Most of the questions people ask about a new lawn focus on feeding. When do I feed it, what do I feed it with, why is it not thickening up after a few months? The honest answer is that for the first six months of a new lawn, feeding is not the priority, and in many cases it is the wrong thing to reach for altogether. What a new lawn needs in order to establish properly is good soil. Get the soil right before you sow or lay turf and the grass will look after itself. Rush to feed a lawn that is sitting on poor, compacted or unimproved ground and you will be spending money on a product that cannot do its job, because the conditions below are not right to support it.
Prepare the soil before you sow or lay turf
The single most valuable thing you can do for a new lawn is invest time and effort in preparing the soil before a single seed is sown or a single roll of turf is laid. This means digging over the area to a depth of at least twenty centimetres, removing stones, breaking up compaction and improving the structure of the soil throughout the root zone. If the soil is heavy clay, working in sharp grit and organic matter will dramatically improve drainage. If it is thin and sandy, organic matter will help it retain moisture. In both cases, incorporating a biochar-based soil improver at this stage does something that ordinary organic matter alone cannot do as effectively. Biochar improves the structure of the soil, increases its ability to hold nutrients and water, and supports the microbial activity that makes soil genuinely healthy rather than just structurally adequate. If you are not sure what you are working with, garden soil in Ireland explains the main soil types and what each needs.
Use NutriChar when you prepare the ground for a new lawn
Work NutriChar into the soil while you are preparing the ground, before you sow seed or lay turf. It encourages good germination and strong root development from day one, because the nutrients are locked into the biochar structure and held in the root zone where the young grass needs them, rather than washing away. It also improves soil structure and moisture retention, so the new lawn establishes on a foundation that keeps working long after the grass is down.
The work you do on the soil before the grass goes down will determine how that lawn performs for years. It is the investment that cannot be made afterwards without starting again.
Whether seed or turf is right for your garden, and when to do it, is covered in how to lay a new lawn in Ireland.
The first six months: establishment, not feeding
Once the lawn is down, whether from seed or turf, the priority for the first six months is establishment rather than feeding. The grass needs to develop a strong root system, and that process is supported far more by good soil conditions than by additional nutrients applied to the surface.
If bare patches appear in a seeded lawn during the first season, the answer is overseeding rather than feeding. Overseeding simply means scattering fresh grass seed over the thin or bare areas, raking it lightly into contact with the soil, and keeping it moist while it germinates. Done in spring or early autumn, when soil temperatures are warm enough for germination, this fills gaps reliably and costs very little. It is a much more effective response to patchy establishment than feeding, which will do nothing to fill in areas where the seed simply did not take.
The temptation when a new lawn is not thickening as quickly as expected is to apply a lawn feed in the hope of speeding things up. Resist this for the first six months. Grass plants in their first season are focusing energy on root development, and premature feeding with high-nitrogen products can push top growth at the expense of those roots, leaving the lawn looking green briefly but ultimately weaker and shallower-rooted than it should be. Patience is the better option. A lawn that has been properly prepared, seeded at the right time and kept watered during dry spells in its first summer will establish well without any additional feeding.
When to start feeding, and what to avoid
After the six-month mark, when the lawn is properly established and actively growing, you can begin a feeding programme. At this point, the choice of product matters. Avoid anything based on sulphate of iron. This is sold widely in Irish garden centres and garden superstores, often as a component of combined lawn treatments. It will green up the grass temporarily, but it does so by acidifying the soil, and lower soil pH creates exactly the conditions in which moss thrives. In Ireland's warm, damp climate, moss is always ready to establish wherever soil conditions invite it, as explained in moss on my lawn.
Choosing a feed that maintains or gently raises the soil pH, rather than lowering it, keeps the lawn in conditions that favour grass over moss throughout the growing season.
Mowing height for a new lawn
Keep it high. Cutting a new lawn too short removes leaf area the plant needs to photosynthesise, slows root development and exposes bare soil to moss and weed colonisation. Three to four centimetres is the right cutting height through the first season and beyond. Taller grass is healthier grass. It has deeper roots, retains moisture better and is significantly more resistant to both drought and moss than a lawn that is regularly scalped. For timing and approach, see the first grass cut of the year in Ireland.
New lawn questions
When should I start feeding a new lawn?
Not for the first six months. In its first season a new lawn is putting its energy into root development, and feeding too early with high-nitrogen products pushes top growth at the expense of those roots. Once the lawn is established and actively growing, after around six months, you can begin a feeding programme.
What should I do about bare patches in a new lawn?
Overseed rather than feed. Scatter fresh grass seed over the thin or bare areas, rake it lightly into contact with the soil and keep it moist while it germinates. Spring or early autumn, when the soil is warm enough, gives the most reliable results.
Should I use sulphate of iron on my lawn?
I would avoid it. It greens the grass up temporarily, but it acidifies the soil, and lower soil pH creates exactly the conditions in which moss thrives in Irish lawns. Choose a feed that maintains or gently raises soil pH instead.
How short should I cut a new lawn?
Keep it high: three to four centimetres through the first season and beyond. Taller grass has deeper roots, holds moisture better and is far more resistant to drought and moss than a lawn that is cut short.