I've had this rose for a number of years. Each petal is velvety and so dark it looks black from a distance. In your climate I would grow it where it could get some shade from the midday sun. It can burn in the heat. If exhibited the flowers open quickly, but it is hard to beat as an open bloom if it is fresh! This rose gets more comments from visitors than any other rose in my garden.

If you are already treating your other roses for blackspot, then do the same for Black Jade. It doesn't need any additional care except as Tenor_Peggy noted.

I had Black Jade for about 3 years and just recently gave it away, primarily because I found a mini of similar dark red that I like better (Salute), and I have very limited garden space and have to make tough choices. Black Jade has both good and bad qualities. Strengths are its unique deep black/red coloring and excellent form. It's a top show mini. Mine had fair amount of bloom, but not great. It also blows to fully open very fast and burns in our hot sun. I definitely agree with the above advice to give it part shade. Mine did best when I gave it only morning sun. Salute, which I mentioned above, is just a shade lighter and has good form, though not as good as Black Jade. But its a much better garden rose in my experience. If you show minis or plan to, you picked a good one. Black Jade is one of the best red minis for show.