Conifers From Yucca Stalks

Bob Hyman

Note:  There is some additional clinic information contained in the original handout that is not included in this HTML version.  To download the original clinic handout document in Portable Document File (.pdf) format, just click here: Conifer Clinic.pdf (179 K Bytes) .

Section 1 – Introduction 

It would be hard to imagine a narrow gauge railroad without conifers. These magnificent plants are so common that we tend to take them for granted. Like many of you, I have tried numerous methods for populating my scenery with model conifers. The key is to find one that yields realistic results, is relatively inexpensive, and easy to do. The method described in this clinic meets all three requirements.

In this handout, you will learn about real conifers and how to make realistic models of them using Yucca flower stalks for the trunks. Yucca is a common plant found throughout the United States, but particularly plentiful in the west. A description of Yuccas and information on collecting the stalks was included in my article "Yucca Plants Make Great Conifers",  published in the Fall/Winter 1999 issue of Sn3 Modeler Magazine.

Section 2 – Conifer Basics

    A primer for the non-botanist.

Gymnosperms, the familiar coniferous, needle-leafed trees, often called evergreens or conifers, make up one of the two great subdivisions of the seed-bearing plants. The other subdivision, Angiosperms, includes the broad-leaved, deciduous tree forms – the so-called hardwoods. Conifers manifest a striking range of variation in structure, habit, size, and longevity.

Coniferous Forests

The most widespread forests of North America are those of conifers or softwoods – the cone-bearing evergreen trees with small leaves shaped liked needles and scales. Within the United States, main geographic types are the northern coniferous forest, the Pacific Coast coniferous forest, and the Rocky Mountain coniferous forest.

Northern coniferous forests, sometimes called "north woods", range from Alaska and Canada down into the northern U.S. Tree heights vary from 100 feet down to about 20 feet, decreasing northward towards the tundra areas. Eight species compose this forest: white spruce, black spruce, balsam fir, jack pine, tamarack, paper birch, balsam poplar and quaking aspen.

Along the humid, cool northwest Pacific coast of America, from Alaska down into northern California, is the greatest stand of timber on earth. It is the densest, tallest, most magnificent, and most valuable. Giant evergreens typically grow from 200 to 250 feet high and from 5 to 8 feet in trunk diameter. Some reach over 350 feet high or 30 feet in trunk diameter. Major species include western hemlock, Sitka spruce, Lawson cypress, redwood, Douglas-fir, western white pine, sugar pine, ponderosa pine, and Jeffrey pine.

The Rocky Mountains from Canada south into Mexico have coniferous forests in altitudinal zones. Evergreen trees typically range from 40 to 150 feet in height with trunk diameters from 1 to 4 feet. Lodgepole Pine is common throughout the northern Rockies in dense stands of medium-sized trees on burned areas. At the timberline is the subalpine spruce-fir forest of Englemann Spruce and subalpine fir. Douglas-fir, often with aspens, occupies the next lower zone. Southward, especially into Arizona and New Mexico, are open forests of ponderosa pine. At lower altitudes is the pinyon-juniper woodland, composed of scattered dwarf nut pines called pinyons, and junipers, shrubby rounded trees usually less than 20 feet high.

Coniferous Tree Parameters

To a modeler, the six most important parameters of a conifer are size, shape, color, texture, habitat, and range. Size includes the total tree height, the trunk diameter, and even the size of the cones. Shape includes the branching pattern, general foliage outline, and crown configuration. Color includes the trunk, branches, twigs, and cones. Texture includes the bark and foliage. Modelers must also be aware of growth habitats and range to create realistic model trees that are appropriate for the layout and to locate them in appropriate settings.

Size. Trees are probably the most under-scaled item on any model railroad. In S scale, a model of a mature 130-foot ponderosa pine tree should be about 24" high, 4" wide, with a trunk diameter of 3/4" and with cones about 3/32" long. In HO scale, a model of a mature 160 foot sugar pine tree should be about 21" high, 3" wide, with a trunk diameter of 5/8" and cones about 3/16" long.

Shape. Conifers come in a wide variety of shapes. Some are tall and cylindrical; others are pyramidal or cone shaped. Crown foliage varies from sharply pointed to flat. Some conifers are light and open; others extremely dense. Trees on slopes and in protected groves are generally symmetrical unless crowded; near the timberline they are windswept and often grotesquely gnarled. Trunks may rise straight up or may be sharply tapered. Some trunks have heavily buttressed or spreading bases. Branching patterns may be flat horizontal, pendulous, or upswept. Patterns may vary widely within the same tree between lower and upper branches. Some conifers are branched to the ground; others show a large expanse of bare trunk between ground level and the lowest branch. Cones may point up, or may hang down. Some are on uppermost branches only, at branch ends; others dispersed throughout the foliage.

Color. Conifer foliage ranges from steely gray-blue, through blue, blue-green, dark green, green, to yellow-green. Needles may be of different colors on upper and lower edges. The individual needles may also have whitish or yellowish stripes, which, from a distance, impart a characteristic hue to the foliage. New growth may be of a different color than the older needles. Cones, which may be cylindrical, egg-shaped, or berry-like, vary from brown, through all shades of reddish-brown and yellow-brown to purple, red, and blue. Trunks, branches, and twigs vary from blackish-brown, through brown, reddish-brown and gray-brown, to gray and whitish-gray.

