I have an oriental poppy 'Patty's Plum' growing in new potting compost in a pot with good drainage. It sits in full sun, and I water it as needed in the recent dry weather. I purchased it from a nursery in May so this is the first season I've had it. Its lower leaves look healthy and for the past couple of weeks, the first two flowering stems have been growing and have felt quite sturdy. Yesterday, I noticed that the younger of the flowering stems has developed a weak spot that is dark brown in color, and the stem is now bent at 90 degrees (see photo). The leaves on the flowering stems also look slightly blackened at the edges (see photo). My location is the south-west UK.
Could this weakening be due to water sitting on the stem overnight and causing some tissue rot, or is there another likely another cause (can wind cause this)?