Also prune this way

Herbaceous perennials with single, strappy leaves resemble deciduous grasses at this time of year. Like grasses, they are monocots and some will look better if pruned the same way, such as varieties of: hemerocalis iris sisyrinchium

Other herbaceous perennials left for winter can now be cut back, too. With evergreen grasses, simply pull a gloved hand through the leaves, removing any brown blades.

Take care when cutting back spent stems, ensuring you do not trim off any new growth