The darkest rose color is a very deep red that reads as near black in shade. No rose is truly black, whatever the catalogue promises. Petals can stack pigment until your eye gives up and calls the color black. Move the same flower into direct sun and the red comes right back, which surprises most people the first time you watch the change happen.
I checked my own plant against the clock. The Black Baccara rose beside the garden wall photographed as a plain red flower at noon, flat and unremarkable. By seven that evening the same bloom had gone so dark that you could mistake the flower for a hole punched in the hedge. Same flower, same day, and the only thing that changed was where the sun sat.
Petal color comes from anthocyanins, and those pigments run from red through blue red. That is the whole range you get. Ahmad and colleagues found that these pigments read magenta to reddish purple, and that dense pigment is what your eye calls black. No petal carries a black pigment. A breeder can push a rose darker and darker for decades and still stop at deep red, because no plant in nature comes out purely black.
You probably came here expecting black ink on a stem. That flower does not exist, in roses or anywhere else. The darkest rose color in any garden is a red so saturated that your eye stops reading the color at all. Drop the ink idea and the deep reds get more interesting, because the whole appeal of these roses is the way the color shifts from hour to hour.
Black Baccara is the name you will run into first, and the flower behaves the way the pigment story says. In deep shade the petals go so dark that you lose the edges. In flat evening light the bloom holds that black look and the velvet surface shows. Put the same flower under strong midday sun and you get burgundy, or a muddy brown on a harsh day.
Where you plant your rose decides how often you get the effect. A bed that bakes from ten in the morning until four in the afternoon hands you burgundy for most of the day. Grow that same plant on the east side of a wall and your dark look holds through the whole afternoon, while the rose still collects the morning sun.
Give your plant whatever light the rose needs to grow well, then do your looking somewhere else. Darker flowers absorb more light than pale ones, so midday glare beats the color every time. The plant needs sun to bloom, and your eyes need shade to read the color, so treat those as two separate jobs. Cut a stem in the evening and bring the flower indoors. Stand that stem against a pale wall or a white cloth and the black effect holds.
Photos are the weak link when you shop. A picture taken against a bright sky flattens the petals into ordinary red, and a picture taken in shade against a pale fence sells you a black flower. Neither shot lies. Look for a photo with a light background and shaded petals, because that setup shows you the darkest rose color at full strength.
If you cannot get that cultivar, other dark red roses land in the same place, because the effect comes from depth of color and not from a name. Buy with your eyes. Ask to see the bloom in shade before you pay, and walk away from anything that already looks bright red on a sunny bench outside the shop.
Read the full article: 10 Black Flowers That Are Not Truly Black
