Make sure your trimmer suits you


May 10, 2007




Call it what you want - a weed-whacker, weed-eater or string trimmer. It's weed season and time to know what trimmer will work best for you. I'll review the positive and negative aspects of each type, highlight some accessories and include a list of some safety tips, hoping to make your gardening experience a little easier and safer.



An aisle of weed trimming equipment can be found at most larger garden centers.




Electric trimmers are either powered by a 12-volt battery or require an extension cord. Battery trimmers usually last for 45 minutes or so and start losing cutting power as the battery runs down. The batteries typically take 24 hours to completely recharge. These trimmers weigh approximately 10 pounds, have an 8- or 12-inch cutting width, and are most useful for yards needing only a modest amount of trimming.


Extension cord models are powerful enough for most lawn care and can also be used as an edger for curbs, sidewalks and driveways. Motor sizes run from 1.8 to 6 amps, weigh from 3.2 to 8.5 pounds and have a cutting width from 9 to 15 inches. The down side, of course, is that manufacturers recommend using an extension cord no longer than 100 feet, so it's not much use in the "north 40."


Even with a smaller yard and a sufficient number of electrical outlets, that's a lot of extension cord to haul around, as well as the problems of the cord getting tangled, dragging through flower beds, and hung up on or under something. On the other hand, electric trimmers are easy to start, usually weigh less than gas models and require minimal maintenance other than cleaning the heads and replacing the trimmer string.


Gas Trimmers


Most home-style gas trimmers have engines ranging in size from 21.2 cc to 25.4 cc, weigh from 9 to 14 pounds and have cutting widths from 16 to 18 inches. Generally, the larger the engine, the heavier it is.


Except for heavy-duty, four-cycle commercial models, gas-powered trimmers have two-cycle engines and that means an oil/gasoline mixture for fuel. The correct type of oil is available at most lawn and garden centers and comes in small containers with just the right amount of oil to mix with a gallon of gasoline. I strongly recommend that the mixed fuel for two-cycle engines, including edgers, leaf blowers and chainsaws, be kept in a differently colored or smaller, clearly marked container so that some well-meaning soul doesn't use the one for your lawn mower that could damage your trimmer.


Gas trimmers are available with either a curved or straight shaft. If you have to trim under shrubs or hedges, a straight shaft is easier to use and less likely to break branches. It also seems easier to use as an edger; however, a curved shaft, to me at least, feels as if it's better balanced.


String Replacement


Trimmer string (line or cord) for non-commercial models comes in diameters from 0.065 to 0.095 inches. Check the owner's manual for the correct size for your model; using a size larger than recommended will wear out the motor or engine sooner. A number of popular brands sell pre-loaded spools, making replacement easy but relatively expensive. Alternatively, you can reload the spool by hand using line bought in bulk packages (approximately 300 or 900 feet long) much cheaper by the foot.


Most trimmers have a "bump head" containing the string pool. Tapping the head on the ground while the head is turning automatically extends more cord from the spool. I suggest reloading "bump head" trimmers in an empty room with a bare floor so that you can see it if the spring under the head cover flies off. I bought three replacement springs at once last year and spray-painted them a bright yellow. Since I didn't have an empty room available, I still lost two of them before the season was over.




Various accessories are available for gas trimmers (electric ones usually don't have any). The best one to buy first is a padded shoulder strap. It can prevent sore muscles and makes it easier to balance the trimmer. Some trimmer brands have an optional connector halfway down the shaft. The lower part of the shaft can be replaced with several types of attachments, including a light brush cutter, an edger and even a small tiller. There are several brands of universal attachments for most popular trimmers. It's cheaper, of course, to buy a variety of attachments rather than separate tools. Keep in mind, though, if the engine goes out in the middle of the yard chores, you now have two or three useless tools instead of just one.


There are several brands of a great accessory that replaces the "bump head" on some trimmers. This type of head has a number of small openings around its perimeter. A 12-inch, pre-cut piece of line cord is inserted into each opening until it emerges into a hole in the center of the head. The cords are held in place by one-way clamps. When the pieces wear down close to the head, the remnants are pulled out through the center opening for replacement by new pieces. Pre-cut pieces, available in bags of 50, are rather pricey. You can buy a bulk roll, and in an hour or so of watching television, easily cut enough pieces to last the season.




All trimmer heads should be cleaned after each use (with the motor or engine off). Clean or replace the sparkplug on gas models at the end of each season and read the owners manual thoroughly for other maintenance requirements. Many brands come with a one or two year manufacturer's warranty. Various retailers offer extended warranties, but in my estimation, are seldom worth it.


Finally, before buying a trimmer, do some homework on what will work best for you, including checking with your friends and neighbors. Some brands last longer and some, importantly, are much easier to start.


The Gardeners' Dirt is written by members of the Victoria County Master Gardener Association, an educational outreach of Texas Cooperative Extension-Victoria County. Mail your questions in care of the Advocate, P.O. Box 1518, Victoria, Texas 77901; or, or comment on this column at