CHINESE ELM ulmus parvifolia - Information & Care Instructions

Posted on 7 Jun 18:30

CHINESE ELM - ulmus ‘parvifolia’

Chinese Elms, also know as Lace Bark Elm, are strong, adaptable, and make a great tree for those just starting out in bonsai. The Chinese Elm is native to East Asia; China, India, Taiwan, Japan, North Korea, and Vietnam. In its natural form, Chinese Elm can grow up to 60 feet
Care for ulmus parvifolia dwarf cultivars; 'Seiju' Catlin & Hokkaido, as relevant to bonsai, are basically the same.
As a Bonsai, Chinese Elm has the unique ability to thrive either indoors or outdoors. It may drop some of its leaves in either situation, since it is semi-deciduous.
Chinese Elms form a graceful rounded canopy with small, dark green leaves, which have a leathery appearance; a shiny top side with small, blunt teeth along the edge.
The trunk has handsome, flaking bark of mottled grays, with tans and reds; this is where it gets it common name, the Lacebark Elm.
Chinese Elm can develop small, inconspicuous, wind-pollinated, flowers in late summer or early autumn. If pollinated, they mature into samara type seed pods instead of fruits. Kept as an indoor bonsai, if flowers do form, they may not pollinate.
U. parvifolia is one of the cold-hardiest of the Chinese elm species; it is winter hardy to about zone 5 with protection.  However, as a bonsai we do not recommend it as an outdoor plant in area’s of the country with long cold winters. 
One of the advantages to growing a Chinese Elm bonsai tree is that, unlike many other elm trees, it is not prone to Dutch elm disease; considered resistant, not immune.

How To Take Proper Care Of Your Indoor Bonsai Tree

Bonsai is the reproduction of natural tree forms in miniature. This art form has its origin in Japan and China where it has been practiced for centuries. Bonsai are grown in pots and are totally dependent on you for their care.
With proper care, your bonsai will remain healthy, beautiful and miniature for many years to come. Since your bonsai is a living miniature tree, it will increase in beauty as it matures through the years. The instructions below are just the basics and, therefore, we recommend that you purchase one of the many fine books available on the subject.

The Chinese Elm will thrive indoors in high light and appreciates being kept outdoors during the spring and summer.  When night time temperatures drop below 45 degrees we suggest that you move the tree indoors and place on a windowsill or on a table in front of one.

Once nightly lows begin approaching the 45 degree mark, it is time to bring your indoor bonsai inside. The ideal indoor location is on a window sill facing south. An east or west exposure is second best. A northern exposure will work, but will necessitate the use of "grow lights" to provide sufficient light to keep your bonsai healthy.  Four to six hours of sunlight per day should suffice.  If you can provide more light, even better.

Watering of your bonsai must never be neglected. Apply water before the soil appears dry; never allow the soil to become completely dry.  Water should be applied until it begins running out of the holes in the bottom of your pot. It doesn’t really matter “how” you water your tree, but rather that when you are finished the tree has been well watered.
If you are inexperienced with Bonsai, it is a good idea to use a moisture meter until you get to know the requirements of your bonsai tree.

During the cold months, when your bonsai is inside, we recommend placing it in a shallow tray filled with a layer of gravel with water added (The bottom of the pot should sit above the gravel). This provides extra moisture around the tree as the water evaporates, compensating for the moisture lost to modern heating systems.
You may want to use an Humidity Drip Tray outdoors; in areas of the country where humidity tends to be low; or for local moisture during heat in the summer.

Fertilizing is also necessary if your bonsai is to remain healthy and beautiful. Since your bonsai is growing in such a small amount of soil it is necessary to replenish the soil's supply of nutrients periodically.
Any general-purpose liquid fertilizer will do fine and are available at most garden centers. Which ever type you choose we suggest diluting / mixing the fertilizer to half the recommended strength.
Fertilizer should be applied at least once a month, except during winter. Your bonsai will also respond well to foliar feeding, with a water-soluble fertilizer applied every other month as a spray.

This brief explanation of basic care does not cover training. Training deals with the art of bonsai and should be thoroughly understood before undertaking or left to a professional. However, most of the true bonsai trees you find have already been through their training period, thus requiring only periodic trimming and pinching to remain miniature.

Trimming and pinching keep your tree miniature. Pinch and trim back the new growth to the farthest safe point. Never remove all of the new growth; a little needs to be left, to sustain the health of the tree. Since different trees grow at different rates, it is necessary to evaluate each tree’s rate of growth and adjust your trimming and pinching to accommodate it.

Repotting must be performed periodically on all bonsai when their root system has filled the pot. The reasons for repotting are to supply your tree with fresh soil, and to encourage a more compact root system. Since trees grow at different rates, you should examine your tree's root system every year or two to determine if it has become pot-bound.
In most cases, the potting process is easy and safe if performed properly and at the right time of the year. Repotting should be done in mid-summer.
The tree, along with all of its soil, should be removed from the pot. The outer and bottom most fourth of the tree's root mass should be removed. This is done by raking the soil away, then pruning back the roots. In most cases, it is not good to prune back more than one fourth of the tree's root mass. After this, the tree can be placed back in its original pot or into another.
The pot should have screen placed over the drainage holes. Then a thin layer of small gravel is placed in the bottom of the pot for drainage purposes. On top of this gravel is placed the new fresh soil. Place a layer of well-draining soil which is sufficient enough to elevate the tree to its previous height in the pot. After placing the tree back in the pot, the area left vacant by the pruned root mass should be filled in with fresh soil. This fresh soil should be worked in around and under the root mass in such a manner as to avoid leaving any air pockets. After repotting, your bonsai should be thoroughly watered. This can be achieved by submerging the entire pot in a tub of water. Moss or other ground covers can be used to cover the surface of the pot to help prevent soil erosion when watering.

Since your bonsai is a tree in miniature, it can be treated for insects and diseases the same as any other tree. If you discover any insects or diseases, visit our website where you will be able to obtain the necessary products to eliminate the problem.