Is it knotty to grow black roses? ...
Not any harder than growing most hybrid tea roses. They can be a little picky.
But first you enjoy to find a good plant.
http://www.growquest.com/rose%20black_ba...
That may help you. If you find growing them to be difficult, here are other black flowers, even green (such as Green Wizard Rudbeckia, Bells of Ireland, Hellaborus), you can try. There are black hollyhocks, also.
Answers: Yes, that's why a pure black rose doesn't exist yet.
The closest rose anyone can grow that looks somewhat black is a grey purple-red/maroon or "deep blackberry" colored rose.
"A pure black rose does not exist, however within are some very shadows red roses out there near names similar to; 'Black Baccara', 'Barkarole', 'Black Beauty' and 'Black Magic'."
http://interrose.co.uk/black_roses.shtml
http://www.flowershopnetwork.com/pages/n...
Here's the Black Bacarra Rose: "A ...dark red rose, Black Bacarra conveys a sense of illusion due to its deep blackberry color. When placed lower than dim lights, the Black Bacarra rose appears mysteriously black."
http://www.fiftyflowers.com/product/Blac...
.
Just as here are no blue roses, there are no black ones.
Sorry roughly that.