I suddenly realised that about 5 days ago none of the flowers on these two Hypericum x hidcoteense ‘Hidcote’ were out, but all were in bud. Then about 3 days ago they were all out.

The plants came from the same nursery at the same time, and if they’re what they said they were they’re clones, and are genetically identical. But still, how did the plants behave identically when they’re a few meters apart?

It’s surprising enough when all the flowers on a single plant come out at the same time, but at least one can suspect chemical signals flowing through the stems.

It can’t all be down to temperature, day length etc., which are obviously the same for the two plants, can it?

Or is it chemicals in the air, which could trigger flowering on one plant or several close together.

Someone must know the answer.

The other question, of course is – Why? If you want to be fertilised by another plant why open all your flowers together? I suppose if you’ve got male and female bits on the same plant then you arrrange for all your flowers to come out at the same time, and for the female bits to be receptive at a different time from the male bits. But then you need different plants to fower at different times.

Can anyone tell me what’s going on?