Dear Mark: I think there is a very simple explanation. The sap in the cells becomes, for want of a better term, 'thick' and unable to travel inside the plant. There is a certain amount of moisture loss, and as a consequence, the cells loose their turgidity. No damage occurs to the cells, and then, when warmed a little, they regain full turgidity, the sap flows and they are upright again, as you have seen. I am willing to bet that any of the plants, protected perhaps by overhanging branches, are not as affected. I am willing to bet that, if you gave the plants a spray of water, just from the hose, they would also regain their turgidity, but at a faster rate. Cheers, John E. Bryan Mark Smyth wrote: > > hi all > > I have been asked a very good question and don't know the answer even though I see it happen every year. > > After a night of hard frost Narcissus, Galanthus, Tulipa and many other winter and spring flowering plants collapse. As the weather warms up the flowers and leaves come back to life. Why does this happen? > > Mark > N Ireland > _______________________________________________ > pbs mailing list > pbs@lists.ibiblio.org > http://www.pacificbulbsociety.org/list.php