How often should you fertilize your lawn?

Why bother

Feeds the lawn so weeds get less room. A thorough-tier job. Skippable when life's busy, worth it when it isn't.

What the job involves

1. Feed it on the lawn's schedule, not yours. Cool-season grass (fescue, bluegrass, ryegrass) gets the big feed in fall and a lighter one in spring. Warm-season grass (Bermuda, Zoysia, St. Augustine) wants it through late spring and summer, when it's actually growing.
2. Read the N-P-K numbers on the bag and set the spreader to match. The one rule worth remembering: no more than 1 lb of nitrogen per 1,000 sq ft in a single go. More is not better, it just burns the grass.
3. Spread it even, in slightly overlapping passes. Skip a strip and you get pale patches; double up and you get scorched ones. Both look daft for weeks.
4. Water it in lightly afterwards so it reaches the roots, unless the bag says otherwise. Sweep the stray granules off the drive and path too, or the next rain washes your fertilizer into the storm drain instead of the lawn.

Do it yourself, or pay someone?

Yourself, easily. A bag runs $15 to $40 and covers a few thousand square feet, the spreader's a one-time $50 to $150, so a full year of feeding costs less than a single pro visit. A pro charges $77 to $395 an application, around $225 on average; worth it only for a big lawn, or if you want weed control bundled in.

What skipping it costs

$300 to $1,350 to reseed a lawn that's thinned out, and $2,000 to $5,200 to re-sod a typical 2,000 sq ft yard if it goes past saving. Skipping the feed isn't a one-day disaster, it's a slow fade: the grass goes pale and sparse, weeds move into the gaps the turf should be choking out, and eventually you're not feeding a lawn, you're rebuilding one. Reseeding the thin patches runs $300 to $1,350; full replacement with sod runs roughly a dollar to two-and-a-half a square foot installed. A DIY feed costs well under $100 a year. The math isn't subtle.

Signs it's overdue

• The grass is pale, yellow-green, or thin, and slow to fill back in where it gets mown short or walked on. That's a hungry, nitrogen-starved lawn.
• Weeds are winning. Crabgrass, clover, and dandelions are spreading into the bare and sparse patches the grass should be crowding out.
• You can't remember the last time you fed it, it's been a year or more, and the lawn looks tired next to the neighbors'.

When to start thinking about it

Give yourself about 7 days' notice. That's when Grumpty starts grumbling, so it doesn't land on you the day it's due. Mark it done and Grumpty sets the next one, every 6 months, so you can go back to forgetting it exists.

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