Water run off

[Tona]

Hi all,
This is probably a question that has been answered but I am having some problems with water runoff when watering. I use a pretty free draining mix (1/3 pumice, 1/3 fired clay, 1/6 sifted sand and 1/6 cactus mix). I use a watering wand and take my time watering. I live in Santa Clarita CA which is hot in the summer so I believe a little organic in the mix is good (hence the cactus mix). My problem may just be that I have some of my trees planted too high trying to expose the nebari. So my question is: How much below the rim of a bonsai pot would most of the more advanced members plant the tree?
Tona

 

[Alex DeRuiter]

That depends entirely on how you want the tree to look. As long as it's only the nebari that's above soil, it should be okay.

As for the water runoff, how long has it been since the tree has been repotted? A lot of times if the water isn't immediately-ish absorbed, it means that there's very little room between the roots/substrate for water to flow into. If you dig down a little bit and feel how firm it is, you'll be able to tell whether or not it's root-bound. If it is, just repot it when the season comes (which sounds like around now, if you're in southern CA [**Don't repot if it's not the appropriate time, though. I'm not from that area, so I don't know when you would usually repot/root prune your trees]). Thinning it out will help with water absorbance into the substrate.

Hope this helps.

PS - An article on repotting here. Another good article here.

 

[dick benbow]

As stated there are many reasons to do things differently but as a general rule I like to have about a half inch for the soil to be below the pot rim. Then when the soil gets filled with roots, one look as it appears above the pot rim and the more difficult it is to have water absorbed is my red flag for repot. many times in the spring with a tree that does not need repotting, I'll remove half an inch of soil on the top and put a new fresh layer on which seems to rid the surface of things like weeds and irish moss and last year's fertilizer crust.

My sensae is the curator for the pacific rim bonsai display. he has quit using volcanic rock as drainage as it's hard on his shears used to reduce the root growth during repotting and saves him from constant resharpening. additionally he has begun using charcoal to the tune of about 10% of the total mix. I have followed his mix now for about two years and find that it works for me, that's 1/3 equal parts of pumice, akadama (double red line) and kiru a rounded softer drainage sand/pebble from japan. this year in addition to the charcoal, I've been adding 10% kanuba ( a mainstay for azalea).

 

[rockm]

It sounds to me as though you've potted the root mass too high in the pot, resulting in fast water run off down the sides of the root mass before it can penetrate down into the pot.

That means you're either leaving too much root on the tree, or using a pot that's too small .

Typically I leave a 1/4 to 1/2 and inch of space below the rim of the pot for the soil at the edge of the pot, with the trunk that much, or a little rising above the pot's rim. This acts as a drain of sorts to prevent soil erosion off the surface. Of course, that means the root mass going into the pot has to be thinned out and flat.