My Healthy Looking Acillia Plant Has 80%less Flowers This Year, Why?

Question

There are three plants and last year they all flowered beautifully, this year only one of the plants has a few flowers. The foliage looks good and I don’t think they are crowded, this is their third season. I live in Cornwall, the plants are in full sun in well drained soil

Answer 1

Typically, this will be due to there being too much nitrogen in soil. If the area get fed, be sure that this is not high in nitrogen.

The excess nutrients will leach out over time.

This article will give you more information on the care of the plant:

https://www.gardeningknowhow.com/edible/herbs/yarrow/growing-yarrow.htm