Hi George, they are pretty easy to make, with no painting or staining required.
I bought 4 or 5 sizes of dowel rods, from 1/4" to 5/8". You want to get them at 1/8" to 1/4" smaller than the largest stump you want to model. I also got a couple of packs of black sculpy, which is a clay that you can bake to cure. There are other brands that work the same. If I wanted the bark to be a color other than black, I would get white sculpy and paint them after the fact. I tried brown sculpy, but didn't like the results.
I cut the dowel a little less than half way through, then turned them over and again cut a little less than half way through. I was not carefull to line up the cuts evenly. Sloppyness add to the realism

Then I snapped them by hand. Smaller dowels were cut too long, so they could extend into a drilled hole in the layout. Larger stumps were cut a little short of the inteded height.
Then, using a beer bottle, I rolled the sculpy out on a sheet of wax paper (after kneading it a little). Then wrap it aroundthe dowel and form roots by hand. I carved deep into the bark with a pick, you could use a small nail or any small pointed object. Then I used a small, toothbrush sized wire brush and made some smaller lines inthe bark.
Bake at 275 for 20 to 30 mins. The instructions indicate much less bake time and warns not to overbake, but it worked better to bake them longer. I guess the dowel removes some of the heat.
Let them cool for 15 or 20 minutes befor eeating, I mean planting on the layout

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