Black + Decker LST300 review

Lightweight and versatile, the Black + Decker LST300 weed trimmer is a great option for smaller jobs.

Image shows the Black + Decker LST300.
(Image: © Mike Larson.)

Top Ten Reviews Verdict

The Black + Decker LST300 weed trimmer and edger is a fine choice for light to medium duty work.


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    Easy to setup

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    Battery system interchangeable with other products


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    Line can be inconsistent

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    Mostly made of plastic

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Originally known as a maker of power tools, Black + Decker has also become a big name in the string trimmers, particularly models at lower price points. We recently reviewed the Black + Decker LST300 electric cordless 12-inch trimmer. 

Black + Decker LST300: Key specs

Type: Cordless electric

Motor: 6,200 RPM

Battery life: 25-30 min

Dimensions: 47 in. long (35 in. when collapsed)

Weight: 5.7 lbs

Cutting width: 12 in

Warranty: 2 years (limited)

Retailing between $80 and $100, we found the trimmer to be a very affordable option for light to medium duty work, and great for smaller yards and fence lines. It’s easy to set up and simple to use and has respectable battery life. Branded as a trimmer and an edger, we found it’s a bit more effective at trimming, but still able to hold its own as an edger.

It’s relatively quiet, and, at under 6 lbs, it’s light enough to carry around the yard for long periods of time without any discomfort. For a battery-powered trimmer, it has decent strength (particularly with a battery right off the charger), however, for really thick weeds and grasses, the LST300 does struggle a bit.

The mostly plastic construction also feeds fears that it might easily break or crack if dropped. However, there is plenty that we like about this trimmer. A pivoting handle gives the user some flexibility in the way they can hold it and its adjustable length capability does give it some versatility. Read on to find out whether the Black + Decker LST300 is the right electric string trimmer for you!

Black + Decker LST300: Design

There is nothing avant-garde about the design of the Black + Decker LST300; for all intents and purposes, it’s a pretty standard trimmer. It’s got a coated and ergonomic handle near the ignition trigger and an adjustable handler further down, combining for a comfortable hold. Even after we used the trimmer for close to 30 minutes, it was still easy and comfortable to use.

The trimmer only comes in one color scheme: Black + Decker’s signature orange and black (with a gray motor housing and a stainless steel adjustable neck). It’s a striking color combination and really does look good.

Most of the trimmer is made of plastic, which looks great out of the box, however, it is a material that’s prone to cracking and breaking if dropped or knocked over. One feature we really loved was the adjustable neck, which allows the user to make the trimmer longer or shorter, adding to its versatility.

Image shows the Black + Decker LST300.

(Image credit: Mike Larson.)

Black + Decker LST300: Features

When it comes to features, the LST300 is kind of a “what-you-see-is-what-you-get” tool. It has one speed, along with the adjustable handle and neck that we’ve already touched on.  

It does feature a 0.065-inch line, fed by Black + Decker’s AFS (automatic feed spool) system. The system is supposed to feel the line out to the perfect length automatically and touts itself as “no bumping required.” However, there were a few times we had to stop to pull the line out manually when it frayed or broke off. The head on the trimmer can also rotate 90 degrees so it can be used as an edger. 

Image shows the Black + Decker LST300.

(Image credit: Mike Larson.)

The string spool is quick and easy to change and the auto-feed functionality means you won’t need to keep making adjustments as you cut. The supplied string does struggle with heavier weeds, but by swapping it out for an edged string you should be able to achieve better results on stubborn overgrowth.

While the convenience of a battery-powered lawn trimmer means you forgo some of the power of a gas trimmer, the Black + Decker LST300 has been designed to get the most out of its battery power. The 20-volt battery lasts for about 25 minutes of trimming and Black and Decker has utilized its own PowerDrive transmission in order to deliver more power from the motor to the cutting string, helping you cut your lawn quicker.

