Hello Gianni, We had a discussion on this list on soil temperature in pots. It was sparked by a question why Pancratium maritimum would not flower and the explanation was finally that the bulbs sit so very deep in their native habitat that they are protected from summer heat. And bulbs in pots would become too hot. Maybe the same applies to your Gladiolus. I do not grow it here in Portugal but I had a rather unhappy plant of in in a pot in Germany. Reading the comments of those who grow it in the UK or Ireland and considering its native habitat it may simply become too hot in a pot in Italy. Where in Italy do you garden? Shading the pot by standing it in another bigger pot or using other plants to shade it might help, or sinking it into the ground in a shaded place as cool as possible. But in our mediterranean climates summer heat may be a limiting factor to grow some plants.... There may also be a difference in soil temperature between clay and plastic pots and between white or black plastic pots. In my garden in Portugal there is a marked difference of several degrees between the sune exposed side of the house and the shaded north side. This is the only place where heat sensitive plants will survive in my garden. Hope that helps, Uli _______________________________________________ pbs mailing list pbs@lists.pacificbulbsociety.net http://lists.pacificbulbsociety.net/cgi-bin/…