Henry™ III Purple Aster

Henry™ III Purple is a purple, double-flowered selection in Syngenta’s Henry™ III series of New York asters. The breeder lists product 70018153 for fall garden flowering, with 16–18 inch height, 20–24 inch spread, and medium vigor ([Syngenta Flowers](https://www.syngentaflowers.com/ams/product/flower/70018153)). ## Form and Placement The compact dimensions suit the middle or front of a sunny perennial border and allow use in an appropriately sized container. Syngenta describes its production crop as mid-season; that is crop timing, while the same product page lists fall as the garden flowering season. ## Growing Conditions Provide full sun. General New York aster guidance recommends fertile, moist but well-drained soil and tolerates partial shade; species-level advice can guide care while the breeder’s page supplies the cultivar’s size and flower details ([RHS species profile](https://www.rhs.org.uk/plants/1768/aster-novi-belgii/details)). ## Maintenance Keep soil evenly moist while establishing and avoid winter waterlogging. Divide established clumps every few years to maintain vigor. Remove spent stems after flowering; leave enough air movement around foliage to reduce powdery mildew risk ([RHS Aster growing guide](https://www.rhs.org.uk/plants/aster/growing-guide)).