H.B. Parks, in a letter to Frank C. Pellett, author of American Honey Plants, stated that it "makes a wonderful growth and that it is a most remarkable honey plant" (observations made in Texas). However, Vitex agnus-castus, though it blooms profusely, is not much value to bees.
So when it is stated that Vitex agnus is an improved selection of Vitex Negundo is it really? Vitex agnus has been "improved" for larger, showier flowers and there is no doubt that bees do still visit those flowers however their nectar yield is not the same had it been Vitex Negundo.