Should I lay turf or sow grass seed?

What each option really costs in money, time and risk, and the situations where one of them is clearly the wrong answer.

Difficulty: beginner
Time: 30 min
Read: 3 min

Short answer

Turf gives an instant lawn for roughly five to ten times the material cost and needs daily watering for a month. Seed is cheap and gives a better-matched lawn but takes a season to be usable and only works in two narrow sowing windows. On a slope or where you need to use the lawn soon, turf; almost everywhere else, seed.

Both need identical ground preparation, and that preparation is most of the work in either case. Choosing between them is a decision about time and risk, not about effort.

Step by step

Work out when you need to use it.Turf can take light traffic in three to four weeks and normal use after a couple of months. Seed needs a full growing season before it takes children and football.
Check the season.Turf can be laid any time the ground is workable and not frozen or baked, so autumn through spring. Seed only sows successfully in about April to May and September.
Compare the real costs.Seed is a few pounds per square metre of prepared ground; turf is several times that before delivery. But turf also commits you to a month of daily watering, which has a cost in a metered household.
Consider the slope.Seed washes off any noticeable slope in the first heavy rain. Turf pegged down holds. This alone decides many gardens.
Consider matching an existing lawn.Overseeding an existing lawn with a similar seed mixture blends invisibly. A strip of turf beside an old lawn shows as a different colour and texture for years.
Prepare the ground identically for both.Clear weeds, dig or rotavate, remove stones, level, firm by treading, and rake to a fine tilth. Both fail on poor preparation.
Buy turf to lay the same day.Rolled turf heats up and yellows within about 24 hours in summer. Order for a day you can lay it, not a day it is convenient to be delivered.
Plan the watering.New turf needs enough water to reach through the turf into the soil below every day for the first three to four weeks. New seed needs light watering twice daily until germination.

Tips

The ground preparation is the same for both and is most of the work.
Seed on a slope washes into the bottom corner in the first storm.
Turf that has sat rolled up for two days in summer is already damaged.

Common mistakes

Laying turf and watering it lightly — Light watering wets the turf but not the soil below, so roots stay in the turf layer and it shrinks and gaps. The water has to go through into the soil.
Sowing seed in midsummer — Germination needs constant surface moisture for weeks. In July that is close to impossible without a sprinkler running twice a day.

If it doesn't work

Turf shrinking with gaps between rolls

Cause: Not watered deeply enough — Fix: Water heavily, brush a sandy topdressing into the gaps and keep it damp.

Seed washed into drifts

Cause: Sown on a slope or watered too hard — Fix: Rake level and overseed the bare areas, watering as a fine mist.

New lawn full of weeds

Cause: Ground not cleared of perennial weed roots first — Fix: Spot treat or dig out. Perennial roots left in the ground come back through both turf and seed.

New turf yellowing

Cause: Laid late after delivery, or drying out — Fix: Water thoroughly. Turf that yellowed from heat in the roll usually greens up if it is not also dry.

Questions people ask

Is turf worth the extra cost?

If you need a usable lawn quickly, if the ground slopes, or if you are outside the two seed-sowing windows, yes. Otherwise seed produces an equally good lawn for a fraction of the price.

How long before I can walk on a new lawn?

Turf, around three to four weeks for light use. Seed, after two or three mowings — realistically two to three months, and a full season before hard wear.

Can I lay turf in summer?

You can, but it needs a great deal of water every day for a month, and a hosepipe ban would lose you the lot. Autumn is far safer.