My wife's grandma is 94. When she was only a few years younger, her eyesight was better and here hands more steady. She used to pass some of her spare time making miniature trees with copper wire and beads. The exact same method works excellently to make trees for dioramas. Here's how you can make diorama trees that are larger than the mini-trees you'll find in a hobby store. They look very convincing. It may look hard at first, but it's really easy.
The whole method consists of making a metal wire skeleton, that can be covered by different methods of your choice to simulate the bark.
You need nine or twelve strands of wire. The length of each strand is easy to calculate : first you decide how high the tree needs to be, then you multiply its heighth with 2,5. (two point five). For example : a tree of 30 cm needs strands of wire of 30 x 2,5 = 75 cm. I use the kind of wire that you'll find in a DIY store or garden center, with a thickness of about 0,5 mm.
Part One : Making the Roots
You cut nine or twelve strands to equal size, and hold them together. You bend the whole bunch in the middle.
Next, you place 3 or 4 fingers (depending on tree size) on the middle section to form a loop around your fingers.
Next, you twist the strands a few times to make this a firm loop.
The loop that you now created, will become the base of the tree's root system. Divide the loop into bunches of one, two, three or four wires each, thus creating separate loops.
Now start twisting each of these loops to form the root system. These roots are placed horizontally: they become the basis of your tree. This basis will be buried in the base of your diorama, or you can even make part of those tree roots visible on top of the grass or soil the tree "grows" in.
Start twisting each of the individual loops a few times, then split them in two or three again and continue twisting till you get a root-like system.
Now the root system starts taking shape. First you spread the roots horizontally in a way that you like, and that seems natural. The roots in this picture show you the result we have reached thus far (branches come in the next chapter).
Part Two : Stem and Branches
Copyright ©2009 by Jan. Images also by copyright holder unless otherwise noted. Opinions expressed are those of the author(s) and not necessarily those of Armorama. All rights reserved. Originally published on: 2003-01-13
Step Three : Making the Bark
Several materials can be used to cover the tree. Several brands of plaster can do the trick. I would not use expensive high quality products like "magic sculpt" or milliput. PU resin is not the best choice either, since it is too runny (and too expensive).
Instead of one piece of twig, you can tie a few of them together first. To do this, you place a few twigs next to each other, as if you would arrange a bouquet of flowers. When you like the result, add a drop of CA glue at the basis where they must be kept together, and wind a string of sewing-thread around that place. The drop of CA glue will make sure the thread stays fixed for the coming 348 years. Next, you cut away everything below the thread with a sharp hobby knife.
When the whole tree is finished, you can add extra drama by spray painting it. This too is a time-consuming process, but it works wonders. Start by painting the whole tree dark grey (almost black) or very dark brown, depending on the result you want. Then start adding more spray paint colour as you go along. Look at trees in your garden or in nature to see how nature "paints" its trees in summer, winter, fall,... Not just the leaves, but also the stem and branches. A coating with dark green (the one-celled moss that covers most tree stems) looks convincing, too. Make sure you mix your colours right before you add them to the tree.