When is the best time to prune my Common yarrow?

There are two primary forms of pruning for Common yarrow. The first is deadheading, which is the gardening term for removing spent flower heads once they start to wither. This concentrates the nutrients for the other flowers and allows the plant to flower better. The final process for pruning Common yarrow is the removal of yellow and diseased leaves, which increases plant ventilation and light penetration and facilitates plant growth. Since Common yarrow requires two types of pruning, you’ll be trimming your plants throughout the growing season. Pinching is most effective in the early spring before the plant develops any flower buds. Removal of yellowing or diseased leaves can be done at any time during the growing season. When nature runs its course, Common yarrow will bloom once, produce seed heads, and attempt to reproduce for the rest of the year. But, by consistently removing flower heads before they go to seed, you encourage the plant to continue producing more blooms for a longer flowering time. Finally, deadheading takes place as soon as the plants are producing full flower heads. Expect to take off spent blossoms from mid-summer through the first frosts of fall. When the plant starts to wilt during the full, you should cut off the wilted part above the soil as well.