Maximum size of tree on an HO layout.

I was wondering…Is there a maximum size for trees on an HO layout? I have one of the Woodland Scenics realistic tree kits that has 3/4"-3" trees. They look cool, but they look small.

Also, since I’m building my first layout, when it comes to trees, is more better? I have a hill that covers 2 tracks ( an area of about 2’x6’). It already has a couple of small outcroppings and grass but I can’t decide on whether or not to put alot of trees on the hill.

I guess it would depend on the species of tree you’re trying to emulate. For example, a 45 foot tall pine tree would be 6.20 inches tall in HO scale…to figure out how tall the trees should be, simply divide 12 by 87. Then multiply that number by how many feet tall you want the tree to be and you’ll have your answer in inches.

Don Z.

Many common species of trees reach 80 to 100 feet tall at maturity. That correlates to about 1 foot tall in HO scale. However, modelers often use selective compression in HO scale, making buildings and other features smaller than real life, making the building footprints smaller than the prototype and roads narrower than true HO scale . Trees that have not been compressed accordingly will look out of place. The important thing is constancy. Just experiment with what looks good. I would think you should keep your tallest trees around 8 inches, but that is just off-the-cuff. I would get some trees of various sizes and experiment with what looks right to the eye.

The right size tree, like so many other things, depends on the prototype. In West Texas, a 3" (HO scale 22’) tree would be a giant. In coastal Oregon it would be underbrush.

Those itsy-bitsy trees could be new plantings in a raw subdivision, or what’s starting to grow back after Paul Bunyan and Company clearcut the old growth forest. Or they could be as big as they’re ever likely to get out among the tumbleweeds.

As for really big trees on a model railroad, check the picture on page 63 of the Feb '06 Model Railroader. The foliage is against the ceiling, and some of those trunks hide the rods that support that scene.

I’m not modeling any specific geographical area, but plan on using a majority of deciduous trees. I do plan on using tall pines, but only here and there, along with some Scenic Express Super Trees to emulate poplars.

I tend to agree that most ready-to-use and “kit” trees in HO are a little small. I typically see them 2-4" tall which is 14-30’ tall in scale. Yes, there are plenty of 14-30’ trees in reality, but also (in many areas) plenty far taller than that.

Selective compression does play a role, but I still think the typical tree is a little on the short side.

My practice, just from observing reality, is for trees in a mature area (i.e. not a new development or such) to be about the same height as a 3-story building, on average. Maybe the occasional older pine or oak higher than that, and some saplings shorter. So if I’m using compression on the buildings, the scale of the trees becomes self-correcting…

Now that’s general “shade” trees and pine trees in suburban/urban areas. Obviously species plays a role. For instance, a 4" tall dogwood would be silly… far too tall.

Scene also plays a role. I have several areas on the layout of forest-covered hillside. Here, only the first row or two of trees are even fully modeled, the rest are essentially blobs of flock-covered base material stuck directly to the ground. You’re dealing in almost complete illusion in that case… Or spending a fortune modeling a forest entirely in full-blown trees that won’t be much seen anyhow.