Hazel catkins

, 16 February 2019
Hazel catkins
© Mark Monk-Terry

By Charlotte Owen

WildCall Officer

It may not seem like the best time of year for botanising but there are some unusual flowers in bloom in February.  Alongside the familiar clumps of snowdrops, thousands of yellow hazel catkins are ripening in the winter sunshine.  They are flowers, despite appearances.  A typical flower has showy petals, sometimes with an elaborate pattern, a source of delicious nectar and maybe an alluring scent, and these are all features designed to attract bees and other pollinators.  But the hazel does not rely on insects for pollination, and there aren’t many around this early in the year, so it has no need to attract them.  Instead, the hazel relies on the wind and its flowers are designed accordingly.

The catkins are the male flowers and they produce copious amounts of powdery yellow pollen.  Each catkin actually consists of 240 individual flowers arranged on a dangling stem, and when fully ripe it only takes the slightest touch to release a cloud of microscopic pollen grains.  These can be carried over a great distance on a favourable breeze in the hope of reaching their intended target, a female hazel flower.  Of course, wind dispersal can be a bit haphazard and a lot of the pollen will be wasted, landing on damp branches, sticking to spider webs or dusting unsuspecting birds – but the sheer volume of pollen produced helps improve the odds.

The female flowers are tiny, so you’ll have to look a lot closer to spot them, but every hazel produces both male catkins and female flowers (but cannot pollinate itself).  The female flowers are equally unusual and resemble a scaly green bud with a bundle of delicate red tendrils emerging from the top.  These are the female flower’s styles, or pollen tubes, and any wind-blown pollen grains that land on them will fertilise the flower and trigger the development of a hazelnut. 

Even the name is a bit strange.  Catkin is derived from the Dutch word katteken, which means kitten, since the flowers look like fluffy kitten tails.  They’re also known as lamb’s tails for the same reason, and this name has a stronger association with the onset of spring.

Hazel flower

Leave a comment


  • Dr Leonard Barrett:

    Thank you for that information. I’ve been wondering for years how the hazel tree was pollinated
    especially as the male catkins appear so early in the Autumn with the female flowers so relatively insignificant.

    05 Jan 2023 15:50:00

  • G. Nash:

    I gather that tho catkins should have not yet appeared, climate confusion with all its horribly mixed messages, has certainly impacted on our male catkin bedecked hazel tree.

    07 Jan 2023 09:31:00

  • Tony Brown:

    Just checked out the females on the Hazel outside my static. Amazing.

    18 Feb 2023 12:51:00

  • Sophie McKee:

    Are there other trees/ shrubs which produce both male and female flowers please?
    Thank yoi

    20 Feb 2023 07:21:00

  • Sussex Wildlife Trust:

    Plants that have both male and female flowers in separate structures on the same plant are known as ‘monoecious.’ This quite literally means 'one house.' This contrasts with 'dioecious' plants ('double house') which is where male flowers are on one plant and female flowers on another.

    There are a huge number of examples of each. Most of our common trees are monoecious, so Birches/Oaks/Pines/Spuces... Ironically, almost all of the Willows are actually dioecious.