What to do after your lawn has been seeded

Seeding a lawn is the cheap part. Establishing it is the part that takes attention, and the window where it can go wrong is short. Once a seed has taken up water and started to swell, letting it dry out kills it. There is no second chance for that seed, and no amount of watering the following week brings it back.

Water little and often, which is the opposite of normal advice

An established lawn wants deep, infrequent watering. New seed wants the exact opposite. The goal is to keep the top half inch of soil consistently damp, never saturated and never dry, from the day it goes down until germination is through.

In practice that usually means short waterings more than once a day in warm weather, and less as conditions cool. Watch the surface rather than the clock. If it is going pale and dry between waterings, increase the frequency rather than the duration, because longer watering just runs off and carries seed with it.

Once the new grass is up and has been through a cut or two, start stretching the gaps and watering for longer. That transition is what sends the new roots downward. Staying on the germination schedule all summer produces a lawn with no root depth at all.

Keep off it, including the mower

Foot traffic on newly seeded ground presses seed too deep in some places and scuffs it out of contact in others, and it compacts wet soil at exactly the moment roots are trying to get into it. Keep people, pets and vehicles off the area until the new grass has knitted in.

That applies to the mower too. Wait until the new grass is tall enough to cut and the ground is dry enough to take the machine without rutting. Mowing wet seedbed does more damage than leaving it a week longer.

The first cut

Take the first cut when the new grass has reached a height where you can remove the top third and still leave a decent blade behind. Make sure the mower blade is sharp. A dull blade tears young grass out of soft ground rather than cutting it, and you will see the plants lying on the surface afterwards.

Cut high for the first several mowings. Longer blade means more leaf area, which means more energy going into building roots. Scalping a new lawn to make it look neat is the fastest way to lose the thin areas you were trying to fill.

Expect it to come up unevenly

Germination is not uniform, and a patchy looking lawn at two weeks is normal rather than a sign something went wrong. Different parts of the area dry at different rates, seed sits at slightly different depths, and shaded ground is slower than open ground. Give it time before deciding an area has failed.

• Thin patches on slopes usually mean seed washed before it rooted. Those spots may need doing again.
• Thin patches in shade are often permanent shade problems rather than seeding problems.
• Thin patches along paths and drives are usually heat and reflected light drying the surface faster there.

Weeds and feeding

Do not apply a broadleaf weed treatment to a newly seeded lawn. Young grass has no tolerance for it, and most products carry an explicit interval before they can be used on new seedlings. Wait until the new lawn has been mowed several times.

The same applies in reverse. A pre emergent application seals the soil surface against germination, and it cannot tell your grass seed from crabgrass seed. Seeding and pre emergent applications have to be planned around each other, which is one of the reasons the two are scheduled together as part of one programme rather than booked separately.

If you are unsure where your lawn is in that sequence, ring the office before applying anything yourself. It is a quick conversation and it saves a season.