In any other sport involving a ball, we wouldn't accept trees in the playing field.
Trees and Golf Agronomics
There is an art and a science involved in maintaining an exceptional golf course. Let’s start with maybe the easier of the two, the science, and how trees affect that science of bentgrass greens.
Grass needs sunlight to grow and air movement to stay cool; aesthetics, strategy, and emotions aside, it’s fairly simple. Regardless of how skilled and qualified your grounds management and staff may be, trees planted in inappropriate locations will reduce turf quality. Trees planted to the east and the south of greens will negatively affect turf conditions. As trees continue to grow, shade conditions will worsen. Trees that block the necessary morning sun and impede air movement will continue to make the greens’ turf weaker during the summer months.
It has been one of those near certainties in my thirty plus years in golf…that the best green on almost every golf course is the highest, largest, most sun baked and windswept green on the course. Conversely, the worst green on almost every golf course is the lowest, shadiest, smallest green with stagnant air movement. Bentgrass loves sunlight and air movement.
Cool season turfs, including bentgrass, wake up in the morning and begin to photosynthesize. The bentgrass will take in the available nutrients and water and turn them into energy in the form of carbohydrates. In the heat of the summer when the stresses of summer are present, the bentgrass on your greens needs to carbo-load before the start of the heat/endurance race for the day. It takes sunshine and cooler soil temperatures to do that.
Imagine two marathon runners, one carbo-loads and has the available energy to run the race, the other takes in a third as much in carbohydrates and peters out in the race. Which runner do you want your grass to be in the summer? Do you want a grass that has more energy or less energy? Selective tree removal that reduces or eliminates shade on greens from dawn until two in the afternoon will improve the stress tolerance of your greens and result in improved putting surfaces.
Air movement on greens improves the cooling potential of the grass and will reduce soil temperatures. Bentgrasses flounder as soil temperatures reach the upper seventies and higher. Increasing air movement to greens will help the grass and soils cool themselves off in much the same fashion as swamp coolers do or how we might stand in front of a fan on a hot day and feel cooler. Air movement can and should be enhanced through the removal of vegetation that restricts air movement and the addition of fans (surface and subsurface). These fans will improve overall turf health by cooling plants and soil off and reducing the humidity in the turf canopy.
How do trees affect the art of providing an exceptional golf course?
Thirty years ago I worked at Merion Golf Club, which many consider acre for acre to be the best course in the world. At Merion, the tree program was proactively managed down to the last detail.
Trees were never planted in linear rows. Never. They were clustered, which gave a sense of forest while still being positioned to achieve planned and aesthetic goals. Strategy and Member enjoyment were considered whenever possible by locating these clusters 275 yards from the tee on the left side of the fairway, not 225 yards on the right side unless they would knock down your ball and keep it from going OB. Merion even planted White Pines (tallest grower) closest to the tee, Austrian Pines going down the fairway and lastly Scotch Pines (smallest grower) further down the hole.
So how should you plant or remove trees to better your golf course:
• Identify the trees adversely affecting your agronomics first.
• Agree that clusters of trees are always better than linear rows of trees.
• Trees, like bunkers, can be placed to make the course more challenging for a low handicap and more enjoyable for a higher handicap.
• Take advantage of the topography of your course and open up some of the vistas.
• Remember all trees grow and in doing so shade will become more of an issue each year.
• When planting or replacing trees, plan based upon the trees mature height and spread.
• Have a plan!