I saw one of your posts recently, outlining your idea to add a substantial % of cocoa bean hulls to your soil mix & I thought it would probably give you fits.

Different species of microorganisms are predominate during the various temperature phases of composting, which is what is happening to your soil. Addition of the moisture you are adding, and N in fertilizers cause their numbers to skyrocket. Initial decomposition of cellulose rich media is carried out by mesophilic microorganisms, which quickly break down the soluble, readily degradable compounds. The heat they produce causes the soil temperature to rapidly rise. As the your soil temp rises above about 100* F., the mesophilic microorganisms become less predominant and are replaced by others that are thermophilic, or heat-loving, which really eat fast. ;o)

Though conifer bark contains cellulose, it's also rich in lignan and suberin, chains of hydrocarbon molecules that are much more difficult for microorganisms to cleave. Decay and accompanying soil collapse are much, much slower in conifer bark soils than in peat soils or soils based on other organic ingredients.

Normal root function in a high % of plants begins to be impaired at around 80 - 85*, and once soil temperatures hit 90 - 95*, root function would be severely impaired or even stopped.

Al

Al, if I read you correctly, is it the cocoa bean hulls that are the cellulose rich media which are breaking down?

Hopefully I'll get pine bark on Wednesday and everything will be OK again. Home Depot has pine bark fines but they look and smell too fresh. The pine bark I got last year was that Mid America brand and looked exactly like in your picture. This worked out very well.

I was just on the way to share what I found today. I was shopping @ Home Depot for a 24" square paver to use in the garden as a table top to set containers on. I walked bast the bark & mulch & spied something interesting. There was a ripped bag of mulch that looks perfect for container soils. The bag says: "Golden Trophy Pine Bark Mulch". It's bagged by "US Mulch LTD.", in Columbus Ohio. It really was perfect stuff - nicely composted & just a hint of piney smell. I didn't need any more, but I bought a bag anyway - just to be sure it was suitable. When I got it home & inspected closer it appeared that there was very little sapwood in it. I hope you can find it in CHI, Mea. ;o)

Al

Thanks Al! It appears the nursery where I got the Mid America pine bark last year aren't going to have it this year. The Home Depot around me has that Golden Trophy pine bark and I had no other options so I bought 9 bags before I read your response. Now that you recommended it I'm going back today to empty their pallet. :-)

Ironically, the Home Depot by me has the Mid America Cedar mulch. I wonder why they don't carry the Mid America pine bark too. But it doesn't matter. I'm glad to be back in business and able to start planting. Something is very wrong with the cocoa bean container and I have to compost about 6 cubic feet of soil I mixed last weekend.

Oops. I read your message more closely and noticed you didn't completely recommend it. Is the lack of sapwood going to be a problem. I have to go with the Home Depot stuff because no one around me carries pine bark fines and I have to get the containers ready for planting now.

Mea, check with Walmart to see if they carry Greensmix soil conditioner by Waupaca Northwoods, it's what I found in SE Wisconsin and is consists of pine and fir bark in pieces that are 1/4-3/8 inch in size with some composted.

Otherwise you can call them at 800-365-4032 to find the nearest retailer to you.

Mea - the lack of sapwood is a good thing. Sapwood - especially small pieces (sawdust size & slightly larger) break down quickly & cause N immobilization.

The "Golden Trophy Pine Bark Mulch" is definitely about as close to ideal as you'll find. I wouldn't hesitate to use it in my own soils - in fact, I will use it as I mix soils for display containers next week.

Al