In coneflowers, I have Echi. Pow Wow Whites, Purple Magnus, and white Magnus from seeds as well as Black Eyed Susans and Sonoma BES. The Bees cover the purple Magnus and are ho-hum about the rest. For any one bee on a white or yellow there will be 5 or 6 on the Purple Magnus....
OK, clearly this is a HINT. I like the yellows and whites and the bees like the purples..... Um, why???
(The picture, just because.)
I have noticed the same thing. My very uneducated guess is that the purple color is more attractive to them OR since the purple ones are closer to the original native coneflower, it is less hybridized and perhaps makes more nectar? On a side note, it seems like the purple ones I have make bigger and more viable seeds than the other colors. I have been able to grow prairie splendor and merlot from seed but the others failed or I could not harvest any seeds at all. No seeds = no pollination or no seed producing ability in the 1st place?
I was thinking it might be the smell, is Magnus fragrant, mine is too small for me to know. :(
I see bees on all the colors. They don't like the doubles though.
