We’ve had all kinds of weather thrown at us in the last two weeks- including several severe frosts. The frosts have seen off most of our Dahlias but we’ve nothing to complain about as some of the plants have been producing flowers continuously for five months. Dahlias are well known for being susceptible to the first frosts, but some of the Dahlias in our garden are made of sterner stuff. These are the species tree Dahlias, which have not only survived the frosts but, in the warm spell of the last few days, have shown vigorous new growth. We have three types of tree dahlias in the garden- Imperialis, Tenuicaulis and Excelsa. All are well over 6 feet in height and the Excelsa and the Tenuicaulis have been flowering for months now. The Imperialis, which is the largest, hasn’t flowered as yet and is unlikely to- in fact it has only flowered outside in this garden once- and that was after the exceptionally hot summer of 2006, when it came into flower on December 6th. Unfortunately it seems that not all species Dahlias are frost resistant- the smaller varieties, such as Coccinea have succumbed, just like the hybrids.