Ornamental grasses….the time is nearing….

Categories: Seasonal maintenance

Ornamental grasses continue to gain in popularity as a landscape plant.  Grasses tend to work very well for our climate as they generally use less water than other landscape plants and hold up very well in our summer heat.  Personally, I enjoy grasses for two other reasons.  I love the way they dance in the Oklahoma wind.  I also enjoy the fact that they often are at their best (from an ornamental display perspective), in the dead of winter when their seed-heads remain prominent against a faded winter landscape.

Grasses are also low maintenance requiring only one well-timed cutting back each year and an occasional division as the plant matures.  Timing the cutting back is very important.  Doing this too soon and you risk winter injury as the crown of the plant relies on last season’s growth to help insulate it.  However, if you wait too late to cut it back, you’ll damage the growing tips of the leaves and you’ll be left with a ragged appearance all season long.  This is not a big issue for the finer leaved grasses like Miscanthus,  but it can be very unattractive on those with wider leaf blades like zebra grass or the common grass-like liriope (monkey grass).

I would suggest you begin checking your grasses right away for spring growth.  As you’ll see below, some of them are well on their way already.

This photo of blue grama was taken on Feb the 3rd. As you can see, new growth has begun.

As you can see in the second photograph, it is very difficult to detect any signs of spring growth unless you get down close and dig around a bit.  I checked several other species today including liriope and this plant was ahead of everything else I checked.  Please keep in mind micro-climates can have a tremendous effect on the timing of green-up so your landscape could vary quite a bit compared to what you are seeing here.

The same plant as seen from a distance.

As to how far you should cut back?  That’s somewhat subjective and a matter of personal taste and the equipment you have on hand to do the job.  Personally, I like to get down to within a few inches of the soil surface.

This is also a great time to divide grasses to rejuvenate them or share with other gardeners.  If you’ve not attempted this before, be forewarned!  The root mass on these plants can be TOUGH!  Don’t worry too much about hurting the plant, just take care not to hurt yourself as you divide them!  After going a few rounds with some mature perennial grasses, you’ll be very pleased with the fact that this is a once-a-year endeavor!

Don’t hesitate to contact me if you have any questions.

Keith Reed, Payne County Horticulture Educator