Texture. Bark texture may be smooth, ridged, deeply furrowed, fibrous, or plated. Foliage texture includes needle-like and scaly types of leaves. Needles may be round, flat, or angular. Foliage texture is also influenced by length of needles, which range from ½" to 12". The foliage may be sharp and prickly or soft and pliant.

Habitat. Conifers grow either in pure stands or mixed forests. In the pure stands, all trees are of the same species and are uniformly sized. Pure stands may be small groves or entire forests encompassing many square miles. Mixed forests include varying species. Some conifers, like those in the Rocky Mountain coniferous forest, reach maturity in less than 100 years. Others, in the Pacific Coast coniferous forests may take 400 - 600 years. Some conifers are over 4,000 years old, such as the sequoias and bristlecone pines. Conifers are greatly influenced by fires; in fact, some species require fires to reproduce. Forests are also dynamic. They go through stages after fires, disease, or clearing; some plant species recover quickly, then give way to others. Modelers should not be too greatly influenced by what a particular prototype scene looks like today; the species there may have changed significantly since the period being modeled.

Range. Some conifers are unique to the Pacific Coast or to the Rocky Mountains. Others exist in both locales, sometimes with slightly different growth characteristics.

Conifer Names

Botanists group conifers into several families that share similar characteristics. These include the Yew, Pine, Redwood, and Cypress families. Each family is a collection of Genera (singular: Genus), which further subdivide the conifers. For example, the Pine family is composed of several Genera including the pines (Pinus), larches (Larix), spruces (Picea), hemlocks (Tsuga), firs (Abies), and Douglas-firs (Pseudotsuga). Each Genera is composed of several closely related species.

Each conifer has at least two names, a common name and a scientific name. Common names may vary locally, but the scientific name is used uniformly throughout the world. The scientific name is composed of two parts. The first word, always capitalized, is the Genus; the second word, not capitalized, is the species.

Section 3 - Tips for Realistic Model Conifers

    Read this section before you start making trees!

Since real conifers vary tremendously in size, color and shape, it can be difficult to create an accurate model. In addition to the wide variations of actual color on the trunk, needles and cones, other factors influence how we see conifers. Moss and lichen may accumulate on the bark, giving a greenish cast to the trunks. Trees may ooze resin or sap, causing trunks to glisten. Texture and color variations in the bark, needles and cones can affect our overall perception.

Perceived conifer color is also dependent on numerous other factors such as:

To further complicate matters, the modeled conifer seldom is viewed under ideal artificial light which replicates true outdoor lighting conditions. The bottom line is – simply stated – it is neither possible nor desirable to duplicate a real conifer’s color in a model. It is, however, possible to create realistic model conifers by adhering to the following principles:

Modeling the appropriate species means more than just not putting Redwoods or Sugar Pines on the Ophir Loop. It includes knowing the correct habitat and range for each of the conifers that you model.

Choosing correct shapes and sizes means using the proper profile and branch patterns. It also means using a variety of heights and ages for each species, and creating randomly interspersed models of young, intermediate, mature, dying, dead and fallen trees. Don’t forget the leaning, contorted, doubled-trunk, burnt, broken, or lightning-struck specimens either. Don’t be afraid to make scale-sized conifers. It is hard to break the mindset of using undersized, uniformly shaped and colored trees but, once you do, you will find that your modeling looks much more realistic.

By varying textures in your model conifers, you create more-interesting subjects for the viewer. Try to re-create – even exaggerate – the bark and foliage textures. Use the standard artist’s tricks of adding-in artificial texture details, shadows and highlights.

Use the full range of applicable colors. For example, if the real conifer has yellow-green foliage, don’t limit your model to a single shade of yellow-green. Use every variation of yellow-green you can come up with. Keep in mind that every color is composed of three components: hue, intensity and value. Vary the intensities and values as much as possible to add visual interest. Remember that errors in choice of hue are far less serious than in choices of intensity or value. (For more information on color, see my "Understanding and Using Color" article in the articles section of this web site Color Theory.)

And finally, experiment with sensory "tricks" to fool the viewer’s perception of the model. Use pine scent on the trunks. Spray the foliage with pine-scented air freshener. Plant trees in odd-numbered groups, e.g., 1,3,5,7, etc. Use irregular, random spacing between trees. Use the "rule of threes" – use a given color or texture three different times in three different places. The viewer’s eye will subconsciously connect the three points, and jump from point to point, creating visual interest. Use special "spotlight" lighting to emphasize a special tree or grouping.

Above all, don’t create a model conifer based on what you think real conifers look like. Go out and observe real conifers, or – better yet – get a good reference book on trees and use it. (For more information on conifers, see my "Conifers" article in the articles section of this web site Conifers.)

Section 4 -- Safety Precautions

    Mostly common sense, but worth a reminder!

Section 5 – Tools Required

    Just simple stuff … nothing out of the ordinary.

Section 6 – Materials Required

    What you will need, and where you can find it.

    So simple, even an HOn³ modeler can do it!

General Notes: 

Prepare Trunks:

Prepare Branch Material:

Apply Branch Material To Trunk:

Add foliage:

Add Individual Dead Branches (Skip if branches go all the way to the ground):

Plant Your New Conifer and Enjoy:

Special Note: Although these instructions were intended for Sn³ modelers, the techniques are equally applicable for modelers in other scales – just adjust the sizes accordingly. For you non-Sn³ modelers, there is one additional step: