Some 20-25 years ago, I bought a 5 lb bag of zinc sulfate. It was
packed by Bandini, which is no longer in business. I use only a little,
on my four dwarf citrus and on my gardenia. Now that the bag is almost
empty, none of the nurseries around me carry it.

Does anyone know of a retail source of zinc sulfate in relatively small
packages? No, I don't want it mixed with iron or boron. And I'm
looking for it in the form of dry powder or granules.

It seems that, in recent years, it's becoming harder and harder to find
single-nutrient fertilizers. All I see are combinations. However, even
the combinations are incomplete. For example, most commercial citrus
fertilizers contain no zinc although citrus is well-know to require
extra zinc. One commercial citrus food contains 0.02% zinc; 0.50% or
even 1.00% would be better.

--
David E. Ross
Climate: California Mediterranean
Sunset Zone: 21 -- interior Santa Monica Mountains with some ocean
influence (USDA 10a, very close to Sunset Zone 19)
Gardening diary at http://www.rossde.com/garden/diary