Yellow channel? (Which may be the same as a blue filter, I'm not sure.)
I used the channel mixer and checked the mono box. I then adjusted the green channel to lighten the leaves and stems. Next I adjusted the blue channel to get the flowers the tone I wanted. After that I adjusted it in levels just a little to cover as much of the tonal range as I could.
Awesome picture, m'dear. I enjoy the color changes when you adjust in Photoshop. Most excellent.