soil problem

aesir22

hey all. i bought a chinese elm just over a month ago. i was checking the pot on it a couple of days ago to make sure it didnt need root pruning. it didnt, but there wasnt much soil in the dish. so, i added appropriate compost to it - a layer at the bottom, and a layer at the top as i had been advised.

when i water it now, though, the water doesnt drip through the holes in the bottom. it soaks through the upper layer of new compost ok, but i think the middle layer, the old stuff it came in, doesnt drain properly.

i dont want the roots to rot, and i dont want to overwater trying to get water through the holes in the bottom, but on the same note i dont want to dry it out through fear that water isnt draining properly. any suggestions as to what i could do?

thanks all!

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soltan

Soil drainage problems can be very decieving.
To add soil as you have can, and seems to have caused trouble.

I don't know what season you guys are in there but I believe it is comming up to spring wich should be the perfect time to repot and rootprune.

I would not be concerned that the tree is not root bound if the soil medium is not going to do the job then replace it totally with good stuff. Having two different soil mediums in the pot can work if you are carefull but replacing all the soil is the best way to go.

If it is not the time to repot. Then I woulkd think that if the tree has been doing well in a small amount of soil this will still be fine until it is the correct time to repot.
Messing with it will only give you trouble with little possible benifit.

If the original soil is all that bad maybe a repot out of season is appropriate but I believe we can deal with bad soil until the time is right.
Adding soil top and bottom of bad soil will only agravate the problem.

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eeiko321

well the most BASIC ingredients of soil for bonsai

is 60% Organic & 40% Grit

but since your in england...apparently it rains alot there...
and its cold

you may need to add more % of grit instead....because soil retains water.


im guessing that you dont need a root prune but to just change the soil..

thats what i would do anyways.......

treebeard55

Soil problems can not just be deceiving, they can be fatal.

Depending on where you got it, the original soil may be good, or it may be fit only to be scattered with someone's ashes. In this country, at least, there's a wide range in soil quality when you buy a tree from any place but a bonsai nursery.

It sounds to me as if the layer you added may be too fine. That impedes drainage in a pot. (I can give you the basic soil science if you want; for now, I'll just say that drainage characteristics change when soil -- any soil -- is in a container -- any container.)

Unless I'm mighty much mistaken, you're into early spring now in the UK. It might actually be a good time to repot the tree, rather than leave it in poorly-draining soil. Chinese elm is known for being tough and forgiving. Just be sure to give it a month of extra TLC afterward.

If you do decide to repot, a mix of 70% good compost and 30% grit will work. Be sure to screen the ingredients first, thru a 1/16-inch mesh. (Here in the US, at least, ordinary window screen works fine.) Use only what won't go thru the screen. The rest can safely be tossed onto a garden bed.

One other strong suggestion: find a good local club and take your tree there. Experienced people there will be your best source of information and hands-on help.

Chao!

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chrispr

Cat Litter

http://www.bonsai4me.com/Basics/Basicscatlitter.htm

You may need to buy a few different bags before you get the right one. It needs to be freshwater Diatomaceous Earth, but they never put that on the outside of the bag. I found some in big yellow plastic sacks in my local pet shop. Doesn't break down in water, very absorbant. I am also trying hydroponic "eggs" (approx 16mm dia), roughly crushed by putting them in a bag and jumping up and down on them then sieve the results to get rid of fines. This is also promising as it created very sharp edges. I also have a test plant in Cat-San litter. I am not sure what this is made of, it isn't DE but it is very hard and doesn't break down in water. The granules are bright white and about 5mm dia.

ElGringo

Tesco's lightweight cat litter. I've found it sometimes comes slightly scented, and has a lot of dust. If you use it, make sure you wash it really well before you plant your tree in it.

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Richard

aesir22

how much should i use in the compost? rather strange, but as luck has it im going to tesco's later tonight, so i'll pick some up!!!

ElGringo

Eeiko reckons 40%, thats probably about right for a broadleaved tree like yours. Conifers for example, which generally like more drainage, might need say 60-70% grit.

If you are going to mix organic i.e. bark, compost with inorganic components like grit, just make sure all the particles are the same size. If say, you used a mixture of different sized particles, then the smaller particles would infiltrate the spaces between the larger particles, and 'clog' it up so to speak, reducing drainage.

If all the particles are the same size, then they just sit on top of each other in the pot, leaving air spaces between them, and good drainage and soil aeriation is maintained.

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Richard

aesir22

what is the best way to remove existing soil? is it best to repot while the existing compost is dry, or when it is wet? i dont want to damagw the roots, if its dry wont it be clumped?