Clumping trees in your garden railway

How to group miniature trees together for effect
 ming fern clump with multiple stems
1. What looks like a grove of young pine trees leaning over Mick Limprecht’s Orkney Pass Railroad is actually one ming fern clump with multiple stems (Asparagus macowanii, Zone 9-11). In the upper right is a cluster of dwarf Alberta spruce trees (Picea glauca conica, Zone 3-8).
Nancy Norris
penjing display in the Nanjing Museum of China
2. A group planting at a penjing display in the Nanjing Museum of China exemplifies the freedom from rules to allow the artist’s self-expression.
Nancy Norris
3. Author’s early attempt at a group planting of trident maples (Acer buergerianum, Zone 5-8), intended to be a forest of seven trees, but one gave up the ghost and needs replacing.
Nancy Norris
dwarf boxwoods
4. After five minutes of pruning 6" from the ground, Mike and Anne Paterson’s BSRR’s dwarf boxwoods (Buxus sempervirens suffruticosa, Zone 5-9) are transformed from green globes into real trees with trunks. This 15-year-old boxwood has just revealed its many trunks for the first time. On its right is a multi-trunk Pumila Norway spruce (Picea abies ‘Pumila’, Zone 3-8).
Nancy Norris
dwarf myrtle tree
5. The park in Bob and Sandy Rauperstrauch’s Clear Water Railroad wouldn’t have the same hometown feel without the shade of the spreading dwarf myrtle tree (Myrtus communis ‘Compacta’, Zone 8-10). By pruning the bottom twigs away to reveal multiple trunks, the figures below are lit up and we can see through the tree to the scene across the street.
Nancy Norris
dwarf Korean lilac
6. Micro-miniature roses brighten the park in Ed and Rich Abate’s Rooster Creek Railroad. Cutting back older stems with spent flowers stimulates the sprouting of new stems for continuous blooming all season.
Nancy Norris
7. Denise Pitsch’s Addison Ave. Railroad abounds in gardeny masses of perennials, topped off with an exquisite dwarf Korean lilac clump in full bloom (Syringa meyeri ‘Palibin’, Zone 3-7, thriving in Zone 9). It would be a crime to make this compact and spreading plant into a single-stem tree and forego all those tiny fragrant flowers. It only needs to be deadheaded after blooming.
Nancy Norris
When trains disappear behind a mountain or into the roundhouse, certain trees become center stage in the garden railway. For me, the bridges and buildings are there to show these plants off and add scale. Last issue's column, "Mass planting to frame a focal point," discussed how mass plantings set the stage. We can use clumping trees to shine as focal points or as supporting roles in a scene. Photo 1 shows two ways to create a grove: plant a multiple-stem shrub or tree (left) or group individual trees (right). In both cases, the lowest leaves and branches need to be removed to reveal the heart of the plant, the connection between earth and sky-the trunks.

Imagine a ripening pine cone falling away from its parent, seeds scattering and sprouting to form a cluster of trees jockeying for space in a clearing. Imagine a tree, snapped and felled in a storm, only to sprout many new trunks radiating from one root system. Imagine a seedling with a damaged leading apex or tip, which then forms two or more leaders; and we come back years later to find a tree with double or triple trunks. We can model nature. Two schools of art have been modeling groves of trees for over 1,000 years.

Bonsai vs. penjing

On one hand, the Japanese art of bonsai (literally, tree in a pot) respects natural "order" by following prescribed rules: use an uneven number of trees in a group to prevent symmetry; create the illusion of a deep forest by placing strong trunked, tall trees in front and spindly stemmed, smaller trees in back; slant your treetops away from the center a bit to unify the roots and show the trees reaching for the sun; and, lastly, when viewing from the "front," don't hide any tree trunk behind another. Bonsai is usually about creating an ideal tree, but here you can use less-than-perfect trees in a group to hide deficiencies, because the branches intermingle.

The Chinese present a second opinion in their art of penjing (meaning landscape in a pot). Penjing replicates a broader scenery than bonsai, just as we do in our railway design. Emphasis is on the relationship between the elements, rather than the highlighting of a single element. How do the trees relate to the plants and moss and stones around them? How do you find the best location for each element so that they play off each other, the structures, figures, and passing trains? It's a personal, introspective journey. Still, beauty is the desired result, but as seen through the eyes of the artist in trying to make a "believable" landscape. The penjing in photo 2 proves that an even number of trees (four) can work by grouping three, then adding a smaller one.

My own embarrassing attempt to create a grove started years ago (photo 3), with seven (uneven number) trident maples. One has long since died, so I now call it a penjing instead of bonsai in defense of my "self-expression," because of the current even-number of trees.

Trees vs. shrubs

If you feel it's too fussy to plot out and maintain a planned community of trees, there is a simpler way to get a clump look. Many dwarf, woody shrubs with small leaves can be pruned to show their legs. Often it's a quick fix, as in photo 4-just remove everything green up to the point at which you decide the branches should start. I've seen branches start at 2" or 12" from the ground, and places in between. I generally look at these factors: I use the full-scale tree I am modeling to see how high branches begin; then I look around the little tree's neighborhood to see if I need to keep branches low to hide something or raise the canopy to expose something; and, whenever possible, I take a little time to "open it up."

