The cutting edge
Few in the turf industry can remember the days of using hand shears, straightened hoes and half-moon edgers for edging. Those of us that do remember do not have the bodies left to perform such laborious tasks. Can you imagine the labor cost today if more time-saving devices had not come on the market?
Mowed turf does not look complete until you provide clean lines with edging. Nowhere is this more evident than the crisp line between turf and the skinned infield of a baseball diamond. However, landscape beds also require edging to prevent encroachment of adjacent turf and maintain a well-groomed appearance. With aggressive stoloniferous grasses such as bermudagrass and St. Augustinegrass, edging can become a monumental task, especially on large sites such as golf courses, parks and large commercial landscapes.
Though many people think of edging and trimming as essentially the same thing, they are not synonymous. Edging means cutting the grass for a neat appearance along the edge of the turf, whether it borders a bed, a bunker or pavement. Trimming means cutting grass that mowers could not reach around poles, trees and other objects. However, both trimming and edging are necessary to complete the groomed look.
Choosing an edging tool The right edging equipment is vital for making efficient use of your labor. Several options for edging are available to you: spin trimmers, metal edgers (hand-held and walk-behind) and vehicle-mounted edgers. One is not inherently better than the others, and most turf-maintenance operators own more than one type.
* Spin trimmers. Spin trimmers are a popular choice among many turf professionals for both edging and trimming. The advantage of spin trimmers is that you can use the same piece of equipment to edge and trim. The disadvantage is that spin trimmers are slower than equipment designed especially for edging. In addition, it's more difficult to achieve a uniform straight edge with string trimmers and you'll likely become fatigued after prolonged use. Your choice may come down to the characteristics of the particular site and operator skill and preference. Sites with little or no pavement edges may be suitable for spin trimmers (making it unnecessary to even unload your edger), whereas large amounts of edging may be far easier to handle with a true edger.
* Hand-held edgers. Although self-feeding heads and better quality have increased the productivity of spin trimmers for edging, metal edgers are still more efficient, and the labor they save will easily pay for their cost if you have much edging. Hand-held edgers, often called stick edgers, are similar to spin trimmers, using the same type of 2-cycle power source (see photo, far right). The head usually consists of an 8-inch metal blade and a wheel that enables the operator to rest the cutting head on the surface, assuring a straight line.
When edging on grassy surfaces around bunkers or landscape beds, you can use an optional wider wheel on most models of stick trimmers. This helps reduce operator fatigue because some of the weight rests on the wheel.
* Metal edgers. Traditional powered metal edgers have been around for decades (see photo, above center) and continue to be popular, though they are not as maneuverable as hand-held edgers. All metal edgers work by using a spinning metal blade to cut a uniform, straight line giving a formal, neat appearance. Blades are of different configurations. Typically, they are straight and flat, but some are configured as a scalloped disc for different grasses and applications. You can put quite a bit of wear on edger blades before you need to replace them, though you lose depth-of-cut as the blades wear down. Some people use two blades to double the width of the cut, but this is not necessary for most jobs.
* Vehicle-mounted edgers. Edging is necessary on almost all concrete cart paths or footpaths on golf courses. A 7,000-yard golf course that has cart paths tee to green could have more than 7 miles of edging. Proper equipment selection is important to reduce labor costs on such large areas.
Edgers mounted on utility vehicles are certainly the most labor-saving edgers on the golf-course-maintenance market today. These devices allow one operator to drive down golf-course paths and edge at a fairly high rate of speed. This type of edger is a tremendous labor saver and should be the superintendent's edger of choice if situations warrant and the budget allows.
Bunker edging Over time, bunker edges can grow inward several feet reducing the size of the bunker and obscuring the architect's intent. When bunkers grow in this manner, you often have to dig or probe to find the original perimeter. To maintain the original shape of a bunker, you must edge it regularly. This will minimize grass encroachment into the bunker. Edging frequently with manual tools, spin trimmers or reciprocating trimmers minimizes the need for more severe edging. With aggressive turfgrasses and favorable growing conditions, you may need to edge bunkers every 2 weeks.
