On 25 Jun 08, at 14:30, Mark Mazer wrote, quoting Jane McGary: > >I grow hundreds of bulbous species that come from areas with > >alkaline soil, and I grow them in a slightly acidic but very well drained > >medium. I've rarely bothered to add lime to my growing mix. > > I am now adding small amounts of lime to all potting mixes. I think that the > warmer and higher humidity of North Carolina makes this necessary in contrast to > the cooler and dryer growing conditions previously encountered in Connecticut. > From temperate to tropical, add more lime to the mix. A package of good, reasonably wide-range pH testing paper is a worthy purchase for the serious gardener, esp. if you grow a lot of things in pots. My potting mix is based on material dredged from an old lake bottom that has a pH around 4.0. You'd be suprised how much lime I have to add to get the pH up to near-neutral 6.5. [Horticultural neutrality is pH 6.5 by convention; not the same as chemical neutrality.] -- Rodger Whitlock Victoria, British Columbia, Canada Maritime Zone 8, a cool Mediterranean climate on beautiful Vancouver Island