The complete guide
Choosing a Cordless String Trimmer for Lawn Borders
A mower can leave a lawn looking mostly finished while long grass still gathers beside paths, around obstacles and along the boundary. Those small areas can take more attention than their size suggests. A cordless string trimmer gives you another way to reach the grass that needs that final pass.
The BLACK+DECKER LST300 combines grass trimming with wheeled edging. It comes with a battery and charger, so you can compare it as a kit rather than a bare tool. Before buying, it helps to look beyond the cordless label and think about your borders, working posture and charging needs.
What this tool is designed to do
The LST300 is a battery powered grass trimmer for grass, weeds and overgrowth. Its cutting string does the work, with a listed cutting width of 12 inches. You use it for trimming, then change its working position when you want to edge.
That makes it worth considering for the finishing jobs around a lawn. Think about the grass left beside a paved path or the border that looks untidy after mowing. These are different tasks from cutting a whole open lawn, and they call for a different approach.
Do not assume that a string trimmer is also a brush cutter. This record gives no cutting capacity for woody stems or thick scrub. If those are your main problems, establish the right tool type before comparing batteries or prices.
How the cutting system works
The cutting head uses string, which wears as it works. On this model, the Automatic Feed Spool supplies line as needed without requiring you to bump the head against the ground.
That is a useful distinction when comparing an automatic feed trimmer with a bump-feed design. It changes how you manage line during use, though you still need to inspect the spool and follow the manual when replacing it. Automatic feed does not mean the line never needs attention.
The listed speed is 6200 rpm. BLACK+DECKER also specifies its PowerDrive Transmission, which is designed to increase torque at the cutting string. These details describe the tool, but they do not tell you how quickly it will finish every patch of grass. Growth conditions and how you work still matter.
Trimming and edging are different jobs
In trimming mode, the tool cuts grass and weeds. In edging mode, it becomes a wheeled lawn edger for working along the lawn boundary.
Having both functions in one tool can be helpful if your usual garden routine includes both jobs. You do not need to choose between a trimming-only tool and a separate powered edger just to get those two functions.
Still, look closely at the borders you have. A clear lawn-to-path boundary presents a different task from an uneven area filled with stones or roots. Check the manufacturer's operating guidance and inspect the ground before starting. The edging function should not be taken as a promise that it can cut through every surface.
Match the tool to your garden
Start with the work you actually do, rather than the size of the garden alone. A small lawn with many borders may involve more detailed trimming than a larger open lawn with few obstacles.
Walk around your space and note where the mower leaves grass behind. Consider whether those areas need regular light attention or whether you are facing a first clear-up of heavy growth. The LST300 is described for grass, weeds and overgrowth, but no recommended garden area is supplied.
If you are choosing a small garden trimmer, cordless movement and the two working modes may be useful. However, this record does not give runtime. There is no sound basis for promising that one charge will finish your particular garden.
Understand the included battery
The package includes one LBXR2020 20V MAX lithium ion battery with a stated capacity of 2.0 Ah. A charger is included too.
Battery capacity is a useful comparison point, but it is not a runtime promise. Do not turn the 2.0 Ah figure into an assumed number of working minutes. This record gives neither a runtime test nor a charging time.
For your first few sessions, leave room to learn how the tool fits your routine. If you need to finish a large amount of work without stopping, seek confirmed runtime information before buying. That is more useful than relying on a general claim about cordless convenience.
Check battery and charger compatibility
The LST300 belongs to the BLACK+DECKER 20V MAX Powerconnect system. The product information states that the battery can be shared with compatible tools in that system.
If you already own BLACK+DECKER tools, check their exact models and battery requirements. A familiar brand name alone is not enough to establish compatibility. Confirm the system match before counting an existing battery as a spare.
For country-specific orders, also check the charger. Its input voltage and plug type are not specified here. A charger being included does not confirm that it suits every local power supply. Resolve that point before placing the order, especially when comparing listings across countries.
Think about weight and working position
The listed weight is 2.59 kg, with 5.7 pounds shown in the product specifications. Use that figure when comparing handheld garden tools, rather than relying only on the phrase lightweight grass trimmer.
How a tool feels also depends on your reach and working posture. This model has adjustable handle and height positions, allowing you to change its setup. The adjustment range is not provided, so it is worth checking further if you have specific reach needs.
Set the tool up before starting. Follow the manual and make sure the adjustments are secure. Avoid choosing a tool solely because someone else finds it comfortable, since their height, grip and garden layout may differ from yours.
Read the measurements carefully
The 12-inch figure is the cutting width. It is not the tool's overall width and does not describe its storage footprint.
The product details separately list length and width as 36.23 x 8.5 inches. A complete set of length, width and height measurements is not available in this record.
If you plan to store the trimmer in a narrow cupboard or a fixed space in a shed, confirm the dimensions you need before ordering. Do not assume that adjustable height means a particular collapsed length. The listing does not supply that measurement.
This distinction is easy to miss when comparing a 12 inch string trimmer with other models. Cutting size and storage size answer different questions.
Know what arrives in the kit
The listed package contains the LST300 trimmer/edger, one LBXR2020 battery, a charger, an AF-100 spool and a guard. That gives you a clear checklist for comparing this offer with other listings.
A lower-priced listing may be a bare tool, while another may contain a different battery package. Compare the actual contents rather than the model name alone.
The included spool also gives you a starting point for future maintenance. When you need a replacement AF-100 spool, confirm its compatibility with the LST300. Follow the manual for fitting it, and do not assume that line or spools from another trimmer will work just because they look similar.
Build care into your routine
Remove the battery before cleaning, inspecting the head or changing the spool. Clear away grass and debris after use, following the manufacturer's instructions.
Pay attention to the guard, line and fittings before the next session. If something looks worn or damaged, address it before starting. Keep the battery and charger dry, and follow their own instructions for charging and storage.
Store the tool in a dry place away from children. A simple inspection and cleaning habit makes it easier to spot a problem before you are ready to work.
Also follow the manual for protective equipment and safe working distances. Cordless operation removes the trailing power lead, but the cutting head still needs careful handling around people, pets and loose debris.
Check purchase details before deciding
A two-year limited manufacturer warranty is listed. The full terms and regional coverage are not supplied here, so check those details if warranty support is important to your decision.
Delivery lead time is also unspecified. Use the estimate shown for your address rather than assuming a standard arrival date.
Read the returns policy before using the tool outdoors. Rules for opened or used power tools may affect your options if it does not suit your needs. Checking these practical details beforehand can prevent a garden purchase from becoming a difficult return.
The short version
The BLACK+DECKER LST300 brings together a 12-inch cutting width, automatic line feed and wheeled edging in a cordless tool. The included battery, charger, spool and guard make the package contents clear.
It is worth considering for grass trimming and lawn-border work if those functions match your garden. Confirm charger suitability, allow for the unknown runtime, and compare the listed weight with your handling needs. Those checks matter more than choosing on a headline alone.