Opening up a tree is an art in itself-a performance art, if you've ever watched an arborist at work. To make a shrub less bushy, I try to remove whole branches inside to allow light, water, and air to get in, and it's healthy for your plant. While this is an important lesson for another time, you can see an example in this issue's "Plant portraits," a Lawson's false cypress; it is transformed from bush to tree. If you want to keep it bushy and dense, just prune the top and sides (called "pinching"), which will stimulate many new, short branches. These are living trees so you'll get many opportunities to change your style.

To break up the look of sameness in your railway, try a clump of trees. It may be just the thing that's needed and not as difficult as you think. Conversely, if you feel your railway needs unifying, literally pull together like elements and make a group planting.

Some plants spread on their own and continue to make new stems: micro-miniature roses, for instance (photo 6). Prune them after they bloom or you'll end up with lots of dead wood at the end of the season. Thinning out some of these dead canes at ground level takes away the scruffy look and restores the cared-for look roses deserve.

Sometimes an area behind the shed or next to the foundry calls for scrub bushes, so multiple stemmed, shrubby trees work there. Occasionally we run across a spreading bush with everything-sturdy, woody stems bearing low profile, little leaves, and gorgeous flowers, complete with perfume. An example of this is the dwarf Korean lilac (photo 7). It's easy to maintain; just clip off the spent flowers, shape it a bit, and keep the legs exposed.

It's good to have a starting point by looking to see what others have done. Yet, some of the most original ideas come from those who are not schooled, but bravely try their hand at new techniques. A grove of trees creates its own focal point but I like to enhance the scene with an animal or hiker, and maybe a pathway. Viewers pause, absorb the dynamics of the scene mentally, then take an inspirational walk in the woods.
A multi-trunk Crassula sarcocaulis ‘Ken Aslet’, Zone 9-10 (Feb. 2008 GR “Plant portrait”) brushes the top of Chug on the F&DRR.
Frank Lucas
It takes only a few years for Seiju elms (Ulmus parvifolia ‘Seiju’, Zone 5-10) to grow stout trunks with intriguing, corky fissures in the bark. Grouping them calls attention to this feature on the Mystic Mountain Railroad.
Ray Turner
No wonder the little tourist is taking a picture of this leaning artistic dwarf myrtle (Myrtus communis ‘Compacta’, Zone 8-10) in the Hoags’ Wild Eagle Railroad. Patience even left a dead branch twisting with its mates.
Patience Hoag
Regional gardening reports
Zones listed are USDA Hardiness Zones

Question: How have you grouped or pruned your trees to create a multi-stem clump?

Ray Turner
San Jose, California, Zone 9
Old oaks in elm clothing
I have a grove of Seiju elm trees that are about eight years old now. They have developed beautiful gnarled trunks, a great part of their appeal. Each winter they drop their tiny leaves and I have to heavily prune them to open up the inside of the "forest" and to restore the appearance of large, very old, trees. It only takes a little imagination to see 100-year-old oak trees here.

Dick Friedman
Sacramento, California, Zone 9
Keep it simple
This is pretty esoteric stuff for an ol' country boy like me. I didn't even know there were people who obsessed about one trunk or more than one trunk. I'm pretty much at the one-trunk stage. If I can get one trunk to live two seasons, that's a victory! I try to make my little trees look like big trees-and that usually means a single trunk for about six to 10 scale feet, then branching out into a "tree shape" (whatever that means). Some of my micro-mini roses have several trunks, so those I try to get to look like a multi-trunk tree of some type. Don't know if I'll bonsai these puppies but they definitely need to be trimmed back after each blooming.

Patience Hoag
Phoenix, Arizona, Zone 10
Buried treasure
The fact is, I didn't start out knowing much about how to trim the trees. My primary concern back in 1999-2000, when that tree was planted, was to keep it from getting too big and bushy. I tended to do a hatchet job on all the trees, and just take as much "off the top" as was necessary.
After several years (yes, years!) I started to pay a little more attention to the trunk and branches. I began to trim away at each of the trees to discover the unique main branch structure that was buried under the bulk of mini-branches and leaves. For each of my trees, I found the most unusual branches and trimmed the less interesting ones away. Once the basic shape was defined, all I needed to do was continue to keep the growth under control and continue to keep the trunk and main branches well defined.
Now that the trees are so well established, they are easier to maintain. Sometimes, instead of taking a hand pruner to them, I'll just grab and yank off some of the overgrowth. It detaches easily and keeps the trees from looking too "manicured."

Frank Lucas
Pleasant Hill, California, Zone 9
Car wash
We just planted 'Ken Aslet' after picking him up at a pruning clinic. Donna wants to wait until he gets happy in his new home before we do any pruning. Actually, I sort of like it the way it is. The train goes under it, brushing the branches aside, and the plant acts as a sort of car wash, dusting off the detritus of everyday life.


Read and share your comments on this article

Want to leave a comment?

Only registered members of are allowed to leave comments. Registration is FREE and only takes a couple minutes.

Login or Register now.


Get the Garden Railways newsletter delivered to your inbox twice a month

By signing up you may also receive occasional reader surveys and special offers from Garden Railways magazine. Please view our privacy policy