oak before ash we're in for a splash
ash before oak we're in for a soak
Aha - I've made one up
at the same time
and it will be fine
I'm not promising however because I just saw that the Woodland Trust say the oak has definitely arrived first, in fact apparently ash has only made it to first place 4 times in the last 44 years. Warmer springs give the oak a boost so we're destined for plenty of splashing around in that case!