POLYSCIAS

A new generation of indoor-plant enthusiasts can enjoy these Asian natives, thanks to the few nurseries now producing high-quality stock.  

By George A. Elbert 
 

The eclipse was not due to any deficiency in the plants themselves, but reflected the reckless way they were being grown in the trade, which resulted in poor quality. The revival has much to do with the esteem with which the plants have continued to be held by both amateur and professional indoor gardeners, as well as with renewed efforts to bring good-quality specimens to the market. 

There are about six species of the Ming aralia's genus, Polyscias, that are actively cultivated. The genus is tropical, with some 80 species from the Pacific islands and Southeast Asia. In warm climates they are grown outdoors; magnificent cultivated specimens are found on Caribbean islands. The family to which the Ming aralia belongs -- Araliaceae, the aralia, or ginseng, family --includes a number of popular house plants, such as English ivy, as well as the herb ginseng. (The polyscias were once included in the related genus Aralia.) 

Polyscias are especially interesting for their foliage -- indeed, the name polyscias means many-shaded, a reference to the luxuriant foliage. Their stalks carry compound leaves with up to seven (or more) opposite leaflets. In several species the leaves are deeply lobed. The leaves are also highly variable, sometimes on the same plant, and frequently variegated. 

The Ming aralia, Polyscias fruticosa, is especially beautiful (see photo at top). Unlike plants that branch sideways, it grows vertically. It is greatly improved by trimming and training: The tips are trimmed in order to encourage more rapid branching and thicken the trunk. The joints, closely set, then produce a thick growth of branches and a dense covering of leaves. The stems zigzag, forming a complex candelabra. With age the lower branches die off, leaving a beautiful, ashen tan, corky surface that is gnarled or bumpy where the branches had been. The complex leaves and unusual stems make a Ming aralia a very oriental-looking plant indeed. The closely related Plumata Ming aralia shown at right is a feathery form with small leaves and is excellent for Bonsai. 

The Ming aralia can be kept small through trimming or can be grown to several feet. One cultivar, the parsley aralia (so-called because its leaves resemble those of the herb) can be grown in a small bonsai pot and will not exceed twelve inches in ten years; exposing the roots further enhances the illusion of bonsai-like miniaturization. In contrast, the species is magnificent as a flame-like mass of greenery eight feet high. It can be used in almost any decorative situation, whether calling for sculptural or architectural treatment. The plant is easy to maintain and propagate. It grows in full sun or heavy shade -- it is quite happy in a north window. Almost any soil will do. And it is easy to make rooted cuttings. 

The polyscias are such excellent house plants that others hardly compare. Why then did they suddenly drop from favor after years of popularity? The answer has to do with the way plants of this genus, like some other house plants, have been prepared for market. House plants can vary greatly, depending on their source. Their differences are partly due to parentage, but even more to methods of culture. 

In the process by which an exotic species is brought into commerce, initial improvements in breeding and culture make it popular with a broad segment of the indoor grower and landscaper market. At first only one or a few nurseries produce the successful plant. But soon others see an opportunity to share in the profits. In order to gain a share of the market, however, nurserymen must reduce the price; and to do that they must find ways to grow the plant at lower cost. That is most frequently accomplished by speeding growth. 

The plants are exposed to high light intensities, provided with higher humidity and gorged on fertilizers containing additives such as sugar products. Given enough time, growers are able to select and propagate clones that grow abnormally fast, thus further reducing the time required to bring plants to market. It takes only a small number of short-cut producers to create havoc in the market. Soon interior landscapers and amateurs alike start to complain about plants that fail. In the case of polyscias, the complaint was about shattering, a term used to characterize a sudden and complete loss of leaves. Properly treated plants do not shatter. But forced plants suffer extreme shock when moved from near-full sunlight conditions to indoor 60 to 90 percent shade. The sudden reduction in fertilization also strips them of leaves. In addition, plants weakened by forcing have fewer roots in relation to foliage and are prone to disease. Most people lack the means to acclimatize forced specimens, so that the plants can overcome the trauma of transition from one extreme environment to another. 

It does not take long before shops notice that badly grown plants are not selling at any price. Buying comes to a halt and within two or three years even active amateur indoor gardeners tend to forget about the plant. Once that has happened it becomes possible to start again from scratch and reintroduce well-grown plants -- but then the job is to re-educate a plant-shy public. Experts are fully aware of the trade induced problem of poor-quality stock, and it is a subject of conversation in the trade but is rarely publicized. What happened to polyscias has also befallen a number of important house plants such as cluster palms and large-leaved ficus. 

Fortunately, polyscias varieties are now making a comeback, with the assistance of a remarkable nursery woman, Lynn McKamey of Rhapis Gardens in Gregory, Texas, a major grower of lady palms (dwarf Rhapis excelsa). She has come to the defense of species and cultivars of the genus Polyscias by collecting superior clones wherever she could find them, and growing them carefully. Her Ming aralias are grown in 80 percent shade -- a level far below normal nursery practice but the right way to prepare polyscias for life indoors. The soil mix is specially prepared and fertilizer is used sparingly. Plants are being selected for improved growth habit, color and adaptability. Hence they do not shatter unless subjected to really bad treatment and generally make a smooth transition to the home environment. Rhapis Gardens is now supplying plants to other nurseries and mail-order customers. Because the Ming aralia has been in short supply, the trade has had no choice but to turn to it. 

