Coleus

No flowers needed with this foliage!

Out in the garden, coleus, Plectranthus scutellarioides, prefers partial shade where the foliage is less likely to get roasted during arid and warm summer weather. It is grown as a warm season annual instead of as a perennial, because it gets so tired through winter, and can be killed by even a very mild frost. Its sensitivity to exposure in the garden is probably why it is more familiar as a houseplant.

The flashy and sometimes deeply lobed foliage is variegated with any combination of green, chartreuse, yellow, orange, red, burgundy, pink, white, brown and almost black. Flower spikes should be snipped as they develop to keep foliage dense. The tiny purple flowers are not much to brag about anyway. Large plants can get to two feet tall and broad. Cuttings root easily in rich and regularly moist potting soil or just plain water. Seeds need sunlight to germinate, so should only be pressed onto the surface of damp potting soil without getting covered, and misted daily.

Houseplants Bring The Outdoors In

Many houseplants will not live outside.

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.

Rabbit Foot Fern

 

Rabbit foot fern has lacy leaves.

Rabbit foot fern, Davallia fejeensis, is one of those few plants that actually seems to be happier in pots, particularly unglazed terracotta pots that stay damp where its oddly fuzzy rhizomes creep over the edges. Besides, pots have the advantage of portability, so that appealing plants can be brought into the home as houseplants, even if only for a few months at a time. Rabbit foot ferns that lose leaves because the air in the home is too dry should recover if moved to a shady and humid spot out in the garden for a while.

The fuzzy rhizomes are as appealing as the foliage, and can creep a foot or even more if they wrap around a pot. They rot if buried, so should be spread out over the surface of the potting soil when small plants get put into larger pots. The very lacy foliage can get a foot deep in damp and partly shady spots. Foliage is shorter and more dense with more sunlight.

Elephant Ears

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The origin of taro is vague.

Taro was grown as a vegetable in ancient Egypt. It was grown in India before that. A few hundred varieties were cultivated in precolonial Hawaii. Taro was likely native to southeast Asia, but has been in cultivation for so long that it is difficult to know where it originated from. In modern American gardens, it is known as elephant ears, Calocasia esculenta, and grown for its striking foliage.

The big and broad leaves are held as high as six feet on long petioles (leaf stalks), and flare out as broadly as three feet, although many varieties get half as tall and broad. Some varieties have weirdly dark foliage. Others have green leaves with colorful veins. A few are simply jade green. Any of the deciduous foliage that lingers into winter should be cut back before spring.

Since they are naturally bog plants, elephant ears likes very rich potting soil and plenty of water. Muddy clay soil that will not float away works fine for pots submerged in ponds. (Ick!) Partial shade is important. Leaves can get roasted if too exposed. To propagate, corms can be divided while dormant in winter. All parts of elephant ears are toxic until cooked.

Boston Fern

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This fern is nowhere near Boston.

It is not actually from Boston. The first Boston fern, Nephrolepis exaltata ‘Bostoniensis’ was merely discovered in Boston, as a mutant in a shipment of otherwise normal ferns. Unlike the more upright parent plants, Boston fern has softly arching fronds that can hang vertically at the ends.

The fronds are typically about a foot and a half long, and can be a few feet long in humid and partly shady environments. Each frond is comprised of many pinnae that are neatly arranged on both sides of a wiry rachis (leaf stalk). Each leaflet is an inch or two long or longer. Delicate aerial roots sometimes dangle below the foliage.

Through the 1970’s, Boston fern was one of the most popular houseplants. Yet, it really prefers more humidity than it gets inside. It is actually happier on porches or in atriums where it is sheltered from frost and harsh sun exposure. It prefers partial shade outside, but likes abundant ambient sunlight as a houseplant.

Ferns Are Made For Shade

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Ferns are famous for distinctive foliage.

