What Is That Purple Colored Grass?

So have you seen that purple topped grass growing in the ditches, in pastures, along fields and in waterways recently?  This grass is called just what it looks like, “Purpletop”.  Another name for this grass is greasegrass.  This year I have just seen some of it showing up in pastures and along roads.  When we had the drought in 2012, it didn’t show up much.  If you are concerned about it being a problem weedy grass, it shouldn’t be a problem.  It has shown up this time of year the past few years, especially when we get some good rains during the summer.  

Purpletop is a perennial grass that is well adapted to poor soils.  It grows where other cool-season grasses do not produce well.  It can be found on shallow, drought and infertile soils.  Since it is a warm-season grass, it doesn’t show up until late summer.  During the spring and early summer, cool-season grasses, such as brome are very competitive and crowd it out.  On good soils, purpletop usually doesn’t establish very well.  This is why it shows up on poorer soils in August, when cool-season grasses are less productive.  It was probably planted in grass mixtures for pastures and as cover along roadsides and in waterways.  It spreads by seed and rhizomes. All livestock consume it, although the quality is best if grazed in the vegetative stage.  It will respond to fertilization as well.  I don’t think you need to get too concerned about it taking over your pastures, as long as you keep the fertility level up on them and follow recommendations. This year with the rains we have had earlier this summer, purpletop is showing up along roadsides and in pastures. As I have mentioned in a previous article, now is a good time to identify problem areas for weeds in fields, pastures, roadsides and around the farmstead. If you have any questions about this grass or other issues, feel free to call me at (402) 274-4755 or (402) 274-9639 (cell).

Gary Lesoing
Extension Educator
Nemaha County
August 2021

Purple Colored Grass