Worthy Polyscias for display:  

A variety of other polyscias cultivars, both old and new varieties, will greatly enhance the house plant repertory. Unfortunately, species names in the genus have been undergoing changes. The changes are needed in order to follow the standard botanical rules of nomenclature of species; nevertheless, the new names are likely to be recognized by neither florists nor the public. Buyers should be on the alert for either name. 

Polyscias balfouriana should, in the opinion of some experts, be called P. pinnata. Also known in the trade as the dinnerplate aralia, it has roundish one-and-a-half or two-inch leaves that are deeply notched at the base, some-what cupped and having an edge corn-combining scallops with small sawteeth. Cultivar 'Marginata', often called Geranium-leaf, is the same, except that the leaf edges are irregularly marked with white. 

Cultivar 'Pennockii' is justly famous for its three- to four-inch oval leaves of good substance, mottled in white and gray-green. Unlike other cultivars, the leaves of 'Pennockii' are carried vertically, which makes a far more pleasing pattern on a three-foot shrub, the ideal size. To grow a fine specimen of 'Pennockii', very high humidity and tropical bright sunlight are essential: Growing it as a house plant is a challenge. 

The names of the so-called roseleaf aralias are also in flux. You may find them labeled P. paniculata, P. filicifolia or P. guilfoylei (some sources consider the latter two separate species). P. guilfoylei 'Marginata' and 'Variegata' grow to eight feet in height and have long-stalked, compound leaves with five oval, sharply toothed, two- to three-inch leaflets. The leaf may be a foot long. In the wild the shrub has a diffuse habit and is not attractive when small, seeming to be all branch. Big plants are very showy, however. 

I did not know of P. crispata until Lynn McKamey sent me a plant with the additional cultivar identification 'Ruffles'. I liked it at first sight for its lime-green color and solid foliage covering, along with its sturdy, compact growth. One might be tempted to identify the plant as a flat-leaved Ming aralia. But seen close up, the irregularly toothed leaflets are somewhat confused in form, some approximately oval, others three-lobed, with the side lobes broad and the middle one narrow and short. 'Ruffles' is very easy to maintain. It is an excellent houseplant and can be trained into an interesting bonsai specimen. 

When buying polyscias, would-be growers should realize that although price alone is not a measure of quality, low price is often directly related to poor selection and worse culture. Usually, physical appearance supplies evidence of forcing, though poor condition is easier to recognize if one has had some previous experience with healthy plants. Compared with healthy specimens, poor ones have leaves that are blemished, lighter in color and thinner in texture. Stems are weak and pulpy, with joints further apart than normal; branches are overlong. More than likely the soil will be muck or a low-grade mix. Soil pests may be evident: They will rise to the surface if the plant is watered. Knocking the plant out of its pot will reveal weakly developed roots. 

Easy-care Ornamentals  

The cultural needs of polyscias are minimal. A soil rich in peat is preferred, although other soils are acceptable. Little fertilizer is required; a regular dose of a high-nitrate formula once a month is ample. Roots are fine and do not spread far, so it is not a good idea to over-pot. Neglect of watering will cause the loss of leaves, but the plants can stand some drought without permanent damage and grow new leaves very quickly. On the other hand, they will not tolerate wet feet for long. 

These are tropical plants, and although they remain unharmed at high temperatures, they do best in an environment with a minimum of 60 degrees F. They will endure cold down to 40 degrees F but for only a very short time. 

My plants have never been attacked by pests even when other species close by were infested. Though some cultivars may be more vulnerable to attack, the whole genus seems to be resistant. Nor have I seen any signs of fungus infections, other than root rot due to excessive watering. 

Propagation is easy and quick. My own plants are all progeny of plants I acquired at least 15 years ago and from which I have given away I don't know how many rooted cuttings. It is preferable to carry out propagation in summer and at temperatures above 72 degrees. Cuttings are usually derived from normal trimming. Remove leaves from the lowest joints of the cuttings, dip bottom tips in hormone powder, and plant, several to a small pot, in sterile house-plant mix. Enclosing the pot in a plastic bag hastens rooting. It is not unusual to find roots in a week. I have also rooted cuttings simply by dangling them in a container of water. One rarely loses transplants. 

The choice of foliage house plants in florist shops and most nurseries is quite limited. Great numbers of only a handful of species and cultivars are available. As one plant falls from grace, another usually turns up in the market, with the total number substantially unchanged. And this occurs despite our increasing knowledge of tropical material and experience with growing it. 

Poverty of choice is due, at least in part, to the effects of competition, but that is not the whole story. As in every other aspect of interior decoration, fads in plants come and go rapidly. The demand for mere novelty appears insatiable. 

