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Greenworks 21212 4 Amp 13 Inch Corded String Trimmer Review

Greenworks 21212 4 Amp 13 Inch Corded String Trimmer ReviewScore 91%Score 91%

Greenworks 21212 4 Amp 13 Inch
Corded String Trimmer Review

Review At A Glance

You’ve got to go some to find a better budget, lightweight weed eater than the Greenworks 21212 4 Amp 13 Inch Corded String Trimmer.

  • Design 87% 87%
  • Performance 88% 88%
  • Price 98% 98%
  • Overall 91% 91%

Check The Price

To get the latest price for the Greenworks 21212 click on the image above.



Power – Electric


Dimensions (w x h x d in inches) – 4.3 x 39.5 x 10


Cutting Width – 13 inches


Line Diameter – 0.065 inches


Feed System – Dual Auto Feed


Model – 21212


Amps – 4


Voltage – 120


Weight – 5.2lbs


Four Year Warranty


About The Greenworks 21212 String Trimmer

The Greenworks 21212 is a budget end electric string trimmer. It has a 13 inch cutting swath and a dual feed automatic 0.065 inch line.

Casting a closer eye on it:

It has a telescopic shaft you can adjust according to your height and the handle rotates 180 degrees if you want to edge. It has a 4 amp motor you start by holding a trigger and comes with a four year warranty.

The power cord is not included. Make sure you use a good quality outdoor extension cord that is heavy enough to carry the current your product will draw.

An AWG size of at least 16 gauge is recommended for an extension cord of 50 feet or less in length. Extension cords over 100 feet are not recommended.

It is worth remembering that.

There is also a strain release cord you should feed the extension cord around which helps ensure the extension cord does not disconnect.

To use the auto string feed feature run the trimmer by holding the trigger, then release the trigger so it stops. Wait two seconds and then press the trigger again and the strings will automatically advance.

You can advance the strings manually by turning the machine off and disconnecting the trimmer and pushing in the spool retainer button, then pulling on the strings and pull them out.

And finally:

It weighs in at 5.2lbs.

The Good

First things first:

The price of the Greenwork 21212 is truly phenomenal. It is right at the bottom end of the string trimmer price market, but it doesn’t perform that way as you will see.

It is really light too. Of my three favourite weed eaters – the Black and Decker GH900 and the Toro 51480 – being the other two, it is the lightest of the lot.

So what does this mean for you?

It means that for older people or people with limited mobility it is a great choice as it doesn’t fatigue you.


Above: This Greenworks has an automatic line feed that workds well.

For the price and weight it is nice and powerful. A squeeze of the trigger to get it started and it can handle lots without missing a beat – foot long weeds, thick pond lillies, overgrown grass – anything like that is a not a problem.

Now I am not suggesting it can deal with everything.

As it does strain if you encounter really thick brush or weeds, but overall the 4 amp engine gives you more power than it really should – certainly more power than the price tag indicates.

This has a dual automatic line feed and it works well. Release the trigger for two seconds and the line will automatically advance for two seconds. It is quite economical on string and the line feed is reliable and simple to use.

And you know what surprised me?

For a budget price trimmer it has several unexpected features. The shaft length can be easily adjusted to suit your height.

There is a catch built into the handle which safely secures the extension cord to stop it being easily detached and this works well.

Above: The shaft length can be easily adjusted

The head can also be quickly and easily rotated 180 degrees. Simply pull the little sleeve on the shaft to unlock the cutting head and then just swivel it depending upon how you want to use – as a trimmer or an edger. 

It couldn’t be much easier.

For the price you pay you should get a decent amount of use out of this. I like the fact that it is a double string as this reduces stress on the head during use.

This is turns contributes to the longevity of the device as it means the ball bearings are not unduly aged. There is a fair amount of plastic in the build, but it is sturdy and durable.

And get this:

You get a four year warranty – amazing for a budget trimmer!

The Not So Good

There are a few issues around the handle. Mainly the trigger is quite large, taking up pretty much the whole handle and there is no safety lock.


This means it is easy to grab it and inadvertently start it up and rip through something without realising. I am surprised this feature hasn’t been added.

