What you need is to replace the coir with 1/16-1/8" size pine or fir bark chips, mulch, or whatever they call it there - much better for all your trees. I would check the label of slow release fert. for info. on your question, and/or if there's an 800 # there (often is one) you could ask them, or else just don't use it - much better to have the control of regular stuff.

Hi Lucy, out of curiosity, what is it about coir that is so bad? I know for the succulents, it was highly recommended to me as you have to let them dry more between waterings and the coir rewets much more easily. I am just curious about what the negative effects of the coir are so as to warn people in the cactus and succulent forum and other friends of mine who've suggested it. I only have my organic matter at about 20% of my soil mix. The rest is high fired clay and 1/8" gravel. It drains quite well. I was using pine barch fines before, but found when I let the succulents dry more, it was VERY difficult to get the water to absorb. It would hit the surface of the soil and just run off (no matter how slowly I went). I don't have a rosehead watering can but rather a plastic rosehead that is attachable to a soda bottle of any size. The water comes out very gently so I don't think that is the problem. Any info you have on coir would be greatly appreciated.

The problem you're having with water run-off is 99% likely due to peat in the soil (it's the main ingredient in potting soils) and it's really hard to 'wet' initially, but once it's wet, it takes forever to dry and therefore unless it's only a tiny component in a grittier mix, ends up rotting roots, as people see the top surface is dry and keep watering (seeing the water run off the top), only the rest of the soil is still sodden. That's the culprit in so many mixes. As far as coir goes, there were some extensive discussions about it on various sites, and while I would have to search now to find the arguments, my definite impression was that it was not an improvement, but had some negative (or maybe at best useless) qualities. Pine bark shouldn't be used in 'fines' but in larger bits, and does act as a great organic (and acidic) component to most bonsai mixes. Nothing should be 'fine' in bonsai anyway, as it'll compact and keep roots from being able to access water properly (like peat). Your succulents could be in almost all grit, with some perlite for weight balance, and only a little coarse soil mixed in - fast drainage is a keystone of bonsai (and should be for most plants), so no matter how often you water (if it's very hot out, or you just like to baby your trees - big mistake usually - the water runs through, carrying needed 02 and washing out old chems and salts. SO much of what's sold as 'Cactus' soil is 99% peat with a very little bit of too-fine sand thrown in, but is mostly crap as far as I'm concerned.

I totally agree about the cactus soil. That was how the coir came up in the first place for me. Pine bark "fines" are the size you are talking about. I think the "fines" part refers to "finely chopped" compared to regular mulch size or chip size. I actually buy it in the form of soil conditioner. I sift out the smaller bits and dust that might be in the bag and so end up with pieces no smaller than 1/8". Any huge pieces I take out. I will do some more research on the coir. I have checked it with my water meter in other plants whose roots won't be so disturbed as my bonsai, and it doesn't seem to be sitting in water. The soil is draining well and pretty evenly moist. I will do some more research to find out the negatives and if you find something, please repost. I know one of the benefits that I read about was that it breaks down far more slowly than peat or pine bark chips the size I need.

As far as the fertilizer goes, I know how the slow release fertilizers work, I just didn't know if it gets used up faster with more frequent waterings that we do for bonsai. I was hoping someone here might have experience with it. I know I've read several post where people incorporate it into their mixes. Thank you so much for your ideas.
Tanya

Tanya,
Re slow release fertilizers, here's my two cents' worth: Two years ago a nursery man told me to use a 12-6-6 granular plant food for the little maple I was buying as well as for my other trees, all of them tropical. It is called Sta-Green Nursery Special. I'm sure it's a fine product for young landscape trees being freshly put in the ground; however, I have seen no difference in the growth or health of my bonsais. One or two may even have had a setback which is probably my own fault because I don't know how long these granules are effective or when and how to replace them. Consequently, my feeding schedule was hit-and-miss and I sometimes poured on liquid food "just to be sure". Hardly a professional attitude. Now I'm going back to regular liquid feeding as I transplant all my trees.
Does this help with your question?
Lucy: can you offer some advice?
Krys

Not very useful, I'm afraid. I'm just not aware of many bonsai people using slow release stuff because we like to be in day to day charge (ha!) of our trees and I think something put in for a long term fix makes that difficult. In other words we see trees changing as conditions change, whether seasonal and weather related, or if indoors, then dependent on soil mixes and light, humidity, etc., and like to be able to respond to changes appropriately without having to account for some long ago applied thing still in the soil in a difficult to gauge amount. I would use it, if I thought it was a good product, on outdoor trees perhaps.

Lucy, what do you use to fertilize? The stuff I am using is supposed to be 3 months, but I think it will be used up sooner b/c of more frequent watering. If I start a regular schedule of feeding, I'd like to know what to use. I guess you may use different things on different trees, but anything would help at this point. I have no places near me that specialize in bonsai. It is difficult to even find places that carry the potss so I generally have to go on-line. That's strange for such a big city, but I've even looked in the phone book and on-line for a specialty store. I found one place that has pots and a few books but nothing else. The fertilizer would have to be something I could order on line or buy at a local garden center.

Good coir is hard to come by. 98% of the coir purchased in the US is obtained as by-product of the bruch and rope making industry in India and Sri Lanka. To make the fibers tough the husks are soaked in salt water. The salts are left in the coir dust that are packed and sold are alternative to peat. In the past there was no market for this waste and it sat in dump and got rained on. This leached the dust and made it a fine growing medium. However nowadays all the old dumps have been used up amd the new dust is not being given time to have the salt leached out before being shipped. So some product come with high ECs an low pHs.
Pls go to my website at www.densuventures.com and click on the research tab.
Let me know it I may be able of further help to you.
Jake

I bought this stuff a year and a half ago. Everything I put in it seems to be doing fine. They are all things that would normally be okay with higher salt contents anyway (schefflera, ficus..) not that salt is good for plants, i know. The coir i used only makes up about 20% of my mix. The rest is fish tank gravel (unpainted and rinsed), high fired clay (rinsed), and perlite. It's been three weeks and nothing is dying. It might be too early to tell. I am just watching them closely. Before I pot up my succulents/cactii outside, I may take each batch in a strainer and try to leach out the salt. Would this work. I will say my soil stays more evenly moist for a longer time and is much easier to rewet (especially on my jade bonsais) so I like that factor.

Tanya - in the end, if something is working for you, keep doing it (or at least don't not do it because it may seem unconventional to someone else). You're obviously doing a lot right, and that counts for a lot more!