Lawn care, answered

Under 4,000 square feet, a 16–17 inch deck. From 4,000 to about 20,000 square feet — most suburban lots — a 20–21 inch deck. Over three quarters of an acre, a walk-behind is the wrong category. Then measure your narrowest gate, because a 21-inch mower needs roughly 24 inches of clearance. The arithmetic is in the best lawn mower for a large yard.

Electric, for any lawn up to about half an acre: no oil changes, no filters, no spark plugs, no winterizing, and it starts on a trigger every time. Gas still wins past half an acre, because a tank refills in two minutes and a battery takes an hour. The full comparison is in electric vs gas lawn mower.

On any lawn with a real slope, yes — it is the upgrade almost nobody regrets. On genuinely flat ground it adds weight and cost for little benefit, and a push mower of the same deck width is lighter and cheaper. Think of it as a gradient decision rather than a strength one. See best self-propelled lawn mower.

On a lawn inside the machine’s rated area, with navigation that suits your tree cover, yes — mowing stops being a task. Outside those two conditions they disappoint, and it is nearly always a sizing or site mismatch rather than a faulty product. RTK models need a clear sky view; LiDAR and vision models work under canopy. See best robot lawn mower.

Across much of the United States it is the best cool-season choice: it holds color through heat that fades Kentucky bluegrass, roots deeply enough to ride out a dry August, and takes more shade than bluegrass or ryegrass. Buy a turf-type blend rather than Kentucky 31. Full guide: tall fescue.

Both are tall fescue, but Kentucky 31 is a forage cultivar bred for grazing: wide coarse blades and a strong tendency to clump. Turf-type tall fescues were bred for fine blades, density and color. K31 sits next to the good bags at a third of the price and the difference in the finished lawn is permanent. See best fescue grass seed.

Published rates for turf-type tall fescue are typically around 6–8 lb per 1,000 square feet for a new lawn, and roughly half that for overseeding. Always follow the bag, and remember coated seed weighs more per viable seed so it covers less ground per pound than uncoated seed does.

A fine fescue mixture — creeping red, chewings or hard fescue. They are the most shade-tolerant cool-season turf grasses there are, and a different group from tall fescue despite the shared name. Buying more sun seed for a shaded patch never works, because the grass is short of light, not seed. See best grass seed for shade.

Percentages by weight of nitrogen, phosphorus and potassium. Nitrogen drives leaf growth and color, phosphorus matters mostly at establishment, potassium helps stress tolerance. Divide 100 by the first number to get the pounds of product needed per 1,000 square feet for a one-pound nitrogen feed — a 16-4-8 needs about 6.25 lb. Worked through in your lawn fertilizer schedule.

For a cool-season lawn, autumn above all — that is when the grass builds roots and stores carbohydrate rather than pushing leaf, so one September feed does more for next summer than a spring one. Spring is a useful second feed. In high summer prefer iron over nitrogen. See best lawn fertilizer.

On broadleaf weeds spread across the whole lawn, yes. If your weeds are in patches, spot-spraying and feeding separately works better and uses a fraction of the herbicide. There is also a built-in timing conflict: the herbicide wants damp foliage, the fertilizer wants watering in. The autumn application is the one that genuinely does both jobs well — see best weed and feed.

Uneven application. Fix it by applying half the rate in one direction and half at right angles to it, which cancels most of the unevenness any spreader leaves. A spreader with edge control also keeps product out of beds and off paving. See best broadcast spreader.

Aerating fixes the soil: it removes plugs of earth to create air space in compacted ground. Dethatching removes a layer of dead stems sitting above the soil that is shedding water. Two different problems, two different tools — and two simple tests tell you which you have, in aerating vs dethatching.

Core, clearly, if the problem is compaction: it pulls plugs of soil out and leaves real air space. A spike pushes soil sideways and compresses the walls of the hole. Spike aerators are genuinely useful for slicing a seedbed before overseeding, and not much else. See best lawn aerator.

CFM. It measures the volume of air moved, and volume is what carries a leaf pile across a lawn. MPH is nozzle speed, which helps unstick wet leaf from grass. A blower with high MPH and low CFM feels powerful and moves very little. If a maker publishes only MPH, treat that absence as informative — see best leaf blower.

For occasional work, yes — many trimmers rotate to cut vertically. But the cutting depth is then set by your arm, which gives a scalloped wandering line. A wheeled edger with a depth stop cuts the same depth the whole way, which is what makes an edge look crisp. See best lawn edger.

No — that is a persistent myth, and it costs people a lot of unnecessary bagging. Clippings are mostly water and break down quickly. Thatch comes from stems, crowns and roots accumulating faster than soil life can process them, which excess nitrogen and compaction both encourage.

Higher than most people do. Taller grass shades its own soil, keeps roots cooler, holds moisture longer and crowds out weed seedlings that need light to germinate. Raising the deck is the cheapest lawn improvement available — and scalping a lawn short in July is the most common self-inflicted lawn injury there is.

No, and we say so on every page. We do not have a test lawn, and we have not mowed with these machines, sown these seeds or spread these fertilizers. What we do is compile the published specifications and seed labels, do the deck-width and pounds-of-nitrogen math, and cite the people who have measured things — then rank on that. Our full method is on how we pick.

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