Soil amendments

Mary Sue Ittner
Wed, 04 Sep 2002 17:08:44 PDT
Dear Jane,

I agree with Diana about the mushroom compost. I used to use it in my 
vegetable beds and one year was out of other things and used it with a 
couple of pots of bulbs with disastrous results. Someone said it was the 
high salts. Regardless I haven't used any since.

We get a lot more rain in our area than the one you described, but I have 
used a mix of 1/2 regular compost and 1/2 quarter minus fir bark to improve 
our basic sandstone, decomposed and still solid soil. A nursery man here 
who is a soils expert recommended it to mix with my soil before planting as 
he thought it would take longer to break down than some of the other 
suggestions I had. What they sell as top soil here I would define as silt. 
I think it has worked pretty well in the beds where I used it. Those beds 
weren't specifically for bulbs although there are some bulbs in them that 
are growing well.

I'm not sure I understand why you think Mediterranean bulbs would be 
unhappy with composted wood products. I remember when Will Ashburner was 
here he thought some of the fir bark I had would be good to use to help 
create air filled porosity. He was giving the potting mixes available low 
marks compared to Australian standards and looking at what I had available. 
And he knew I was growing mostly Medit. bulbs. I found his quote from my 
IBS archives about what he used for a potting mix and he grew lots of Medit 

"I have great success growing bulbs in a soil less potting media, made up 
of 80% different grades of shredded pine bark and 20% coco peat (shredded 
coconut husks).  The latter was previously coarse river sand but was 
substituted to make a lighter (to lift mix).  The mix has an air filled 
porosity of 15%.  This is the key I believe, not so much the materials used 
but the physical characteristics of the mix."

Randy Holbert lives in the area you are talking about and grows bulbs, but 
hasn't joined this list yet. I'll forward your question to him and see if 
he comes up with any things that worked for him.

Mary Sue 

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