You've heard about air pockets or maybe you haven't. But what exactly are people referring to when they mention air pockets in the soil?

Air pockets are simply sections of air where the soil has not filled in around the roots. Typically they are formed due to clumping in the soil and not falling into place correctly in a bonsai pot. Sometimes roots can also block out soil from reaching other areas of the pot.

The danger in having air pockets in your soil is that the roots will dry out at that location. Without soil coming in contact with the roots, the roots will dry out easily which may cause the tree to die.

The most common spot for air pockets is directly beneath the root ball. Usually this is caused by not putting an adequate layer of soil or hill on the bottom layer of the pot. If you don't do this, the roots will push the soil away from the bottom of the tree outwards and create an air pocket.

So how do you prevent air pockets? The solution is very easy. Simply use a repotting stick to check for the location of air pockets. Insert the stick in various points of the soil and shake to see if the soil falls in more. If it does, keep shaking the stick to fill the air pocket with soil.