bonsaiTALK Community - View Single Post - Soil Stratification-applications to bonsai

I use both methods and have always viewed the bottom layer as a barrier to waterlogging. It accomplishes two things in my book:

1) any irregularities in the pot's bottom that could "pool" water are lower than the rootball and the coarse rock adds to aeration and evaporation of stagnant water.

2) the coarse rock will not easily support the growth of new roots (although some will be there) and keeps them from waterlogging and rotting (which will eventually lead up to the rest of the rootball).

Drainage and aeration are critical needs to bonsai. Since we should be watering frequently, a heavily moisture laden layer of bottom soil serves no useful purpose. With aeration available at both the bottom and top of the soil surface, we can expect a more consistent soil moisture and adapt our watering techniques, as needed.

I feel this will work for any species, but I tend to use it for less-thirsty species like pines and junipers more than any other. I also find I use it more on large trees rather than small ones. On the small and medium size trees, say to 24", I just tend to use straight mix. Coarser for trees I want to have produce more growth and finer particles for trees that are established and/or on the smaller side.

If you have no idea what particle size does in regards to moisture here is a quick way to explain it in your kitchen. If you have an ice dispenser that puts out both cubed and crushed ice. Fill two identical size glasses with both kinds of ice. Just fill them equally to the top. Now fill both with COLD water to the top. Immediately (hey this is ice we're talking about), strain the water out of both glasses into two equally sized containers. Without fail you will have more "water" in the glass with the larger cubes. Simple physics. There are more areas of open space, because there are less sides of particles to form together.

Now the other side of this is that although there is more initial room for moisture, in a bonsai pot coarser soil will provide quicker drainage and less moisture-retention if the material is not capable of absorption. These are much more important factors to consider in soil selection.

I hope we can all find a happy medium (pun intended).

John

18-Mar-2005	#20
John Dixon Air Assault All The Way. Join Date: Mar-2004 Location: Huntersville, NC (near Charlotte) Country: USA USDA Zone: 7-8 AHS Heat Zone: 7 Posts: 1,702	I use both methods and have always viewed the bottom layer as a barrier to waterlogging. It accomplishes two things in my book: 1) any irregularities in the pot's bottom that could "pool" water are lower than the rootball and the coarse rock adds to aeration and evaporation of stagnant water. 2) the coarse rock will not easily support the growth of new roots (although some will be there) and keeps them from waterlogging and rotting (which will eventually lead up to the rest of the rootball). Drainage and aeration are critical needs to bonsai. Since we should be watering frequently, a heavily moisture laden layer of bottom soil serves no useful purpose. With aeration available at both the bottom and top of the soil surface, we can expect a more consistent soil moisture and adapt our watering techniques, as needed. I feel this will work for any species, but I tend to use it for less-thirsty species like pines and junipers more than any other. I also find I use it more on large trees rather than small ones. On the small and medium size trees, say to 24", I just tend to use straight mix. Coarser for trees I want to have produce more growth and finer particles for trees that are established and/or on the smaller side. If you have no idea what particle size does in regards to moisture here is a quick way to explain it in your kitchen. If you have an ice dispenser that puts out both cubed and crushed ice. Fill two identical size glasses with both kinds of ice. Just fill them equally to the top. Now fill both with COLD water to the top. Immediately (hey this is ice we're talking about), strain the water out of both glasses into two equally sized containers. Without fail you will have more "water" in the glass with the larger cubes. Simple physics. There are more areas of open space, because there are less sides of particles to form together. Now the other side of this is that although there is more initial room for moisture, in a bonsai pot coarser soil will provide quicker drainage and less moisture-retention if the material is not capable of absorption. These are much more important factors to consider in soil selection. I hope we can all find a happy medium (pun intended). John __________________ John Dixon Si vis pacem parabellum Stay off the trails of others, that's where the booby-traps are.