At 09:15 PM 13/10/2007, you wrote: >Hello: >The reference are only for reference, the environment >maybe more constant than some place. Just as somewhere >will over 40 degree C at day in summer, but also will >cool down to 10 C at night in summer. Fierycloud and Jim, Just to follow on with this from our experience here..... the old established clumps that do best of Nerine bowdenii here tend to have the bulbs sitting at or on the surface, forced there by the overcrowding of the clump. This means that they do tend to lose the insulation factor of the soil temps below ground. When we're getting our temps up to 40'C in the middle of summer we rarely get below 18'C at night (and then only briefly before dawn), and for some periods we can be 20 to 25'C at night for quite some time. I'm mentioning this to act as extra information for Jim to use when working out for his conditions. Certainly we don't get cold nights to 10'C in the middle of our summer (oh but it would be SO nice <grin>), unless we get a cold front move through briefly. I would be expecting the surface soil temperature to probably be higher than the air temperature as well. Jim, take heart!! Cheers. Paul T. Canberra, Australia - USDA Zone Equivalent approx. 8/9 Growing an eclectic collection of plants from all over the world including Aroids, Crocus, Cyclamen, Erythroniums, Fritillarias, Galanthus, Irises, Trilliums (to name but a few) and just about anything else that doesn't move!!