Another benefit of electric weed eaters is that they’re quieter and light, and the Black + Decker LST300 is no exception. At just under 6 lbs it’s one of the lightest electric weed eaters we’ve reviewed, only slightly heavier than the Sun Joe TRJ13STE Electric Weed Eater, which weighs in at 5 lbs. 

Image shows the Black + Decker LST300.

(Image credit: Mike Larson.)

Black + Decker LST300: Setup and assembly

Setup of the Black + Decker LST300 is one of the easiest we’ve encountered. Out of the recyclable cardboard box, it’s just about ready to go. The adjustable handle and string guard are the only things that need to be attached. 

The included instructions were very clear and we were ready to go to work in less than five minutes. The model includes one 20 Max V lithium-ion battery and a sleek charger. The battery was ready to go right out of the box, but we chose to put it on the charger to ensure a full and proper charge before using the trimmer. It took about 35 minutes for the battery to charge fully.

Image shows the Black + Decker LST300.

(Image credit: Mike Larson.)

Black + Decker LST300: Performance

Right off of the charger, the Black + Decker LST300 comes out roaring, but as we used it for an extended period, it did start to lose some of its bite. However, what it loses in battery power, it makes up for in cordless versatility, low noise and no gas-burning exhaust. 

We found the LST300 does great work on regular grass and even high weeds. Where it tends to slip up is on thicker vegetation (think nettles, overgrown crabgrass and bigger patches of dandelion weeds). The trimmer can take these down, we just found it took a little more effort to really get the thicker stuff. The trimmer can also rotate its head to become an edger, which is a nice feature and, while we thought it was better as a trimmer, the edging capabilities are serviceable.

Image shows the Black + Decker LST300.

(Image credit: Mike Larson.)

Black + Decker LST300: Care and maintenance

Like any battery powered electric yard tool, the Black + Decker LST300 should be stored indoors, preferably in a cool, dry place. Storage of this trimmer is made easier by the fact it can collapse down from 47 inches long to just 35 inches. The handle can also fold up, making it easier to hang on a garage or basement wall.

We found cleaning this unit to be relatively easy. The only part that really gets dirty is the line shield, which can easily be removed and cleaned with a hose and a soft brush or a pressure washer.

Black + Decker LST300: Price and availability

At this price point, the Black + Decker LST300 sits near the middle of the road for similar trimmers. It’s comparable in price to other similarly specced models from Ryobi and Kobalt. 

Overall, models at this price tend to have similar features, and the LST300 doesn’t really stand out. If you’re looking for a 20-24V weed trimmer, this unit sits at a reasonable price. However, if you’re willing to spend $50-$100 more, several brands from all over the spectrum (Milwaukee, Makita, Skil, etc.)  offer 40V trimmers that will provide a bit more umph.

The Black + Decker LST300 is available at Home Depot, Walmart and

Black + Decker LST300: User reviews

At the time of writing, the Black + Decker LST300 is pretty well reviewed on Amazon. It’s got a 4.5 rating out of 4,884 global ratings, with 71% 5-star reviews. 

Positive reviews praised the lightness and ease of use of this string trimmer, as well as the possibility of converting it into a lawn edger, with one user saying "I had a 2-stroke weed whacker for years, and while it murdered weeds with impunity, I felt like I spent more time fixing/adjusting it than actually whacking weeds. his little electric trimmer fixed all that. It's about 3x lighter than the engine version, the handle adjusts to your height/angle preference, the head can be turned 90 degrees to get edges, and the lithium battery can run at full tilt for an hour plus, easily."

Some customers had issues with the spools coming undone or being tricky to replace, which affected performance on heavier-duty jobs. 

Should you buy the Black + Decker LST300?

Should you buy the Black + Decker LST300? The short answer is it depends. For small and medium jobs, like trimming around your house and fence or edging the sidewalk in front of your house, the Black + Decker LST300 is an affordable and reasonable choice; we think it’s totally worth the money for this type of use.

However, if you are looking for a beast of a trimmer that isn’t going to be slowed down by thicker weeds and vegetation, you might want to look into a trimmer at a higher price point.

TTR Contributor, Yard Tools
With contributions from