The variety of house plants available would be greatly increased if loyalty to truly useful and adaptable plants could be encouraged -- good ones should not be allowed to fall by the wayside. The polyscias, in particular, will not be easily matched -- they have all the qualities we expect of house plants. 
 
~~~~~~~~~~~~~~~~~ 
 
ABOUT THE AUTHOR: 

The late George Elbert, with his wife Virginia Fowler Elbert, wrote numerous books on growing plants indoors. Virginia is still very involved in the publishing world.  

Garden, copyright 1988 New York Botanical Garden  

PRODIGAL POLYSCIAS' RETURN was originally published in the January/February 1988 issue of "Garden" of The New York Botanical Garden, Bronx, New York, 10458. Further information about NYBG is available on its web site at http://www.nybg.org  

This article was scanned and uploaded by Lynn McKamey with permission from Karl Lauby of the New York Botanical Garden and Virginia Elbert.   

Photos are copyright 1988 Rhapis Gardens/Lynn McKamey; driftwood Bonsai photos are by Paul H. Wright.

The following holds several additional bits of information which may help keep your Ming Aralias in top growing condition: 

Watering:  Mings do not like "wet feet" and prefer to become almost dry between thorough waterings.  Do not keep them continuously wet.  We water ours twice each watering - once to remoisterize the soil, and a second time about 5 minutes later to be sure the entire root mass is completely watered.  Then we allow the soil to become almost dry again before watering. 
 
Soil:  Mings need a well drained soil, preferably peat-based and light since they have such small, fine roots.  Heavy, slow draining soils can be killers.  Also, do not neglect to check the soil every year or so since it can "wear out", become loaded in salts if you have poor quality water, or start turning "boggy". 

When your plant is almost dry and ready to be watered, gently tap it out of the pot and examine the root system.  You should see light or white roots throughout the root mass.  Gently remove some of the soil at the top, along the sides, and bottom without disturbing the roots any more than necessary.  If it was root bound, then choose a new pot only slightly larger than the old one.  Add some new fresh soil to the bottom of the pot, and replant finishing with some new soil to raise the soil line back to the original level.  Water three times in a row to thoroughly saturate the new soil and the old. 

If you see dark, unhealthy roots, then the plant may need to be repotted in a smaller container.  Match the pot size to the root system and do not over-pot. 

I am constantly amazed at the people who call me, in a panic because their old cherished Aralia is suddenly dropping leaves and dying.  When quizzed, they tell me that they may have had the plant several years, but never repotted it or given it fresh soil.  This is like wearing the same clothes for several years and never washing them!  Check your plant from top to bottom every year or so. 

Sudden Leaf Drop:  If you've had your Aralia for quite a while (with no problems) and it suddenly starts dropping leaves, don't panic yet.  Is it getting new leaves at the tips?  If so, then this is a routine leaf drop (just like your yard trees each year) and it should grow new ones back very quicky - this may not happen in the fall - we've seen it happen in the spring and various times of the year.  If you do not see new growth anywhere, then I suspect the soil has become old and salty and is killing your Aralia. 

If you've just purchased your Aralia from the local garden center and it is starting to drop leaves (shattering as George calls it), then it is probably because it was grown in high light by a nursery (see the article above for more about this).  Seldom can a "sun grown" Aralia adapt to indoor conditions, however, if you have a warm sunny spot in your house, move it there and hope it slowly adapts. 

Fertilizer:  Contrary to what the label on your houseplant food says, indoor foliage plants do not need much fertilizer, certainly NOT with every watering!  (You don't fertilize your lawn every time you water do you?).  Our guideline is to fertilize at 1/2 recommended dose three times a year - once in spring, mid summer, and early fall.  If you detect NEW leaves turning slightly yellow, then another dose of fertilizer may be in order.  If leaves are nice and green, then they don't need extra fertilizer. 

Propagation: It may not be as easy as George explains above - he definitely had a green thumb!  I agree that summer is the best time; most Aralias will not root during winter since they are semi-dormant. 
 
To make a tip cutting, snip just above a leaf on a stalk or cane (do not cut below the lowest leaf and leave a bare stalk or branch since the whole thing might die back!)  After you've pruned your Aralia plant, then prepare the cuttings by retrimming to have only about 3" to 4" of stalk.  Then remove all except a few leaves at the tip of the cutting (if they are big leaves, then trim them back about halfway).  Prepare a 4" or 5" pot of soil and water it well.  Stick about 4 or 5 cuttings in each pot, then water the soil again.   You will need to mist the cuttings about 4 times a day. George's plastic bag trick will work too for some. 
 
It usually takes 4 or 5 weeks for a pot full of cuttings to grow enough roots to be stable.  You can stop misting at this point.  Root cuttings in the warmest place in your home or greenhouse.  Our own greenhouses are extremely warm in the summer - about 80 at night and almost 100 during the day - good temperatures for rooting Aralias. 
 
Happy growing!  Ming Aralias can live long happy lives with proper care and culture.