Pruning lady's mantle encourages a robust display of blooms by removing spent flowers, which stimulates further flowering. It also maintains the plant's vigor, ensuring that lady's mantle grows densely and healthily. Shaping lady's mantle by pruning keeps it within desired bounds, enhancing its mound-like appearance and preventing overgrowth.

In late spring, after the threat of frost has passed, lady's mantle has typically finished its main blooming period and can be pruned to remove spent flowers and to shape the plant, which encourages a second, though less profuse, bloom and fresh foliage growth. Summer pruning may be necessary to remove any damaged or diseased foliage and to maintain the plant's size and appearance, which is particularly important as lady's mantle can spread vigorously. Early fall is an acceptable time to trim back the plant as well, especially to remove any old or faded leaves and to prepare lady's mantle for winter by reducing the amount of dead plant material that could harbour pests or diseases. However, pruning should be completed well before the first frost to prevent damage to the plant. It's advisable to avoid heavy pruning in late fall as this can stimulate new growth that is vulnerable to winter cold.