I don’t often mention green maintenance in my golf lessons. Nor do I often discuss it in my golf tips. That’s because golfers want to talk about hitting the ball instead. But the care and feeding of a club’s greens—how they are mowed watered fertilized— can have a major impact on a player’s golf handicap especially if he or she plays the same course a lot.

Speed is the key factor when considering green maintenance. Usually players want a superintendent to increase green speed. It’s probably the most frequent request about greens. Occasionally players want a superintendent to decrease green speed but these requests are few and far between. Misjudging the speed of a putt can add strokes to a score as I’ve mentioned in my golf tips.

The term “green speed” is technically inaccurate. The device measuring “speed” —the USGA Stimpmeter —gauges the distance a ball rolls when released at a controlled speed on a putting surface not the ball’s velocity. To talk about green speed then is a bit of a misnomer. Nevertheless we continue to use the term when talking about greens. (I even use it when giving golf lessons.) A green with a relatively long ball roll is considered “fast.” A green with a relatively short ball roll is said to be “slow.”

Ball roll relates to relationship between the initial energy when a putter strikes the ball and the resistance between the ball and the turf’s surface or friction. As the ball rolls across the green its surface slows it down thanks to friction. A green with high resistance slows a ball down more than a green with low resistance. Moderating friction changes a green’s speed.

Environmental factors such as humidity can moderate friction and change a green’s speed. For example high humidity increases green speed a consideration when playing on a hot day. Soil type also influences green speed. Greens made predominately of clay are faster in spring than their sandier counterparts. While superintendents have little or no control over these factors they have minimal impact on your game.

Management practices on the other hand like mowing or irrigation can make a profound impact on a green both short-term and long-term. Below is a summary of how some popular management practices affect green speed.

Mowing:

An effective way of increasing ball roll in the short-term mowing has a significant impact on green speed. Decreasing mowing height by only 116 inch can increase ball roll from 6 to 10 inches. A similar response occurs when you “double cut” a green (mowing it a second time perpendicular to the first cut) which can increase ball roll 6 to 12 inches. Mower type also influences green speed. Greens cut with a walk-behind mower are generally 6 to 8 inches fast than greens cut with triplex mowers.

Irrigation

Dry greens are faster than moist or wet greens. Withholding irrigation or decreasing it before an event requiring faster greens will increase ball roll 4 to 8 inches depending on soil type.

Rolling

Rolling golf greens isn’t new but it’s growing in popularity thanks to new research and better equipment. Depending on the type of roller you use you can increase green speed from 4 to 10 inches with minimal compaction problems on sand-based greens

Topdressing

Light frequent topdressing with or without vertical mowing or core aerating is common. Topdressing decreases speed for up to 1 week after application followed by an increase of from 4 to 8 inches (above the speed before topdressing.) Vertical mowing has a similar effect. Core aeration reduces speed initially and if you don’t topdress to fill in the holes decrease it long term.

Fertility

Decreasing nitrogen fertility will gradually increase ball-roll distance. A decrease in nitrogen fertility of only 10 percent can increase ball roll 8 to 12 percent. The effects may take up to a year to see however depending on previous fertility practices. Plant growth regulators can increase ball roll from 4 to 8 inches depending on product rate and frequency of application.

Keep in mind that these factors do not operate independently. Modifying one may require compensation by modifying another.

Next time you play your favorite course be aware of these factors and how they affect a green. Take them into account when putting. Doing so might just help you improve your round and your golf handicap.