Moss technique

It’s common, when displaying bonsai at indoor exhibits, to cover the surface of the soil with moss. The alternative – dirt – doesn’t really compare.  Scott decorated his Ponderosa Pine with a great arrangement of mosses and lichens at this year’s BIB exhibit.

Moss on ponderosa pine

Depending on where you live, you may have found that moss doesn’t just show up the week before exhibit. Either that or you find it difficult to keep it under control, a problem I do not have in Northern California. For years now, I’ve taken note of all of the patches of attractive moss I run across that grow on public property. Come January, I go moss-collecting. If all goes well, I end up with a few trays like the one below.

Collected moss

One other ingredient is necessary to make the process a succes – moss. White sphagnum moss, to be specific, the kind usually available from orchid growers. It typically comes in clumps`. Run it through the large screen you use when sifting bonsai soil to produce the fine particles shown below.

White sphagnum moss

With these two special ingredients close by, it’s time to get started. The first step is soji – removing, or “cleaning” the top layer of soil. Depending on the quality of your soil, this step may not be necessary. Because I use organic fertilizers like cottonseed meal, I find that in January the decomposed fertilizer becomes gunky and impedes drainage. Now’s a good time to remove it. I do this with bent-nose tweezers – possibly the most used tool in my bag.

Removing the top layer of soil

If any roots stick out, I clip them with root scissors.

Clipping an exposed root

I then fill the pot with bonsai soil but stop a quarter-inch below the lip. This is to make room for the moss. If your moss is thicker, leave a bigger gap.

Fresh bonsai soil (akadama, lava, pumice and charcoal)

Here’s where the sphagnum moss comes in. Sprinkle a thin layer over the soil.

White sphagnum moss

The sphagnum moss helps keep the dollups of fresh moss moist. Watering it down before placing the fresh moss makes the work easier – and keeps it from blowing away.

Sphagnum moss moistened – ready for fresh moss

This is where the moss work becomes technical. Clipping the base of a dollup of moss helps it fit into the pot.

Preparing a clump of moss

Some folks start in corners – others begin around the base of the trunk.

One down, more to go

It’s possible that somewhere, someone has written a treatise about moss-laying. I like to think so anyway. Turns out it’s much easier to do a bad job than it is to make the moss smooth and attractive. I’ve seen many workshop students shrug their shoulders and breeze through a tree only to find themselves reapplying the moss under Boon’s supervision.

Half-way there – Jeff always does a good job

Where can moss-work go wrong? Some things to keep in mind. Like-sized clumps look good together. Placing large clumps on the left side of the pot and small clumps on the right side stands out something awful. The same rule applies to moss color, character, and direction. Yes, direction. Look closely and you’ll notice that most moss leaves that grow together point the same way.

Some of the most attractive work blends together different kinds of moss. It’s worth experimenting to see what effect you like. Bonus points for good use of lichen. We’ll save antenna-theory for another day.

Freshly applied moss

Tamping the moss with tweezers or trowel helps it stay put. As moss frequently grows in mucky soil, firmly pressing the moss into place really sets the clumps into the sphagnum and bonsai soil below.

Tamping the moss with tweezers

Tamping the moss with a trowel

For a final touch, feel free to sprinkle tiny soil particles over the moss and sweep away the excess. By filling in the gaps, the edges of the clumps don’t dry out so quickly. A popular BIB top-dressing is black lava, or “pepper,” as you’ll hear folks refer to it in Boon’s workshops.  The purple lava works well because it stays fairly dark when dry – pumice and akadama are lighter-colored when dry.

Sweeping away excess “pepper”

Moss-work complete

Once all’s set, water in the moss-work. Bonsai with freshly applied moss can be placed in full-sun, but care must be taken so it doesn’t dry out. The longer between the moss application and the exhibit, the more the clumps will fuse together and the taller the moss will sit in the pot. Some day I’ll lay moss early and let it grow for a month before exhibit. It makes for a somewhat rangy look that complements rough-hewn bonsai well.

Here are a few more examples of moss-work from BIB’s 11th annual exhibit.

Black pine with green moss

Ponderosa pine with moss and lichen

Root over rock procumbens juniper with green moss and a small fern

Gooseberry with green mosses