Genus
Centaurea
5 US plant patents have been granted in this genus. 2 are already in the public domain — anyone may propagate and sell them. The next of the 3 still protected comes off patent on October 28, 2028.
Still under patent — 3 cultivars
Soonest to come off patent first. You may not propagate these for sale until the date shown.
- Amethyst DreamPP20781Centaurea plant named ‘Amethyst Dream’UNDER PATENTOctober 28, 2028
- Black SpritePP23250Centaurea plant named ‘Black Sprite’UNDER PATENTJuly 22, 2031
- BalcentsirlPP35838Centaurea plant named ‘Balcentsirl’UNDER PATENTSeptember 22, 2043
Already in the public domain — 2 cultivars
Most recently freed first. Anyone may propagate and sell these plants — though the name it is sold under may still be a live trademark.
- Amethyst in snowPP18284Centaurea plant named ‘Amethyst in snow’PUBLIC DOMAINMay 22, 2026
- Gold BullionPP10865Centaurea plant named `Gold Bullion`PUBLIC DOMAINSeptember 22, 2017
A patent expiring frees the plant, and its cultivar name comes with it — cultivar names cannot be trademarked, so they are always free to use. What it does not free is any brand name the plant is marketed under. Those are trademarks and renew indefinitely.