First flowering
Record hawthorn first flowering when the petals of the first individual flower in a cluster are open sufficiently for you to see inside the flower.
If you have recorded hawthorn events before, continue to record on the same shrub.
Expected Date Range: early April to late May
Available historic data: we have some records from 1753-1810, and 1818-1890. We have very good data from 1891-1947 (9015 records) and some data from 1974-1999.