HOW TO GROW A LAWN FROM SEED
If you want to grow a successful, quality lawn from seed then the first thing you will need to know is that it is ALL about the preparation! In fact the decisions you make before you even start to work on your new lawn can have a crucial effect on the end result.
With that in mind, first give some thought as to what you want from your lawn, not just for this year but for years to come. Do you want a square lawn, a shaped one, or do you want a lawn with flower beds cut into it? Will it need to be hard wearing or tolerant of shade?
A lawn will not need to be perfectly horizontal, but you'll probably want to avoid steep slopes otherwise you can end up with drainage issues - i.e. Dry at the top and damp at the bottom – which can result in moss or weed problems further down the line.
However, it is important to remember not to mix up top soil with sub soil. Although it may seem a lot more work, the correct way to achieve this is to remove all of the top soil from the area that is being levelled, then backfill the lower end with sub soil taken from the higher end. Once completed, replace the top soil back over the whole area.
Unfortunately, if the ground has been levelled by more than about a foot you will need to leave it to settle for at least a year before seeding your lawn. Why? Because the ground will invariably sink over time and this will most likely be at an uneven rate across the whole of the area worked.
PREPARING THE SITE
The proposed area for your new lawn will need to be well drained. If the area suffers from damp or even periodic water logging, it may be necessary to lay either a soak away or drainage pipes under the soil. If drainage problems are not dealt with at this initial stage then you are only opening the door for plenty of work later on.
Furthermore, if there is any builder’s sand left, do not be tempted to dig it in - you need 'sharp sand' to condition soil not 'builders sand'. Start by removing all large stones, blocks and any obviously non-organic rubbish from the surface.
A lawn will grow best on well drained medium loam. If this sounds like your soil then your preparation can be minimal, but if the soil is clay or sandy, you'll need to do more work.
With heavy clay soils, you should add sharp sand, and any well-rotted organic compost as this will improve drainage under the lawn.
With sandy soils, you should just add well-rotted organic compost as this will help to improve moisture retention under the lawn.
The top soil will need to be prepared to give a fine, workable tilth to a depth of 4 to 5 inches. If you are adding organic matter, you should aim for a minimum depth of 6 inches. If the area of the lawn is fairly small, it can be prepared by hand using a spade. For larger areas it is worth using a rotovator.
When starting to prepare the soil, it needs to be not too dry and not too wet. Start by digging or rotovating the whole area to the required depth, breaking down any large clumps of soil and remove any stones or rubbish you come across.
TIP. When digging, work backwards so you don't tread down the soil you've just broken up.
Rake over the area to level it while removing any vegetation, stones or rubbish which may appear. Now leave the area to settle for a week.
If a lot of weed or vegetation appear in the first week, consider using a non-residual herbicide to kill them off. Carefully follow the instructions and leave the soil for the recommended period before proceeding.
Rake over the area again and remove any more vegetation, stones or rubbish which may appear.
Tread down the entire area. Start in one corner, then walk slowly across the soil placing one foot in front of the other. When you reach the other end, turn around and repeat until the whole area has been trod down (if the area is large, you may need more than one person!). The first time you do this, you'll probably find some humps and dips, remove these by giving the surface a light racking and repeat the treading down.
SOWING THE LAWN
Sow the lawn on a wind free day, but just before you start sowing, give the area one last rake over Divide the quantity of seeds into two, (it is better to sow two lighter sowings rather than one heavy one). If the area to be sown is large, you can divide the seeds further. This will reduce the chances of covering three quarters of the area and finding that all the seed has gone!
Sow one covering of seeds while walking in one direction, and the second sowing while walking at right-angles to the first covering.
Lightly rake the seed into the top of the soil, you won't cover all the seed but try to cover about half. Once finished the area should not be walked on so you may wish to cordon off the area until the new lawn is in place.
Grass seed should germinate within 7 to 21 days depending upon the weather. If a dry period occurs then you may wish to water during this germination stage, use a gentle watering technique (a garden sprinkler or hose with a fine spray attachment pointed skywards) to keep the top of the soil moist.
TIP. Too much water applied in the early days can float the individual seeds into concentrations.
When the grass is about 1 inch high, gently roll the area with a light garden roller. Alternatively, if you have a cylinder mower, set the blades as high as possible and use this instead. If you have just a small patch of lawn, you may be able to get away with treading the area in the same way as was done before the grass seed was sown.
Avoid mowing the grass until it is about 3 inches high. After this first cut, lightly mow the lawn with the cutter set to about 2 inches. If you are not using a cylinder mower, you will still need to lightly roll - or tread - the area after the lawn has been cut.
Further reduce the cutting height of your mower with each subsequent mowing - and still roll after each mowing - but don't cut lower than 1 inch during the first season.
NOTE. Keep playing children and pets off the lawn for the first season, the first year grass seedlings are plants and need time to become established.