The Rockdale Gardener

Gardening Posts From Rockdale Cooperative Extension

Zoysiagrass Slow to Green Up This Year Especially in Shade!

Zoysiagrass needs lots of sun to properly green-up. Sometimes it can be as late as June before it gets green.

The sunnier up-slope grass has greened up while the grass that gets less sun has yet to green up.

I am seeing a lot of Zoysiagrass that is slow to green up this year. This slow green-up occurs on sporadic years.  It typically occurs in years when the weather conditions are just right. Basically, cool, cloudy and rainy extended spring weather can slow down the rate at which Zoysiagrass comes out of winter dormancy. Also mismanagement can cause slow green-up.

Here are some reason for slow Zoysiagrass green-up in the early summer of 2016:

  • Temperatures to low – The soils are still cool having just reached 75 degrees F in my area on May 3rd. Soil temperature is critical to signalling warm season grasses when it is time to come out of dormancy. Also, the air temperatures are still cool on average. In fact, the temperatures are supposed to drop into the forties this week! In years when we have cool temperatures into the early summer, Zoysiagrass can remain in partial dormancy until June! So do not fret if your Zoysiagrass is not completely green on May 3rd.
  • Not enough sunlight – There wasn’t much sun this rainy winter. Sunlight is critical to signalling dormant warm season grasses to green-up. Many people who think they have full sun are surprised when someone brings a light meter or uses the Popular Sun Seeker App to demonstrate that the yard gets less sun than they thought it did! In the picture above you can see that the sunnier part of the yard has greened up more than the shadier side. This yard was full sun 20+ years ago when the house was built. Now, the trees have grown and the sunlight is reduced. The yard really only receives enough light near the end of June when the sun is at its apex.
  • erosion kills grass

    Lower side of same lawn showing the effects of erosion.

    Rain causes erosion – rain has eroded sloping sandy soils out from under the roots of zoysiagrass in many Rockdale County yards. Two years of heavy winter rains have eroded slopes and killed grass.

  • Improper turf-care methods – DO NOT SCALP ZOYSIAGRASS!!! Bermudagrass can be scalped but not zoysia; i does not recover well. Do not fertilize too early either. Wait until the air reaches the 80s and soil temperatures above 70 F.

This old fact sheet from retired UGA professor Dr. Landry is helpful – “Zoysiagrass Greenup Problems”