Summertime Green Speeds and Height of Cut

Currently we are approaching the end of the "dog days" of summer. We are at the point where we can start to be a little less conservative with greens rolling, as well as start to lower the mowing height back to normal.

During the heat of the summer when higher temperatures and heavy downpours can come unexpectedly, we must stay on the defensive with our cultural practices. Rolling, brushing, and low mowing do damage that accumulates over time as stress increases and recuperative ability decreases due to high temperature and humidity.

Being that we are getting closer to when the turf can readily recover, I can start to push the greens more. In fact, we are planning on starting to roll some this week and lowering mowing heights gradually over the next 7 to 10 days...with the extended forecast calling for low 80's. We topdressed yesterday and John is grinding the greens mowers tomorrow in anticipation.

Currently, the greens are being mowed daily and we use a combination of growth regulators and light weekly applications of fertilizer to control growth. The speed is slower than usual due to the increased mowing height more than anything. During times of stress the height of cut is raised so the turf can produce more food for itself. Although it seems minor, raising the height from .110 to .130 creates a lot more leaf area for photosynthesis. Unfortunately that small increase, combined with the summer humidity, will cause a decrease in speed.

Last year I made the mistake of pushing for green speeds too hard and paid a price when the heat and humidity came and never let up. In that scenario the slow speeds came in late summer and fall due to the need to recover from summer thinning. I'm sorry for the reduction in speed over the last few weeks but our greens and collars have held up well for the most part and I think we are now out of the woods. That sets us up for a great fall season instead of pushing growth and recovery.

The speeds will increase over the next week or two leading up to aeration and then obviously they will be slower for a couple weeks after that. After they heal, you can expect them to get even faster throughout the fall season. We have been doing more frequent topdressing which will help with speed and firmness when the humidity and temps start to drop. We will also be doing a less aggressive aeration on the greens this fall so recovery time will be shorter than this past spring.


Thank you for your patience through this critical period of balancing health and playability.


For a detailed look at the science behind mowing heights please follow the link below.


USGA Green Section Article - Bent Grass Greens Mowing Height