by Rick Daugherty

This article was first published in the April 1999 newsletter - Ed.

As a beginner in the art of bonsai, purchasing an "established" bonsai can be a gratifying, yet potentially costly experience. However, creating a bonsai from scratch can be a very rewarding learning experience. It won't cost you as much and it's not that hard to learn what to look for when selecting potensai.

Potensai is a term used to describe "potential bonsai" plant material. These little gems can be found at your local bonsai store, garden center or nursery. But you've got to know what to look for, and you must possess the ability to look into the future . Due to space limitations, this article will deal with only "outside" trees - those that are hardy in our part of the country (more on that later).

What's the difference between a common shrub or tree and a "potensai"? The answer is two-sided: on one hand, there's very little difference between the two, as a nice bonsai can be developed from a common landscaping plant (see the following list of common plants suitable for bonsai). On the other hand, just because you've found a plant that is on the list doesn't mean it will make good bonsai. There are certain characteristics you need to look for when making your selection. If you're purchasing potensai from a bonsai store or online nursery, most any of the plants offered will probably lend themselves well to bonsai. But you'll most likely pay more than you would from another source.

Another term to look for when shopping at a bonsai store is, "Pre-Bonsai". This is different from "Potensai". Pre-bonsai have been taken one or more steps further toward a styled tree. The plant may have already had its root mass reduced over a period of years to begin the process of fitting it into a shallow pot. Or its branches may have been pruned to begin the shaping process. This material will be much less expensive than an "established" bonsai, but will undoubtedly cost more than potensai. But let's limit this discussion to potensai - plant material you can find virtually anywhere in 1, 3 or 5 gallon nursery pots.

First, you'll need to do a little homework. Buy or borrow books on bonsai. Look at the trees and familiarize yourself with what a bonsai looks like. Take the books with you to the nursery.

Many bonsai books list common plant material that's suitable for bonsai. The books often include care instructions for each in a reference section. Refer to this section when making your choice. Pay special attention to the hardiness of the plant. Hardiness refers to the plant's ability to withstand a range of temperatures, light, and water conditions. Hardiness is often classified as USDA Hardiness Zones. The higher the number, the less cold the plant will tolerate - Zone 9 being the deep southern regions of the U.S. and Zone 3 being the colder areas such as states on the Canadian border. The zone for our area, Kentuckiana, is between zones 5 and 6. Didn't know you'd have to be a mathematician to take up bonsai as a hobby? Don't worry - it's not rocket science... follow me...

Let's say you've found a wonderful Eastern Larch (Larix laricina). You've fallen in love with the small, feathery, emerald green, spring needles. And the thick, tapering trunk is to die for. And at only $34.95, it's a steal. Right? Wrong. Refer to your books. The tree is indigenous to the northern-most states of the U.S. and Canada, zones 1-3. So it will love the occasional frigid temperatures we experience in the winter. But consider our summers... humid, heat sometimes pushing into the high 90's if not 100! If you're really lucky and the weather is real mild all summer, the larch may survive the first year. However, chances are it will be a crispy critter by the following fall and you've wasted $34.95! This species simply cannot tolerate Ohio River valley conditions for any length of time. So don't buy it, move on to a better-suited plant.

The opposite end of the spectrum is just as valid. Ficus are grown outdoors year-round in some parts of Florida. However, leave a ficus outside in our area and it will drop dead after the night time temps begin to drop consistently below about 50 degrees F.

So, when purchasing an outdoor bonsai candidate, a good rule of thumb to follow is to consider what grows well in the yards of Kentuckiana. You can attempt to deviate with plants that are indigenous to regions a couple hundred miles north or south of our area with differing success. Read your books for specifics!

Don your knee-pads, let's go!

In order to determine what specimens of shrubs are better suited to bonsai than others, you're going to spend a lot of time on your knees at nurseries. You might also want to consider lightweight gloves, you'll understand why the first time you lift the foliage on a San Jose Juniper to examine the roots and trunk.

Selecting a specimen is not as simple as determining what type of shrub will live in our area. When making your choice, there are certain attributes or "rules of bonsai" that you should consider.

General health of the specimen

As a beginner, you'll have your hands full trying to develop your specimen into a bonsai that suits you.

Most every source of plant material has a "scratch-and-dent" section in which they offer material at greatly reduced prices. Often, the material is in very bad shape. The trunk is gnarled, the foliage is weak, or it's pot-bound. In all actuality, it may be perfect for bonsai. But probably NOT for the beginner! Buy it if you'd like, but your experience level will probably NOT be able to keep it alive and you'll waste your money. Read your books, ask questions, learn how to eliminate pests and bring a tree back from near death, and several years from now, seek out those specimens. But for now, consider only healthy specimens, ones that exhibit good, green foliage.

Nebari

Nebari is a Japanese term that refers to, the visible surface roots of a tree. Remember, a bonsai doesn't have to be old. It only has to "appear" to be old. Strong, radiating, surface roots imply that a tree is solidly anchored in the ground. Most young nursery specimens do not possess this quality, but some do. For instance, maples (the Acer family) can develop wonderfully large, radiating roots at a young age. But junipers probably won't exhibit this quality early on.

The nebari can be corrected over the coming years, but that's a topic for another article and is best left to a period after you've better honed your skills as a a bonsai artist.

Trunk width

Very important, but this depends on the species you've chosen. My experience has shown, that for every 100 trees I look at, only ONE has a good-sized trunk! If you walk into a garden center and the first 10 trees of a particular species you look at have a spindly trunk... don't give up. Look at them all! That little treasure you're seeking may be hiding in the back of the pack. More often than not, it's the last of 30 trees! Keep searching!

Trunk Taper

Even if you find a thick trunk, you're only part way through your selection process. The next consideration is trunk taper. Trunk taper is, as the term indicates, the rapid reduction of the trunk size as you examine upwards from the surface roots to the top of the tree. If the trunk starts out at 1" at the root base and only tapers to 3/4", 18" later at the top of the tree... pass it by... it's no more than a stick with foliage on top!

Again, the idea of bonsai is to "imply" age. An old tree which has been ravaged by wind, disease, insects or ice may have had its trunk snapped off or many of its upper branches torn off over the decades. Mother Nature usually tries to recoup her losses by sending out new, thinner growth from these damaged areas. Thus, trunk taper is developed in older trees and is, therefore, a desirable trait in bonsai.

Looking in to the future

For the beginner, this is definitely one of the hardest aspect of choosing a potential tree.

Envisioning the future shape of your tree is much like the exhaustive process of choosing which home to buy... your realtor takes you to a house and the only comment you have is, "I don't like the wallpaper and paint." Unfortunately, you may be missing the best aspects of the home... its basic structure and character. Wallpaper and paint can be changed... the same goes for bonsai. Familiarize yourself with what a good bonsai looks like by reading your books. Then look "past" the existing branches and foliage and find the inner-beauty of the tree. If the plant possesses all the attributes I've referred to: health, cold/heat hardiness, nebari, trunk size and taper AND you like the tree.. buy it! And enjoy the learning experience of finding and creating your own bonsai from scratch!

SUGGESTED PLANT MATERIAL

Juniper (both the Procumbens or San Jose varieties), Holly (any small leafed member), Boxwood (any small leafed variety), Maple (many types), Chinese Elm, Dwarf False Cypress, Spiraea (some of these guys can have wonderful trunks), Barberry, Cotoneaster (numerous varieties), Heavenly Bamboo (not a true bamboo), Spruce (Alberta Spruce make very nice bonsai), Firethorn, Azalea, Wisteria