Without color or fragrance of flowers, ferns provide some of the most distinctive foliage in the garden. They do not turn color in autumn. Only a few tree ferns develop sculptural branch structure. Yet, they do their job well, and many are happy to do so in spots that are a bit too shady for other plants.

Almost all ferns are low perennials that produce foliage that arches outward from the center. Some can get quite broad. A few tree ferns grow upward on trunks (although the trunks are merely tough roots that grow through decomposing stems). Australian tree ferns can get quite tall and broad where sheltered from wind.

The staghorn fern is a weird epiphyte that naturally clings to tree trunks or rock outcroppings where it collects organic debris that falls from trees above. In home gardens, it is popularly grown on wooden plaques or as a hanging plant. Hanging plants do not necessarily need pots, or sometimes engulf their pots as they grow.

Leaves of ferns are known as ‘fronds’, and with few exceptions, are intricately lobed or divided into smaller leaflets known as ‘pinnae’, which are arranged on opposite sides of leafstalks known as ‘rachi’ (or singularly as ‘rachis’). The staghorn fern has unusually branched but otherwise unlobed fronds. The bird’s next fern has has distinctively simple fronds without any lobes or pinnae.

Most of the popular ferns are naturally understory plants that grow below larger plants. Even most tree ferns grow amongst larger trees. This is why so many ferns tolerate shade so well. In fact, many prefer partial shade, and will actually fade or scorch if too exposed. However, it is also why so many ferns prefer rich soil with an abundance of organic matter.

Maidenhair, rabbit’s foot, bird’s nest, holly, Boston and a few other ferns are popular as houseplants. Because home interiors are a somewhat arid for them (lacking humidity), some ferns like to be misted daily. Ferns respond well to regular but light application of fertilizer. Too much fertilizer can roast foliage.

Because ferns are not expected to bloom, nitrogen (which can inhibit bloom for some plants) is not a problem. Ferns that are out in the garden can therefore get fish emulsion or a bit of the same sort of nitrogen fertilizers that keep lawns green.

Herbaceous Trees

P91005KPalms are like ‘Red Delicious’ apples. It seems that most people dislike them; but they also seem to be very popular. Seriously, if only a few people like ‘Red Delicious’ apples, why are they so common in supermarkets? If most of us dislike palms, why are they so common in the San Jose Skyline?

I suspect that palms really are as unpopular as they seem to be, but that they are also very conspicuous within their situations. Not only are they focal points of the landscapes in which they live, but most types eventually stand as tall as the tallest trees in the neighborhood, and some get significantly taller. They are innately the most prominent trees within their neighborhoods.

Palm are not like other trees though. Arborists may classify them as ‘herbaceous trees’. They are foliar plants while young, producing increasingly large leaves from terrestrial rosettes. They only ‘launch’ and start to develop their trunks after the formerly terrestrial rosettes have grown wide enough to do so.

Not only are their trunks no wider than their associated foliar rosettes, but they get no wider as they grow taller. The base of a trunk of a palm is as wide when the tree is only a few feet tall as it will be when the tree grows to forty feet tall. Mexican fan palms are only wider at their bases because they start out like that.

Palms with slender trunks can launch much sooner than those with wider trunks. It does not take long for their rosettes to get as wide as their trunks. Canary Island date palms have rather plump trunks, so may need to mature for many years before they launch.

Yuccas and dracaenas are not really palms. Their trunks expand and develop branches as they grow and mature.

Candy Corn Dog

P90721Just a short distance from the corn dog orchard, I found this candy corn dog growing wild. I really had no idea that candy corn grew in a corn dog form like this. These particular candy corn seem to have turned from green to yellow to orange as they ripened. It will be interesting to see if the outer ends eventually ripen to yellow like conventional candy corn, or if they are a fancier cultivar. They sort of look like tiny persimmons.

Perhaps it is ‘Cupid Corn’, which is red at the outer end and pink in the middle, for Saint Valentine’s Day. If so, it will be quite stale long before next February.

