Gone Blue: Colour-Changing Flowers

Last month I photographed these tiny spring pea (Lathyrus vernus) flowers. After I had finished photographing them I noticed that they were still changing colour after they had been picked.

The flowers had started off as a purple-pink but were changing to blue as they aged. I wondered if they would turn entirely blue and I found, after a couple of days, that almost all of them had. (As you can see, there is one flower that has stubbornly managed to remain pink in the top photograph. However, I reckon it would have turned blue too if it had been able to last long enough.)

Having flowers that change colour is a bonus for a photographer, allowing a whole new set of photographs to be made of the same subject. It’s also fascinating to watch as this happens.

Apparently the reasons for this kind of colour change are practical. It lets pollinating insects know that the individual flower has already been pollinated and will now have little pollen or nectar left to offer them. This helps the plant by directing the attention of pollinators to those other flowers that are still waiting to be pollinated.

Colour change happens in other plants too. The one that I’m most aware of at the moment is Salvia ‘Hot Lips’. That’s because I bought what I thought was an un-labelled sage with a good bright red flower which would be ideal for an area of planting with hot colours. (I already had the magenta-flowered Salvia microphylla, which flowers really well here. This looked like a red version of it.)

I was a bit surprised later on, when the new flowers on the plant began opening in the well-known red and white bicolours of Hot Lips. From what I’ve read, the flowers on this plant can be red, bicoloured, or white, depending on temperature or growing conditions. So it’s an interesting plant to watch but not so useful if you have a particular colour scheme in mind!

Colour change isn’t something I’ve been much aware of in the past. But now it has me intrigued and I can see that it may give me good photographic opportunities too. So I’ll be keeping an eye open for other plants that do this…there’s always something interesting happening in gardens!

You can see my post with the spring peas still in their original pinks and purples here.

Lathyrus vernus (spring pea) flowers