Bulb food

Jane McGary janemcgary@earthlink.net
Wed, 21 Oct 2015 10:50:49 PDT
Heather asked," So bulb food? Any suggestions? Is pumice a substitute 
when planting?"

Pumice is not a fertilizer, but it adds some mineral nutrients, 
especially if you can get unwashed pumice including fines (this is hard 
to buy even here, where pumice is sold by the cubic yard). It will raise 
the pH of acidic soils slightly. When mixed with peat or other very 
acidic components, pumice breaks down more quickly than it would 
otherwise, and presumably its minerals then are more available to the 

I use white pumice, but Loren Russell of Corvallis, Oregon, a keen 
grower, swears by red pumice (locally known as scoria), which I think 
has a higher iron content. I haven't seen it in sizes smaller than about 
2 cm, and I prefer the smaller size for seed sowing. My new raised bed 
for bulbs has a larger, washed size of white pumice, but also local 
concrete sand, which has fines of similar mineral content; I also added 
some limestone chips and an organic mix. I do apologize to the 
scientific gardeners, but I make planting beds much as I cook -- to my 
own taste, and using what's available.

Jane McGary
Portland, Oregon, USA

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