Cool-season grasses — fescues, ryegrasses, Kentucky bluegrass — have a survival strategy that looks exactly like failure. When it gets hot and dry enough, they stop trying. Growth halts, the blades go straw-coloured, and the plant puts what it has into keeping the crown alive underground until conditions improve.
The lawn looks dead. It is not. And the reason this particular confusion is worth a page of its own is that the wrong response is actively harmful in both directions: reseeding a dormant lawn wastes seed on ground that already has living grass in it, and waiting patiently for a dead lawn to recover costs you the entire rest of the season.
Why you cannot tell from the colour
You cannot, and neither can a photograph. Dormant grass and dead grass are the same straw-brown, in the same irregular spread, in the same weather. Anyone who tells you which one it is from a picture taken at standing height is guessing.
What separates them is not visible until you get a single plant out of the ground.
Pull one plant and look at the crown — the short pale section where the blades meet the roots, at soil level.
Firm, and white or cream: dormant. That plant is alive and waiting.
Brown, dry, and crumbling between your fingers: dead.
Do this in five or six spots across the patch, not one. A lawn is rarely all one or all the other, and what you usually find is a mix — which is itself the answer, because it tells you the lawn will come back thin and will want overseeding rather than a full reseed.
There is a second test that costs nothing but takes two weeks: water a small marked area deeply and watch it. Dormant grass in a watered patch greens up within about ten to fourteen days once the heat breaks. Dead grass stays exactly as it is.
The tug test tells you something different
If you have read about pulling turf to check for grubs, note that this is not the same test and it does not answer this question.
Turf that lifts away in a sheet has had its roots eaten — that is a grub problem, and it can happen to a lawn that is otherwise perfectly healthy. Dormant grass stays rooted. Dead-from-drought grass also usually stays rooted, at least at first. So the tug tells you whether something ate the roots; the crown tells you whether the plant is alive. Two questions, two tests.
How long dormancy is safe
Cool-season grass can hold in dormancy for roughly four to six weeks without serious loss. Past that, crowns start dying in earnest, and a lawn that went into a drought looking uniform comes out of it patchy.
That is the argument for the small amount of water rather than none at all. About 1.5 cm every fortnight will not green the lawn up and is not meant to — it keeps the crowns hydrated enough to survive until the weather does the rest.
What not to do while it is dormant
Do not fertilize. This is the one that kills lawns. A dormant plant is not growing and cannot use nitrogen; what it gets instead is salt in dry soil around a stressed crown. Feeding a lawn to bring it out of dormancy is one of the more reliable ways to turn a recoverable lawn into a dead one.
Keep traffic off it. Dormant crowns are brittle, and a path worn across a dormant lawn in August is still visible the following spring.
Do not mow it short. If it needs cutting at all, cut high. There is no growth to remove and every blade left standing is shading its own crown.
If the crowns are dead
Then it is a reseeding job, and the useful question becomes why — because the same conditions will still be there in a year. Grass that died in place, with roots intact and no insect underneath, was short of water in soil that could not hold it: often compaction, often a thin layer over builder’s rubble, sometimes simply a slope that sheds everything you put on it. Reseeding without dealing with that produces the same brown patch next July, in the same outline.
Colour tells you nothing here, and neither does a photograph. Pull a single plant and look at the crown where the blades meet the roots: firm and white means dormant and alive, brown and crumbling means dead. Check five or six spots, because most lawns are a mixture.
While it is dormant: do not fertilize, keep traffic off it, and give it about 1.5 cm of water a fortnight — enough to keep the crowns alive, not enough to force growth. And if the crowns are dead, work out why the water ran out before you reseed into the same conditions.