9:54pm So the yellow iris buds have opened and they are not so much yellow as a light orange with a bright orange beard, actually very pretty and I would be very pleased if it were not part of an established clump. I googled to see if there was any explanation for this change of colour in two clumps of dark mahogany irises but not in the third clump at the other end of the bed. First of all there were several blogs saying categorically, No but definitely no, irises do not change colour… well maybe if they got hit by Round-up. However there were plenty of examples of irises changing colour without the assistance of Round-up. Eventually there were a couple of acknowledgements that Bearded Irises do change colour (along with Glads and Tulips).
One reason can be stress which causes production of certain pigments in the flower tissue to be suppressed so that what you see is the underlying colour without the ‘good’ colour that produces a particular shade. Once the stress factor goes away the irises can produce normal flowers again. Stress factors can include an overgrown and starving clump, heat and cold can produce short term effects. Self-sown seedlings are likely to come up a different colour. Then there are true genetic mutations or ‘sports’.
Some of what I suspect is going on is that unstable hybrids are reverting to their strongest genetic parent. I think that is what happened with Best Bet losing its blue colouring to become a more standard purple and at the same time the falls and standards became a bit smaller and lost their frillyness. Comparing photos 2 and 3, I think the same thing is happening here, the colour in 2 is a bit less rich, the flowers are a bit smaller and the falls and standards are much smoother. So is the yellow one a reversion to a parent or a sport?
The last photo is Allium Atropurpureum
Allium Atropurpureum Flowering
Veronica prostrata Trehane Flowering
hilled up again, the soil is nearly to the top of the tub
Alpine strawberry Harvesting
Fragaria vesca spp. alpina
another small handfull