Poa removal from collars

Last year we renovated the collars on the course. Previously, they had been a mixture of several different grasses. We resodded them to bentgrass and the results after a full season are good. However, regardless of what grass the collars are, annual bluegrass or Poa annua, will invade. To keep the annual bluegrass from gaining a foothold we must remove it.

The collars are the narrow strip of grass immediately outside the green, between the green and the rough. Here is the post from when we started the project last spring. Before the sod, annual bluegrass was one of several types of grasses mixed in the collar. Annual bluegrass has many positives- our greens are over 90% annual bluegrass- but it also does poorly in some situations. The collars are one such situation where it was not ideal. Bentgrass is much better at handling the many stresses that the turf on the collars endure and was thus a major upgrade.

A very small plant just to the left
of the tip of the knife. Notice the small
seed heads.

However, annual bluegrass is highly adaptable and drops highly viable seed every season. This seed can make its way nearly anywhere: it gets blown in wind or from our blowers, it gets moved by our mowers, it can even be relocated by golf shoes. The seed does not need much attention or space to work, and it will start to grow. Poa annua grows fast, and in just a couple of months can carve out a spot for itself right in the middle of the bentgrass collar and continue to increase in size.

Slightly larger annual bluegrass plant

Our goal is to maintain the bentgrass collar without letting the annual bluegrass get back in. This requires constant vigilance. That small seed can become a plant the size of a quarter in a few months. Then it will continue to grow, set its own seed, and more plants will arrive. Soon you may have a half dozen plants in a small area, then they seed, and so on. After a season or two, there could be sections of a collar that are 25% annual bluegrass. Left unchecked, the annual bluegrass would likely make up 50% of the collar turf after several years, which would take us back to the situation prior to the renovation.

So, to keep the Poa annua at bay, this spring we started cutting out the small plants in the collar by hand. Many courses that renovate their greens, or any surface, to bentgrass will have spent some amount of time cutting small annual bluegrass plants out of the greens. This is a common practice, and though it can be labor intensive, it is quite effective. The key is to start right away, before the annual bluegrass plants mature and get larger.

Using a small knife, we cut just under the Poa plant and physically remove it. A small scar is left, but the bentgrass is growing strongly enough to fill in quickly. It will be impossible to get every plant, and even so, more would germinate the next season. But we get everything we can, and we do it every year at least once.

An annual bluegrass plant about the size
of a golf ball

There is nothing on the golf course that we can fix, or renovate, or improve, and then leave alone. No matter the project, upkeep will be required to maintain the new feature. The collars are no different. Manually cutting the Poa annua out of the bentgrass sod is one of the keys to prolonging the purity of the collar sod.

 

Etiquette Reminder of the Month

Please remember to remove any bunker sand that may be stuck to your spikes before walking on the greens.

Also, as part of a Golf Committee initiative to improve course etiquette, we have included links to videos teaching proper on course etiquette. Please take a moment to watch:

Ball Marks - How to properly repair

 

See you on the course!

Joe

jvillegas@bwrc.org