Time to Cut Down Ornamental Grasses (2024)

FAQs

Time to Cut Down Ornamental Grasses? ›

You can do the job in the fall after the foliage dies, or leave it in place through the winter and cut it back in the spring. Some ornamental grasses will remain attractive through the better part of the winter.

Cut back cool-season grasses in very early spring.

Leave their foliage in place until spring and then as soon as the snow is gone cut them back. Leave about 1/3 of the plant in place. Trimming cool-season grasses too harshly can irreparably harm the plant.

Good Growing Tip of the Week: Cutting or burning your ornamental grasses in the spring does have a benefit. When foliage is removed, spring growth will begin earlier. Old foliage left on the plant can delay the crown's warming and subsequent growth by as much as 3 weeks.

Usually division every two to three years is appropriate. Dividing ornamental grasses is best done in late winter or early spring before growth starts. Divide even a small plant if you want to grow more.

Answering your first question on how to thin out the plant and what to do with the falling outer “stalks” (flowers) --the best time to prune fountain grass is late winter or early spring--but be sure to prune before the grass begins to re-grow. Also avoid pruning in the fall before the plant has had time to go dormant.

Use the cutting tool(s) of your choice to cut through the grass. The large, established grasses may require more than pruning shears – this is where the power tools such as the weed eater with a blade or powered hedge trimmers or even a chain saw for Pampas grass is necessary.

Grasses generally grow best in three to five hours of direct sun each day. In shade, these grasses may not bloom, are often lax and tend to fall over, and may not develop peak fall color. Most grasses can benefit from mulching and many from cutting back, usually just before new growth begins in the spring.

You can use a variety of tools to prune your grasses. I have some pruning loppers and pruning shears here. You can also use electronic hedge trimmers, gas powered hedge trimmers, a thick pair of scissors, and other tools. You'll also want to use a pair of gloves.

However, with the right care, your grass can last you years. Typically, the lifespan of your grass is about 7-10 years.

Once established most ornamental grasses are drought tolerant and only need to be watered during extended dry periods. Allow the grasses to stand for winter. They provide food and shelter for visiting birds and beneficial insects.

Why does my ornamental grass look dead? ›

Answer: The centers of ornamental grasses often die as the plants get older. When this occurs, it's a good time to dig and divide the grasses. When the grasses begin to grow in spring, dig up entire clumps, cut out and discard the dead center portions of each clump, cut the outer portions into sections and replant.

Pampas grass should always be cut in the spring, once the days have become frost-free. The interior of pampas grass stems are hollow. If you were to cut your pampas grass in autumn, water would accumulate there and the plants do not like that at all.

If you live in an area that is susceptible to wildfires, it's important to cut back your grass as soon as it goes dormant in the fall. The important thing is to cut back ornamental grasses before new growth emerges in the spring. Pruning grass during the dormant period helps prevent any potential damage to new shoots.

Most ornamental grasses are left standing in the winter months and are cut down around March before the start of any new growth. They are cut to 3″ above ground with a sharp pruner, hook knife or electric hedge trimmer.