Well-drained growing media (was Oh No! A Boophone disaster!)
Tim Harvey (Sun, 04 Oct 2009 12:00:40 PDT)
Beware of yellow pumice! It can be the result of high levels of boron, which may be phytotoxic.
T
In Washington state, Verkist orchid nursery outside Bellingham sells (or used
to sell) both washed and unwashed pumice, the former in your choice of sizes.
It's been many years since I was there, but the price was quite reasonable. The
pumice they sold was a warm ocher yellow, very attractive.