then minimal for plants in the garden through winter.