August Emperor

August Emperor is a giant. At 57 inches it stands nearly five feet tall — one of the tallest Japanese iris in our garden and a genuine landmark plant at the back of a border or beside water. The flowers are a deep, saturated red violet, uniform throughout in what growers call a self, with the full doubled form that was prized in the mid-century American breeding programs.

Registered by Walter Marx in 1961 and introduced the following year. Marx was one of the great names in American Japanese iris breeding, working out of Oregon through the middle of the last century, and this is one of his lasting introductions. A cross of 'Summer Storm' × a Marhigo seedling.

It blooms late — after most other Japanese irises have finished — which makes it valuable for stretching color deeper into summer. Pair it with early and midseason varieties to carry the display across several weeks.

Japanese irises want moisture, especially through spring bloom season, and slightly acidic soil — they won't tolerate lime. Full sun gives the best performance. Hardy in zones 4–8.