The mostly white and blue common passion flower likely remains the most popular. After all, it is the weirdest. Elaborate and disproportionate floral parts imply that it is of another planet. Red passion flower, Passiflora racemosa, although less peculiar, is perhaps a bit more colorful. Its brick red flowers bloom randomly for as long as weather remains warm.
Flowers are about three or four inches wide. They develop in open racemes that seem to spread out somewhat evenly over the exterior of their foliage. Bloom is not profuse, but is somewhat continuous until autumn. Newer flowers replace older flowers within the same racemes. Leaves are as wide as their flowers, with three blunt lobes and axillary tendrils.
The lushly evergreen foliage can get shabby through winter, or completely ruined by just mild frost. It regenerates vigorously though. Aggressive pruning as winter finishes delays bloom, but promotes vigorous growth. Vines can potentially reach more than twenty feet. Fruit is rare without manual pollination. Fruit flavor can be bland without tropical warmth.
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.
This weird tropical cactus gets mixed reviews. Pitahaya fruit, or dragon fruit, is abundant in favorable conditions, but develops potentially bland flavor. The green succulent stems may be vigorous, but develop distinctly pendulous form that resembles Sigmund the sea monster. Bloom lasts from summer to autumn, but individual flowers open for just a night.
Selenicereus undatas is the most popular pitahaya. Its fruit weighs between half a pound and a pound, and has white flesh. Selenicereus costaricensis fruit is similar, but with red flesh, and perhaps slightly more flavor. Selenicereus megalanthus fruit is smaller, thorny and yellow, with white flesh and richer flavor. Home grown fruit is superior to market fruit.
Pitahaya grows very easily from cuttings or pruning scraps. Young stems climb with wiry aerial roots, so need substantial support. Fruiting stems hang downward from the tops of such support. Most modern cultivars need no pollinator. Some old cultivars need another of its same species for pollination. Pitahaya is vulnerable to frost where winters are cool.
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.
This humongous six inch wide tropical hibiscus, Hibiscus rosa-sinensis, looks like it might be from Hawaii or Florida, but was actually found in K and K Nursery and Landscape of Norman, just south of Oklahoma City, where winter nights are already seriously cold by our coastal California standards. It is happy to bloom so impressively only because it is in a greenhouse. Even here in our pleasantly mild climates, tropical hibiscus are happiest where sheltered above from frost, by eaves or evergreen shade trees that are high enough to also allow warming sunlight through. In the cooler spots, even sheltered plants occasionally get damaged by frost, and need some time to regenerate after winter.
Some of the classic tropical hibiscus that typically have smaller flowers can grow above single story eaves if not pruned down. Most modern varieties with larger or ruffly double flowers rarely reach the eaves, and many stay less than six feet tall even without pruning. The evergreen foliage has an appealing glossy sheen, which is an ideal backdrop for the red, pink, white, yellow or orange flowers.
There are all sorts of philodendrons with all sorts of fancy names. Yet, the biggest and boldest lacks a common name (at least one that is actually ‘common’), and is most popularly known by a Latin name that is not even correct. The proper name for Philodendron selloum is really Philodendron bipinnatifidum. It is a big awkward plant with big and deeply lobed leaves on long petioles (leaf stalks), and weirdly thick aerial roots. Well exposed plants can stand on wobbly trunks. Partly shaded plants can creep along the ground, and prefer to grab onto and climb tree trunks, fences or anything that they can get a hold of. The aerial roots are harmless to trees, and generally too slow to catch a healthy cat, but will take paint off of walls. All parts of Philodendron selloum are toxic.
There is someplace in the world for the brethren of each and every houseplant to grow wild. All houseplants do not originate from the same regions, and many were bred in cultivation, but all originate from somewhere. They are houseplants only because they are plants that can live in a house.
Most houseplants are from tropical regions, and many are understory plants that grow in the partial shade of taller trees. They are naturally tolerant of the mild temperatures and partial shade within the home. Not many deciduous plants will be happy without a winter chill.
Confinement is also a concern, since houseplants need to be potted, and stay below ceilings. Plants that need to disperse their roots will not work. Neither will plants that can not be pruned down as they grow. Some palms that work well in malls have leaves that get longer than the distance between the floor and ceiling in the home!
Most houseplants are grown for foliage instead of flowers, not only because a lack of seasons inhibits bloom, but also because their foliage is naturally so appealing. African violets are one of the more notable exceptions. Amaryllis is all flower with almost no foliage, but typically gets discarded when done blooming.
Coleus and caladiums have such colorful foliage that there is no need for flowers. Bloom actually compromises their foliar quality anyway, which is why flower spikes get snipped from coleus. Mauna loa lily is grown for excellent rich green foliage, but sometimes adds clear white blooms as a bonus.
All sorts of ferns are very good houseplants. However, a few, including the popular Australian tree fern, produce coarse fuzz that can be irritating to the skin. A few others, like sword fern, produce messy spores that can permanently stain fabric and carpet. Just because they can live in the home does not mean that they should.
The various ficus are excellent houseplants because they can grow quite large, but can also be pruned to fit into their particular situations. The popular weeping fig (Ficus benjamina) has an abundance of small glossy leaves. Rubber tree and fiddle leaf fig have big thick leaves. Creeping fig is even more distinct from the others, as a wiry vine that is popularly grown in hanging pots.
The simple pink or sometimes red or white flowers of angel wing begonia are not as flashy as those of other begonias, and are not abundant enough to provide much color. During warm weather, they are merely a minor bonus to the striking foliage. As the name implies, the big and angularly lobed leaves are shaped like wings of angels. Upper surfaces are glossy and dark green with irregular silvery spots. Undersides are even glossier and reddish bronze. With support, the lanky cane stems can get more than twelve feet tall. However, because older tall canes produce runty foliage, they are often pruned out to promote more vigorous and lushly foliated young canes.
Because they are sensitive to frost, and also because they are ideal houseplants, angel wing begonias are typically grown in containers. They like rather regular but not excessive watering, and rich potting soil. Abundant sunlight enhances foliar color; but harsh exposure roasts foliage. Partial shade is not a problem.
Cymbidium orchids have been popular here for as long as I can remember. Back when horticultural commodities were still more commonly grown around the San Francisco Bay area, many genera of orchids, particularly Cymbidium, were grown in acres of greenhouses in the hills of South San Francisco. They are still grown near the coast of San Mateo and Santa Cruz Counties.
In home gardens, they are often pampered under the shelter of lath, where they are protected from frost and direct exposure to sunlight. Some Cymbidium orchids live and bloom for many years or decades, and sometimes get divided into more as they get overgrown, just like lily-of-the-Nile. Some live longer than those who originally grew them, and go live with someone else.
I never pampered my Cymbidium orchids. I grew all of them out in the garden, with only a bit of partial shade from larger trees. I never once potted any of them into the coarse fir bark that Cymbidium orchids supposedly need. I grew most in dirty and uncomposted oak leaves. I put some in rotting stumps to accelerate the rot. They were happy, and bloomed remarkably well.
None of mine were purchased. They were all acquired from neighbors, clients or colleagues. Of the many Cymbidium orchids that I have grown, none were white! Yes, I wanted a white one. I just do not admit to it.
After maintaining it for more than a decade, and bringing it from a former home hundreds of miles away, a colleague brought me this Cymbidium orchid. Although I did not want him to pass it along after so many years, I was pleased to take it, particularly since it blooms white. Then, it started to bloom, immediately after arrival! Ah, if only there were more people here to see it!