Even if it is ‘Reindeer Corn’, which is red at the outer end and green in the middle, for Christmas, it will not likely be fresh by late December.

Heck, just expecting it to last until Halloween is a stretch. There are actually a few different cultivars for a variety of holidays, so this one could be for any of the obscure holidays before Halloween that few know about; or it could be very out of season.

I do not know how this candy corn dog got here. I did not plant it. I am pleased that snails, slugs, squirrels or insects have not eaten it so far.

Something came into this part of the landscape earlier, and ate all the foliage off of the Arum italicum. Even though it is a naturalized exotic weed, the Arum italicum was rather appealing, with its intricately lacy foliar variegation. It is completely gone now, but should regenerate once rain resumes in autumn or winter.

For now, the candy corn dog is more colorful than the Arum italicum was. How odd that it has no foliage. hmmmm . . .

Ferns Are Shady But Cool

P90309+++++It could be either an asset or a liability. With few exceptions, ferns do not want to be too exposed to direct sunlight or wind, especially during warm and dry weather. However, as long as they get just enough filtered light, they can be quite happy in sheltered spots that are a bit too shady for other plants. Most like to be watered regularly, and perhaps lightly fertilized in spring and summer.

They provide neither floral color nor fragrance. They lack interesting branch structure and bark. Since they reproduce by spores, they do not even produce any fruit, either edible or ornamental. For those who do not know them any better, they might seem to be rather boring. Yet, those of us who grow them know how handsome their lush, finely textured and uniquely patterned foliage is.

Of the popularly grown ferns, only two develop ‘trunks’, (which are actually just clustered wiry roots growing downward through rotting stems). Two others are ‘epiphytes’ that naturally cling to trees or exposed stone, but in home gardens, are more popularly grown on wooden plaques. Most other ferns are terrestrial understory perennials that naturally live in the partial shade of larger plants.

Although mostly confined to the ground, some ferns can get quite large. Individual leaves, which are known as ‘fronds’, can get several feet long. Even before it develops a trunk, Australian tree fern produces huge fronds that can shade an atrium. Other ferns with smaller leaves can spread very efficiently, and can even become invasive. Fortunately, most ferns are relatively complaisant.

The two popular epiphytic stag-horn ferns have weirdly lobed but otherwise undivided fronds. Leaves of the odd bird’s-nest fern is neither divided nor lobed. Otherwise, fern fronds are intricately divided into small leaflets known as ‘pinnae’. These pinnae are neatly arranged on opposite sides of leafstalks known as ‘rachi’. Some ferns have silvery variegation, but most are rich dark green.

Ferns innately do well in pots. Boston, maidenhair, rabbit’s foot, holly and bird’s-nest ferns are actually excellent houseplants. However, Australian tree fern and a few others shed irritating fuzz that would be a problem in the home. Most of the popular ferns are evergreen. Many consume their own deteriorating foliage by covering it with new foliage. Some ferns need occasional grooming.

Leopard Plant

90410As an understory species that naturally grows under forest trees in its native environment in Japan, leopard plant, Farfugium japonicum, can be quite happy in parts of the garden that are too shady for other plants. If it does not get too warm or dry, it can tolerate full sun. It likes rich soil and frequent watering. Fertilizer should be applied moderately, since too much can cause foliar burn.

Cultivars of leopard plant that are variegated with yellow or white spots, blotches, margins or outwardly and irregularly flaring streaks are increasingly popular, although the unvariegated rich dark green cultivars are still the most popular. Individual leaves get about three to six inches wide. Some are wavy or impressively crinkly around the edges, or outfitted with a few bluntly angular teeth.

The mostly unseen rubbery petioles can suspend the glossy evergreen foliage as high as two feet, although most cultivars stay lower. Rhizomes spread slowly. It may take many years before the healthiest of specimens gets big enough to divide. Leopard plant is grown as a foliar plant, but provides a delightful surprise of loose trusses of inch wide yellow daisy flowers in autumn or winter.