Early Spring Growth: Let it Be
Watching the exciting finish to the 2018 Masters yesterday, was a reaffirmation for me and millions of “snow birds” that the official start of the golf season has begun. It’s like opening day in baseball. The pro shops and large retailers are packed with golfers buying new clubs, or re-gripping old ones, while the golf courses and driving ranges are packed through the weekend. All you have to do is drive by a driving range on Master’s Sunday to see people lined up three deep to hit golf balls. This year has been a little different, spring has been slow to come, with breezy cold conditions intermingled with snow showers and rain. To me it feels like “opening day” has been delayed.
Figure 1. The snow and cold in repeating cycles through most of the northern United States has delayed a "normal" spring.
The cold wet spring has impacted turf growth too. Like golf’s “opening day” course, conditions have been slow to get going. Slow or disproportionate growth is occurring, which is most obvious in the roughs and on greens. In roughs where tall fescue, Kentucky bluegrass and perennial ryegrass co-exist, the differential growth rates are striking. Tall fescue vertical shoot growth is considerably more aggressive than either Kentucky bluegrass or perennial ryegrass. Often the pronounced clumping of tall fescue is most evident at this time. In rough or higher height of cut turfs tall fescue when present often dictates when mowing begins.
Figure 2. Tall fescue foliar growth occurs quickly ahead of Kentucky bluegrass and perennial ryegrass in the spring. The patchy appearance of tall fescue is most apparent in early spring.
On putting greens, annual bluegrass (Poa annua) is growing at a relatively rapid rate. In contrast, creeping bentgrass (Agrostis stolonifera) is growing at a much slower rate and often appears to be not growing at all. In response to the difference in growth it is not uncommon to see a blotchy appearance on putting greens due to the greater density of the annual bluegrass and color differences between the two turfgrasses. Additionally, the difference in growth rates makes the greens bumpy due to annual bluegrass’s faster growth rate.
Figure 3. Early spring growth of creeping bentgrass is slower than annual bluegrass.
Often the tendency is to try to push creeping bentgrass to get it growing at a more rapid rate. Creeping bentgrass however is on a different biological clock than annual bluegrass. Research on both root and shoot growth report that creeping bentgrass growth comes later in the spring. What this means is if you have developed a solid fertilization program, don’t try to adjust it to “jump start” the creeping bentgrass by giving it subsequent shots of nitrogen. The creeping bentgrass doesn’t want the excessive nitrogen. The impact can actually be detrimental to creeping bentgrass root growth. The excessive amounts of nitrogen applied at the time of creeping root growth may stunt growth in favor of trying to push leaf growth. The implications will be felt later in the year. And in actuality you are most likely favoring more growth from annual bluegrass.
In addition, don’t be excessive in your mechanical practices to get perfect putting green quality from creeping bentgrass during these cold periods. It's normal for wider leaf blades, and stoloniferous growth to be occurring with creeping bentgrass at this time. Unfortunately, these growth characteristics are often in stark contrast to annual bluegrass.
Although it’s normal to be excited for a new golf season and match the expectations of golfers on “opening day”, recognize especially on mixed creeping bentgrass and annual bluegrass greens that each turf grows and develops to its own drummer. Let the turfgrasses, especially creeping bentgrass, start growing at their own pace.
Given that realization that grasses have their own pace of development, what can we do to mitigate the differences and not impact negatively the health of the turf? Plant growth regulator applications like trinexepac-ethyl (PrimoMaxx®) applications can be started when foliar growth starts. In early spring this would be timed with annual bluegrass foliar growth. In combination with light rolling the putting green will be smoother and differences in growth less obvious. Light mechanical practices like brushing, verticutting and topdressing should help improve creeping bentgrass leaf texture. Once consistent warmer temperatures arrive the differences in growth will disappear. By allowing creeping bentgrass to start growing on its own, you will have a healthier turf through the coming summer months.
About the author
Dr. Karl Danneberger is a professor of Turfgrass Science at The Ohio State University. Dr. Danneberger's contact information can be found here. You may also follow Dr. Danneberger on Twitter: