Frost has never been known to catch the cockle or blackberry in bloom.
Fennel.
When fennel blooms, frost follows.
Fall Apples.
If the fall apples are one-sided, with thick, rough skins, a severe winter may be expected.
Grasses.
Grasses of all kinds are loaded with seeds before a severe winter.
Goat’s-beard.
When goat’s-beard closes its petals at midday, expect rain.
Hay.