Certified GKH Gardening Expert
Some ornamental grasses can become invasive because of their seed plumes, while others do not. You would be best researching the specific type of grass you have to see if it is an invasive variety. Regardless, you do not need to remove the plumes as soon as they appear. They are the flowers of the grass, and just like your other flowers, the seeds don't develop right off the bat. They will be fully developed when the plume starts to brown and dry out and this is the time you have to cut them off to keep the seeds from spreading.