The First and Last Rose of Summer

Burnet rose Rosa pimpinellifolia is the most fragrant of all the British wild roses and also the first to come into bloom - sometimes in mid-May - and now it has come back into bloom in a hedgerow here at Wolsingham in Weardale.

There's been a lot in the press recently about the heat-wave inducing spring flowers to produce a repeat performance in October but it's not really that uncommon. Primroses, for example, quite often produce a few flowers in early autumn. For any species whose flowering is triggered by daylength, the hours of daylight are more-or-less similar now to those that the plant would have experienced in spring, so it's just responding weakly to the environmental stimulus that switches it into flowering mode. Spring-blooming wild flowers are more likely to produce an autumn encore if they experience in growth check in summer - maybe drought or low temperatures - that's followed by favourable conditions that allow resumption of rapid growth in late summer. I've noticed this particularly in some trees after a summer drought - somewhere I have some photos of rowans producing flowers alongside ripening berries in late summer, when rain after a drought has triggered a resumption in growth.