If your course falls into this category, consider the following:
- Tree work will be needed around many of the greens that now have higher bentgrass populations. The environment that sustained a bent/poa turf may not have enough light for bentgrass to be competitive. Bentgrass has a high light requirement and light penetration must be maximized at all times of year for it to have a fighting chance against annual bluegrass.
- Rethink your cultivation program. Remember that annual bluegrass is a winter annual and aerating or performing surface cultivation during the window of germination will promote annual bluegrass at the expense of newly established bentgrass.
- Creeping bentgrass got its name for a reason, it “creeps.” Using solid rollers, even at lower cutting heights, helps promote lateral growth. Periodic verticutting in the spring and early summer months also can promote more gains in bentgrass, but avoid frequent, aggressive treatments that cause constant wear injury. Constant wear injury tends to favor annual bluegrass.
- Keep wear injury in mind, particularly in lower light environments. Annual bluegrass is more wear-tolerant than bentgrass, and a high-wear program (e.g., frequent double cutting combined with frequent rolling) will likely do more harm to bentgrass than annual bluegrass.
- At many courses annual bluegrass remains the primary turf species on putting greens. This is largely a result of our ability to keep the weaker grass alive. Greens that are predominantly annual bluegrass require lots of inputs. If the specie composition of your turf has changed dramatically as a result of winter injury, rethink your management strategies. Many of our fungicide applications are targeted at diseases of annual bluegrass such as summer patch and anthracnose. If bentgrass populations are high enough, these diseases can control the grass you want to get rid of.
- Depending on how much new bentgrass you now have in your greens, other options to consider include annual bluegrass-suppressing growth regulator treatments this year and possibly forgoing seedhead suppression treatments next spring. Suppressing seed heads is good for playability, but it also makes annual bluegrass stronger which may not be in your best interest going forward.