Hands down, my favorite late summer and fall perennial bloomer of all time is the Japanese Anemone tomentosa ‘Robustissima’. An absolute non-stop flowering gobstopper for weeks on end by my front step from late August through October. Originally I chose this plant because it is known as the hardiest and easiest Japanese Anemone to grow, but soon it’s captivating wind flowers and bee laden blooms became my favorite September flower-power plant. In fact, bees can be found smothering the flowers the entire bloom season, so anemone is a lovely plant to attract pollinators to your garden. Best yet, this is the perfect perennial to toss in the ground then ignore for most of the season.
How To Grow Robustissima Anemone
While anemone love a rich, moist planting site, this particular variety will do well in average and even sandy soil. Add plenty of organic matter to enrich existing soil before planting. Robustissima Anemone is the most adaptable of all the anemone’s to drier conditions, but need more watering attention initially until they are established. Once established, plants form a low mound of green leaves with tall branching stems that produce interesting branches of bud balls that will develop into attractive soft-pink five petaled flowers.
Anemone Robustissima do well in full sun to part-shade and are tremendously easy to grow. I leave the seedheads up all winter for interest and clean the beds in early spring before green shoots redevelop. Divide every few years in the spring to keep the plants in check. Add additional organic matter like compost to the beds, mulching well, in the fall.