Some golf-course superintendents like a more natural look for bunker edges. You can achieve this effect by letting grass grow down the bunker face to the level of the sand while using a spin trimmer to keep edges trimmed.
If you desire a "cookie cutter" effect in your bunker's appearance, a blade tool or trimmer with a reciprocating head will eliminate grass growing on the bunker face. Remember that the back side (fairway side) sand and grass should meet. This allows the golfer a fair chance to hit the ball if it comes to rest at the interface of sand and turfgrass. During all edging procedures, be careful not to contaminate the sand with grass trimmings more than necessary.
Trimming Unless you want to go back to hand clippers, spin trimmers are your only choice for trimming. No other piece of equipment is more labor-saving, economical and easy to operate. We take them for granted now, but you only need to think back a few decades and remember the alternatives to appreciate their value.
Some trimmer heads offer automatic feed, others semi-automatic feed (tap-and-go), while others are manual (you stop the trimmer and manually pull the string from inside the head). Fixed-line heads require you to install a new piece of pre-cut line each time the line wears down. Your choice depends on your operation. Operators or tasks that are hard on heads, such a s with inexperienced crews, may benefit from fixed-line heads because they are simpler and more dependable (and thus create less downtime for unskilled operators). The drawback is that trimmers are designed to operate most efficiently when the string is a certain length. Because operators tend to wear the string down to a nub before replacing it, the greater reliability of fixed-line heads is countered by lower operating efficiency. With experienced operators, however, few would argue that tap-and-go heads are more efficient.
It goes without saying that you should protect young trees and those with thin bark from trimmers. If you damage the cambium layer (just beneath the bark), you can seriously injure or kill the tree. If turf extends up to the trunk, protect young trees with a trunk guard or wrap. The best protection is to have an area of at least 12 inches from the base of the tree devoid of turfgrass and weeds by applying a non-selective herbicide and then 2 to 4 inches of mulch. This avoids the need to trim around trees altogether.
On more mature trees, apply a non-selective herbicide with a pre-emergence herbicide up to 15 inches out from the trunk (any further will distract from a neat appearance). Consistently using that measure combined with today's maneuverable mowers easily allows you to maintain a neat appearance around trees without even using a trimmer.
As with trees, trimmers easily can damage various hardscape materials, such as wood, painted surfaces and plastic. Therefore, in addition to trees, you must be wary of trimming too closely with spin trimmers. Using non-selective herbicides will prevent or eliminate growth adjacent to such objects, eliminating the need to trim around them.
Spin trimmers are notorious for throwing rocks, dirt and other debris into the air. This is especially true when you use the trimmer for edging (with the string spinning in a vertical plane). Often, flying debris merely stings, though it can produce cuts. More importantly, it poses a hazard for eyes. Always wear protective goggles when operating a trimmer. The same precaution applies to edgers, which can throw up small pieces of concrete in addition to other debris. Be sure other people are clear of the work area before you use a trimmer. Plus, use caution around vehicles, windows or other structures that flying debris could damage. Often, all you need to do is lower the throttle to prevent the trimmer from throwing debris.
Both string and metal blades can cause serious injury. Before performing any maintenance on blades or string heads, turn the engine off.
Other edging options
As equipment and labor become more expensive, chemical edging with plant growth regulators (PGRs) may gain more popularity. Several PGRs now available are good for this purpose. I'm sure that in the future we will see more come on the market to save on edging and trimming costs.
Turfgrass selection in the construction of large turf areas gives the turf professional another option for reducing edging and trimming. For example, zoysiagrass is slow growing and has similar color, texture and density to bermudagrass. Therefore, in the warm-season and transition zones, you can install zoysiagrass on bunker edges, steep slopes or along paths to reduce the labor needed for edging. You may be able to think of similar situations where you can replace Kentucky bluegrass, a creeping species, with similar-looking clumping species such as perennial ryegrass or tall fescue.
Whether the site is residential, commercial, a golf course or an athletic field, edging provides the finishing touch to well-groomed turf. Using the right edger for the job not only saves labor, it makes it possible to achieve the best possible appearance for the turf.
Wallace "Tinker" Clift, C.G.C.S., is a department chair of the golf-course and turfgrass-management program at Texas State Technical College (Waco, Texas).
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