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How do flowers know when to bloom?
CrowdScience
Sep 24, 2021

This year has been a weird one for UK gardeners – unpredictable spring temperatures meant flowers failed to bloom and throughout the rainy summer, slugs have been savaging salad crops. But why and when plants blossom is about more than just early cold spells and wet weather, and a listener in California has asked Crowdscience to investigate.

Flowering is vital to both plants and us. Without it, they wouldn’t be able to evolve and survive (and we wouldn’t have anything to eat). Anand Jagatia hears that different species have developed different strategies for doing this based on all sorts of things, from where they’re located to how big they are to what kind of insects are around to pollinate them. The famously stinky Titan Arum, or corpse flower, for example, blooms for a single day once every decade or so before collapsing on itself and becoming dormant again.

This gives it the best chance of attracting carrion beetles in the steamy Sumatran jungle. But other plants open their petals much more regularly, which is a process regulated by a clever internal clock that can sense daylight and night. It’s even possible to trick some of them into producing flowers out of season. Cold is also a vital step for some brassicas and trees, and scientists are starting to understand the genes involved. But as climate change makes winters in parts of the world warmer and shorter, there are worrying knock on effects for our food supply.

Produced by Marijke Peters for BBC World Service.

Featuring:

Guy Barter, RHS Professor Judy Jernstedt, UC Davis Professor Dame Caroline Dean, John Innes Centre Professor Ove Nilsson, Umea Plant Science Centre

(Photo credit: Getty Images)

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How do flowers know when to bloom?

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