Putting green collars are often one of the first areas to thin out during periods of stressful summer weather. There are several factors that contribute to collar decline, with the most notable issues being concentrated traffic from golfers and maintenance equipment and overregulation from plant growth regulators (PGRs). The following tips can be used to help reduce the likelihood for collar decline:
- Use smooth or segmented front rollers on mowing equipment. Grooved rollers can help promote upright growth, but they also increase mechanical injury. Light brushing can be used if necessary to manage lateral growth.
- A mowing height of 0.250-0.350 inch often improves collar performance compared to heights above 0.400 inch. A lower mowing height improves plant density, thus improving wear tolerance. This lower mowing height is especially beneficial for creeping bentgrass collars. Reducing the height of cut also reduces the impact from PGR overregulation. Some courses have gone as far as lowering the height on their bentgrass collars to putting green height, essentially replacing the collar with more putting green area.
- Using turning boards is recommended when walk mowing greens where operators do not have ample room to turn in the rough. This is especially important for creeping bentgrass collars. The USGA Green Section video “Protecting Collars with Turning Boards” provides some good tips on the use of turning boards. The key is to make sure the mowers are turning completely on the boards and not on the turf.
- When rolling greens, avoid stopping and starting on the putting green perimeter and collar. Failing to do so can quickly lead to abrasion and turf thinning. Good roller operators should be able to slowly and carefully stop and start on the putting green without going within 3 feet of the perimeter. Stopping and starting in the rough is another option, though this may not be possible if there are steep slopes or bunkers around the green.
The increase in rounds played over the last couple of years at most facilities is also adding traffic to collars in entry and exit points around putting greens. The increased business is certainly a good thing for the golf industry, but additional traffic in an area that already receives concentrated traffic from maintenance practices can lead to further decline. Implementing these strategies should help to promote healthier collar turf throughout the season.
Central Region Agronomists:
Paul Jacobs, agronomist – pjacobs@usga.org
Zach Nicoludis, agronomist – znicoludis@usga.org