Native shrubs are by nature survivors. They must, depending on their habitat, be able to tolerate extremes of temperature, animal mutilation, drought and/or flood, and even people! They often make good bonsai material because stress simply makes them try a little harder. They aren't often known for lush, rampant growth as much as their ability to 'bounce back' after a problem that would devastate a pampered shrub in our gardens. They are usually slow growing, often developing trunks that are thick, twisted and gnarled by wind, or animal grazing.
A necessary part of survival must be an ability to reproduce under varied and often less than ideal conditions. This could be seed that is easily dispersed by wind or clinging to animal fur. It could be fruit that is eaten by animals or birds, so seed is dropped some distance from the plant, or evergreen cones picked and stored by squirrels. Some plants reproduce by vegetative reproduction, sending up miniature plants from the root system called 'suckers'. These plants can be removed from the parent plant when they are small, and can become intriguing bonsai.
If we remember our definition that a bonsai is a plant that resembles a large, old tree in miniature, we can more easily create a bonsai from a model we know, rather than an exotic tree we may have never seen. A native plant can have a bonsai style in its native habitat, because something creates the stress that keeps it small, and branch growth is modified by growing conditions. We can create an image of that plant ourselves, under more controlled conditions, as a bonsai.
The plant I used was a Silver buffaloberry (Shepherdia argentea) which is native to dry prairies of Canada and the United States. It has oval, silvery leaves, large thorns, is known to sucker freely (a real nuisance in a manicured lawn!) and survive in spite of all the vagaries of prairie weather. It is also sold as a landscape shrub, because it is not only very hardy, but beautiful as well. There are many other shrubs, in climates somewhat different, that would be equally suitable for bonsai. Many of them are available commercially; others may be able to be found growing wild. A book of native trees and shrubs would be helpful, and information should also be available from garden centers and nurseries.
My shrub had small suckers continually forming underneath it, along the roots. They are fairly easily pruned off, but I let one grow over a whole growing season. The next spring, when tiny buds were just opening, it was relatively easy to remove soil from around this little plant and cut it away from the parent plant's root. I removed the piece of root that it was growing from, and kept some roots with the little plant, particularly the fine, hair roots which are so useful for absorbing water. I potted it in a container large enough to contain the chunk of root easily, with good quality soil, and added some rooting hormone to the water periodically to encourage good root development. During that summer, new leaves formed, and appeared healthy, so it was obvious that the roots were supporting the top growth. It was outside during the summer, in its pot, in a sheltered place away from hot sun and strong wind. This plant didn't need any extra stress right now - survival was a big enough job.
By fall, when the days were becoming shorter and weather getting colder, it was brought into my cold room for the winter. In climates kinder than mine, it could remain outdoors for the winter. The next spring, it was time to create a bonsai from my little baby tree.
Branches were removed where necessary to create an open style where each branch was visible. One branch was wired to force a downward curve, and some of the previous year's growth was shortened. The trunk was very sturdy for the size of the plant, giving an appearance of age. It was placed in a rectangular pot of red, unglazed clay. This appealed to me as representing the habitat where it grew naturally. At this time, it was obvious that many little hair roots had formed on the original piece of root, so some of the thick root was removed and as many fine roots as possible maintained.
The silvery leaves were a wonderful contrast to the pot, where a light colored pot would have been too similar to the leaf color and 'disappeared'. A rock of a similar material was positioned in the soil at the end opposite from where the trunk emerged from the soil. This, too, looked as if it had 'happened', as if it belonged there, under that plant. Many bonsai soil surfaces are covered with moss, but that would have looked out of place here. A light sprinkling of coarse sand on the soil surface completed the image.
After care consists of a bright, sunny spot where it isn't so hot that the soil dries out too quickly, in the summer, and a winter home where it gets quite cold but doesn't freeze. This will vary, depending on the natural growing conditions of the plant. Try to give native plants as close to their natural growing conditions as possible. Native, prairie shrubs need very little fertilizer - they certainly don't get much where they normally live. Perhaps a balanced fertilizer once each spring, because it is in so small a pot, would be helpful, but that would be enough.
Bonsai from native North American shrubs do not necessarily fit our image of traditional bonsai. It is wise to remember that the Japanese did not develop the concept of bonsai in a rigid manner, expecting everyone throughout time to copy them exactly. They used Japanese shrubs because they were there. While there are many beautiful Japanese bonsai for us to use as inspiration, we can use our native plant material in the same way. I hope you enjoy the search as well as the final result.