Borago has a very long blooming season and is loved by the bees. It is known for the bees to ignore Clover if there is a substantial amount of Borage in the locality. I will be planting lots of it from next year on.
According to a German study (Maurizio & Grafl) Borago can give 59-211 kg of honey per Hectare, 200 kg according to a Belgium study (Janssens et al.) and 360-400 kg per hectare according to a Russian study (Pel'menev et al.). Since Borago is sensitive to drought we can assume that bees get less honey if the soil is dry and more if its wet, hence these huge differences in studies mentioned above I suppose.
Note the light greenish-creamy yellow pollen.In the Norwegian book "The big bee plant book for beekeepers" they write that Borago is a very rich plant in both nectar (3 starts out of 3) and pollen (2 starts out of 3).
The nectar has 19-54% sugar.