Sod Quantity & Cost Calculator

For the first two weeks, the sod and the soil beneath it must stay continuously moist. In warm weather that means watering every day and sometimes twice, and it means checking rather than assuming: lift a corner and feel the soil underneath, because the surface can look damp while the soil below is dry.

The test for whether it has taken is straightforward. From around week two, tug gently at a corner. If it lifts, roots have not yet knitted into the soil beneath and it still needs the full regime. If it resists, establishment is under way and you can begin reducing frequency and increasing depth.

From weeks three and four, water every other day and go deeper — the aim shifts from keeping the sod damp to encouraging roots down into the soil. By weeks five to eight, twice a week. After that it is an established lawn and can move to a normal deep-and-infrequent schedule.

One thing worth planning around: this regime is not optional and it is not flexible. If you are going away for a week in the fortnight after delivery, move the delivery.

Sod laid on unprepared ground fails, and it fails in a way that looks like bad sod rather than bad preparation.

The existing lawn has to go. Not mown short — removed, or killed and raked out. New roots cannot penetrate an existing thatch layer, so sod laid over old grass sits on top of it, never knits, and dries out. A hired sod cutter does this in an afternoon and is the single best money spent on the project.

The soil beneath then needs loosening to a few inches, because sod roots will not enter compacted ground. If the previous lawn failed from compaction, laying new turf on the same compacted soil produces the same result more expensively.

Grade matters next, and it is the moment to fix drainage problems while the surface is open. Slope away from the house at a minimum of about two per cent, fill hollows that held water, and rake to a fine even finish — every bump and dip is permanent once the sod is down and will show every time you mow.

Finally, moisten the prepared soil before laying. Sod laid onto dry soil is fighting from the first minute.

The comparison in the result uses identical site preparation and removal costs for both routes, which isolates the actual difference rather than flattering seed by ignoring the work they share.

On that basis sod typically costs three to five times what seed does. What you get is a lawn immediately, a usable one in about three weeks, essentially no weed competition during establishment, and the ability to establish outside the narrow seeding window.

Seed gives you a cheaper lawn, a wider choice of cultivars, and better long-term root establishment — grass grown from seed in place develops a deeper root system than transplanted sod. It also gives you two to three months of bare soil, weeds, and the risk that a heavy storm washes the seed into one corner.

The honest recommendation depends on the season and on slope. In autumn on flat ground with no urgency, seed is usually the better value. In late spring with children who want to use the garden, or on any slope where seed will wash, sod earns its premium.

Sod can be laid in more conditions than seed can be sown, but it is not season-agnostic.

Cool-season grasses — fescue, bluegrass, rye — establish best in autumn, with early spring second. Laid in midsummer they need enormous quantities of water and the failure rate rises sharply.

Warm-season grasses — bermuda, zoysia, St Augustine — want late spring into summer, when they are actively growing. Laid in autumn they may not root before dormancy, which means an entire winter of vulnerable turf that has not attached to anything.

Choose the grass for your climate and your site rather than for its appearance in a photograph. Shade tolerance in particular varies enormously: St Augustine copes with shade well for a warm-season grass, bermuda does not cope at all, and no grass thrives in deep shade regardless of what the label claims.