The New Costco Mower Worth Buying, According To Reviews

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If you already believe certain Costco finds are always worth buying, you may want to take a look at the Greenworks 80-volt, 21-inch poly deck self-propelled mower, new to Costco. It seems to be the first Greenworks mower with a steel-reinforced poly deck, made of a lightweight polymer instead of a stamped steel deck. This makes it lighter and less expensive than similar models, like Greenworks' earlier Gen 2 version of the 21-inch mower. It's so new at Costco that it only has a handful of ratings. 

Of five people rating it so far, the new mower has a cumulative 4 out of 5 stars. The reviewer that gave it 1 star liked the mower, but had issues with the batteries. This mower isn't labeled as a Costco exclusive, but so far, there's no mention of this model on the manufacturer's website or at other retailers. At Costco, the Greenworks mower lists for $630, but was on sale for $530 at publication time. It's available at some warehouse locations and through Costco online (shipping included).

This push mower includes two batteries (2ah and 4ah), with onboard ports for both the active and the stored battery. The 4-in-1 mower, with options for side discharge, rear bagging, mulching, and even for picking up leaves. The mower also folds up for vertical storage and has LED lights for operating when a little extra light is needed.

It may be worth noting that a comparable (but slightly different) Greenworks mower sold at Best Buy has a cumulative 4.5 stars from 654 total users ranking it, so it's possible that the Costco version will rank similarly over time. Best Buy's 21-inch Greenworks mower is currently on sale for $479, but only comes with one battery.

The new Greenworks mower at Costco features eight height settings easily activated with one hand, (the similar Best Buy model has seven settings, using a classic lever adjustment). With 8-inch front wheels and 10-inch rear wheels, this mower could be handy on bumpy, uneven terrain, since large rear wheels improve a walk-behind mower's traction. Having two onboard batteries allows for extra mowing time, although you'll need to manually switch the fresh battery over to the active port. The product page claims a runtime of 65 minutes on a charge, and that the mower can cut up to a half-acre on a single charge, though it doesn't specify whether that means using both batteries.

The four positive reviews so far emphasize that there is plenty of battery power to cover the purchasers' yards. "I have a fairly big back yard and I haven't exhausted both batteries while mowing my very dense, overgrown lawn," says reviewer Holiday75. The same reviewer says it takes just over 30 minutes to charge the 2ah battery, and over an hour to charge the 4ah battery.

Reviewers also praise the mower's ease of set-up, powerful motor, and the mulch bag capacity. "It took 5 minutes to get it running, " says reviewer DieterQ, who was skeptical after owning a gas-powered Toro, "and I cut my whole yard with a 1/2-charged battery straight out of the box (yes, I probably should have charged it before use)."

Beyond the battery issues for one Costco reviewer, Redditor Bob_Chris noted at subreddit r/Greenworks that, while inspecting the mower in person, they found it too flimsy, compared with the previous model, due to the "plastic" deck. However, elsewhere on Reddit, posters note that poly decks are lighter and significantly easier to manuever compared with steel.

Based on user reviews, price, and features, the Greenworks 21-inch poly deck self-propelled mower sold at Costco could be a worthwhile purchase, especially when on sale. It's too new, it seems, to have garnered reviews on YouTube or lawncare blogs. 

Prices for other 80-volt Greenworks mowers with the same deck size (but in stamped steel rather than a poly deck) start at $540 on the manufacturer's website, and that's for a refurbished model with a single battery. A similar, sold-out Greenworks mower with a steel deck (instead of poly) sold for about $1,000.

The poly deck generally makes the mower lighter and less expensive than similar models with steel decks, though Costco's product listing doesn't give specifics about the mower weight minus the batteries. If you feel a steel deck is superior, this may not be the mower for you, but if you're looking for a good price, the poly is worth checking out. You may want to inspect this model in person at a Costco before you buy.

As a bonus, the Greenworks 80-volt battery fits more than 75 different tool from the manufacturer, according to the product information. It's worth noting that Greenworks makes some of the top-rated lawnmowers sold at Costco, so consider the new poly deck model if you're looking for an electric self-propelled mower.