I really like this picture and the statement it is making. Interesting composition and contrast. However I don't think it really fits the challenge description and I expect that your score will be hurt.
Pretty picture, and good title. However, the emotional impact, and the story based on the title, is entirely about new growth in color replacing a dead, B&W area. That takes it out of the challenge for me.
I believe the intention of the challenge was to take a b&w photo in color mode. This is why desaturation was discouraged. To make it more challenging. I don't think the challenge was to shoot a color photo with b&W in it. It may be a suttle difference in interpretation.
Otherwise great photo. You placed your plant down in the bottom 1/3 of the screen which is a great place for it. Composition-wise this is a good photo.