When to see catkins
Many catkins appear over winter and are easy to spot on the otherwise bare branches. They tend to flower during spring, but it depends on the weather. You can expect to see catkins in flower in the following months:
- Hazel: January to March
- Alder: February to March
- Silver birch: March to May
- Oak: April to May
- White willow: April to May.
Recording our seasons
Catkins flowering is one of 69 wildlife events our amazing volunteers record for Nature’s Calendar. This project tracks the effects of weather and climate change on wildlife across the UK – its records date all the way back to 1736!
We ask our recorders across the UK to keep an eye on catkins on their local hazel, silver birch and pedunculate oak trees. We want to know when they appear to swell and release pollen – this is their first flowering date. Though our table shows typical opening periods, these can fluctuate and any changes in their timing may be linked with climate change. That’s why it’s important that we monitor events like this.
By taking a few minutes to share what you see, you'll be adding to hundreds of years' worth of important data for studies worldwide. Every record is crucial and valuable. The data recorded helps us to understand the effects of climate change and other patterns in the natural environment. We couldn't do this work without you!