How to go about slabs?

[Sansokuu]

I have to say, slab plantings are one of my favorites if not favorite.

They just look beautifully natural with the way the soil and moss is mounded, and the meandering profiles and informal boundaries. As a potter I would love to make slabs, but as a person who has no idea how bonsai are composed and grown on a slab I don’t know what the parameters are.

Do people make slabs for the planting or do you cater the planting to a slab you like? What sizes and shapes do you look for? Should the slab have flat edges or curved ones? Should I hide feet under there so technically the slab is floating a bit so water can drain? Should the surface be rough, smooth, unglazed or glazed? Throw me some ideas.

 

[Empty Mountain]

Essential Guide to Bonsai Slabs

This blog post by Adam Jones is a good place to start.

 

[19Mateo83]

I have to say, slab plantings are one of my favorites if not favorite.

They just look beautifully natural with the way the soil and moss is mounded, and the meandering profiles and informal boundaries. As a potter I would love to make slabs, but as a person who has no idea how bonsai are composed and grown on a slab I don’t know what the parameters are.

Do people make slabs for the planting or do you cater the planting to a slab you like? What sizes and shapes do you look for? Should the slab have flat edges or curved ones? Should I hide feet under there so technically the slab is floating a bit so water can drain? Should the surface be rough, smooth, unglazed or glazed? Throw me some ideas.

I made one on what I assumed would make a good slab…. Then I sat through a slab workshop and hearing the presenter speak about how the rock itself holds moisture for the tree to use and also having to completely soak the slab periodically to replenish said moisture, I realized my ceramic slab would make for a very difficult to keep wet planting. The design sounded good in my head when I made it though. I’m sure if you could do a little thicker slab and glaze the underside to help seal in the moisture it would probably work out a little better.

 

[rockm]

Slabs can be varied in their appearance, I think. I've got one from Ron Lang that is a simple, slightly concave rectangle, iron oxide glaze and rough clay. It's not a "natural" shape like a stone, but it still works visually. It's pretty large, 24" by 18" and about a 1/4 " thick. I has a central drainage hole in the center. There are no feet, so it has to rest on slats to allow drainage from the central hole.

I also have slabs made to look like flat stones with natural looking worn edges. They have no drainage holes and no feet.

Drainage holes aren't really necessary, but they can help. Trees grow equally well on slabs without them from what I've seen.

One thing I have noticed is that many potters don't make slabs nearly big enough for most uses. Many are also too thick.

Slabs are very effective at conveying expansive landscapes, either for forests, or large rugged individual trees. That landscape vibe is enhanced when there is considerable negative space available around the planting. So, IMO, bigger is better even for smaller trees, allowing the trees to "breathe" visually, with negative space extending beyond the branches. Thinner is often better as overly thick slabs can be distracting. I get ceramic slabs because large flat stones that are appropriate for bonsai are not common and can be expensive. Joe Day in Alabama was/is famous for working big flagstones into bonsai slabs. He pounded and chipped edges on large stones then worked them with a power grinder to make them looks weathered.

This planting by Mas Moriguchi is on a man-made slab if I'm not mistaken (and I may be). Even if it's not, this is very nice example of how a slab should work. It's large.

 

[Fidur]

I very recently used a slab for a forest. But it was not sold with that purpose. It's a garden walking stone I found in my garden center. They are not expensive (15$) and either heavy (I can move it alone). So, have an open mind in your search...



Edit: They have no drainage or wiring holes, but as I've discovered myself, those are not needed....

 

[johng]

For me there is little substitute for the real thing when it comes to slabs... IMHO ceramic slabs need to be made to look as much like stone as possible. Given that slabs generally are planted with an open area in one direction or the other they need to be larger than a bonsai container for a similar sized planting. To my eye, thin edges are a must. Perhaps the biggest advantage of ceramic slabs would be premade tie down holes. Drainage is not necessary unless the slab is very concave and will hold a fair amount of water.