Crowded Sedge

Plumeless thistle is a low-maintenance plant that should be watered when the top inch or 2 of soil has dried out. If the soil is very sandy, it should be watered more often. Plumeless thistle needs a deep watering every 1 to 2 weeks during the spring and summer. In the fall, it may need slightly less water. In the winter months, water less frequently as the plant becomes dormant and requires little moisture. Make sure to water the entire root area of the plant and avoid overwatering.

Plumeless Thistle needs at least 6 hours of direct sunlight each day in order to thrive. Typically, it should receive full morning sun, with shade in the afternoon during the hottest part of the day. This will help to reduce leaf scorch and over-heating of the stems. When temperatures are highest, Plumeless Thistle should receive some shade. In cooler climates, it can tolerate more sun than in hot areas. The more direct sunlight it receives, the healthier the plant will be and the more prolific its blooms.

Plumeless Thistle should be pruned in late summer or early fall when it is actively growing. Remove only 1/3 of old flowering stalks at once, leave some of the flowering stalks in place to keep the color of the blooms in the garden. Monitor the foliage closely and prune the remaining flowering stalks before they flower for a second time in late summer or early fall. Prune the foliage back to the lowest foliage bud in each stem, leaving the flowers on the stem to mature and produce viable seed. By pruning in this fashion, the plant will maintain its shape and vigor, as well as its long-flowering season.