All 89 bee plants
Michaelmas daisy pollen
Aster spp.
Reddish yellow, in the orange range.
FloweringSeptember to October
PollenGood
NectarYes
SeasonAutumn
WhereGarden
Late garden nectar for the last of the foragers.

Easy to mistake for these
Closest pollen colours in our set, measured the same way the pollen identifier scores a match. Colour alone will not settle it, so check the flowering months and what is actually growing near your hives.
Out at about the same time
Saw a load like this going in?
Sample the colour against all 89 plants, then keep a forage record per hive.