Also the handle is slightly flimsy and has a tendency to move a little whilst you use it. It isn’t a major thing, but it is definitely noticeable.

You might want to note this:

Despite the shaft being adjustable, even at its longest it is not very long and if you are above 6 foot you will find yourself stooping somewhat.

Generally most people who buy this will have smaller yards, so won’t take too long trimming, so it shouldn’t be a massive problem. Just be aware you might be left with a slightly sore back or arms after use if you are tall.

Beyond that:

The plug placement is slightly awkward, it protrudes from the head of the unit and it is easy to bump it with your leg or hip. Thankfully the cord should be well secured due to the cord retention grip.

Finally this is a lightweight, budget trimmer if you have lots of thick bush or a large yard to trim it is not for you.

Above: The Greenworks 21212 is slightly short even when the shaft is extended fully.

At A Glance



Great Price


Very lightweight


Good amount of power


Auto line feed is easy to work


Adjustable handle


Cord is secured well


180 degree head rotation


Should last a while


Four year warranty



No safety lock


Handles moves


Short even at longest length


Plug placement is annoying


Not for large scale jobs


Does this take a two-prong or three-prong extension cord?
It takes a two prong.
Do I have to use the prestrung spools? Or can I buy my own string for it?
You can purchase your own line, just make sure it is the correct diameter (0.065 inches) so it fits through the holes.
Is this a brushed or brushless motor?
It has a brushed motor.
If I pull the trigger harder does the speed increase?
No it is a simple turn on and off switch. There is no variable speed.

You Might Also Like…

There are a number of top quality weed eaters around these days, my favourite is the Ego Power String Trimmer – it is battery powered, but it is great!

In terms of electric powered weed trimmers, you might want to check out the Black & Decker GH900. To the right are a list of general resources that maybe be of use.

You can also view my Site Index, which shows everything on my site on one page or use my recommended links below.

Recommended Links


Review Date
Reviewed Item
Greenworks 21212 4 Amp 13 Inch Corded String Trimmer
Author Rating

My Verdict


Summary I will preface my conclusion by saying if you have a larger yard, or medium to high level work that needs to be done, then this definitely isn’t for you.

But having said that for simple, straightforward, smaller jobs it is unbeatable and I can almost guarantee you won’t find a better budget trimmer that this one.

It is light, quiet, easy to use, will easily hack through tall grass, brambles, larger weeds and has a good amount of power to do so. It might actually be the case you look at the price and think it is too good to be true, well it isn’t I promise you!

Want a budget price, lightweight, powerful, durable, electric weed eater - this should be your top choice!



About The Author

Steve Mann

Steve is a one time gardening hater turned into gardening obsessive. This was all thanks to going to University where a two year stint spent transforming the previously horrific garden of the student house he lived in left him addicted to all things horticultural! Now with a new house in tow and due to some fortunate circumstances he is free to test out a whole host of gardening equipment. Find out more about Steve or drop him an email at


  1. Jennifer

    This trimmer looks like something I might like. I like that it is electric and I don’t have to mess with mixing gas and oil. What I really like it that it is so light weight, I really don’t like weed-eating and trimming my yard but I don’t want to spray it. I do not like that there is no safety lock so I wouldn’t be able to let my son use it until he is much older. But overall, I would definitely consider this trimmer when I go to purchase again.

    • Steve Mann

      Thanks Jennifer, if you have a smaller yard and are after a lightweight trimmer at a bargain price then this is an excellent option. Best wait until your son is older before letting him use it though as you say!

  2. 1deveraux

    I want one of these for my garden, I’m really happy with the description and detail you’ve given and notice you mention need to buy the extension cable separately, does it have a normal mains cable, if so what length is it?

    Can I purchase here and how long is shipping? Thanks

    • Steve Mann

      Thank you! Glad you like my review. It has no cable at all, you need to buy an extension cord separately. You will be looking at a 16 gauge extensions cord for 50 feet or less. Cords over 100 feet are not recommended. Any of my links here should take you to Amazon where you will get the best price for this trimmer.

      Hope you like it!


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