Seeding New Lawns
1) Site the area to be seeded, if possible in full sun, with a maximum fall of 1:80
2) Leave a mowing strip of 100-150mm where the lawn will meet walls, fences etc. Grade the soil after cultivation 25mm above adjacent paths and paved areas.
3) Clear site of builders rubble, foundations, debris and any solid structures.
4) Control weeds before sowing. Annual weeds may be hoed, buried or killed with a contact herbicide. Perennial weeds such as Couch-grass, Docks, Thistles, Ground Elder and Thistles should be eradicated by a translocated Glyphosate herbicide (“Tumble Weed/Roundup”)
5) Cultivate topsoil by spade or by powered cultivator to produce an evenly cultivated soil depth of at least 150-200mm.
6) Grade the topsoil with a hand rake or power-rake to produce as even a surface as possible.
7) Incorporate any drainage system or irrigation system at this stage, taking care not to mix sub-soil and topsoil together.
8) Incorporate ameliorants ( Soil Improvers such as Washed horticultural grade sands or grit/sands for improved drainage or finely graded organic soil improvers for moisture retention)) at this stage. Ensure that any ameliorants are evenly mixed into the topsoil to achieve a homogeneous mixture.
9) Regrade the soil by hand rake to finished levels and consolidate (firm the soil by treading or roller) sufficiently to remove any voids and to avoid later settlement.
10) Apply fertiliser (e.g. Growmore) with a plant food ratio of 2Nitrogen: 3Phosphate: 2Potash, evenly and at the manufacturers recommended settings, using a fertiliser distributor.
11) Sowing times will depend on whether irrigation is available. Without irrigation, sow in the spring from late March to early May and autumn sowings from mid August to mid September. If irrigation is available sow throughout the growing season.
12) Take care to sow the seed evenly at the rate indicated by the supplier. Generally a rate of 50 gms/m2 will produce excellent results, but a lower rate of 35gms/m2 may be applied where perfect conditions of warm soils, good soil moisture, availability of irrigation and accurate seed application are guaranteed.
13) Rake the seed in lightly with a spring tined rake and firm the seed into close contact with the soil to ensure good moisture uptake, by treading or preferably by rolling.
14) Irrigate the surface with a fine spray to avoid disturbing the seed or the soil. Keep well watered.
15) Germination time will vary depending on several factors but generally the various seeds in the mixture will take around 5 – 28 days for complete germination. Not only will the new grass grow, but so will any broad-leaved and grass weed seed present in the soil.
16) Once leaf blade growth reaches 35-45mm, roll the surface of the lawn to anchor the roots of the new shoots (they are easily pulled out of the soil) and to press any stones back into the soil, mow the lawn with a very sharp bladed mower set to remove no more than 25% of the leaf blade length, remove the mowings whilst cutting ( a rotary mower is ideal).
17) During the first 12 months of establishment do not mow any closer than 25mm.
18) If the lawn was spring sown, growth will be vigorous. Mow at least twice a week, taking care to maintain the same mowing height.
19) During prolonged dry periods, growth will slow down and the mowing may only be required once a week, but be sure to maintain the watering during this first year of lawn establishment. Apply a High nitrogen spring/summer fertiliser after 4-6 weeks from germination to maintain growth and plant development.
20) Any areas where the sward is thin or seed has not ‘taken’, over-seed with the same mixture to improve sward density
21) After the first 12 months of lawn establishment, a closer mowing regime may be commenced (provided the mixture mowing guidelines allow it – some grasses will die out if mown too close). Remember, the density of the grasses in the lawn will be improved by increasing the frequency of mowing. A lax mowing frequency will produce a lawn where the soil can be seen between the grasses and in these gaps weeds and moss will grow.
22) If it is unavoidable that the lawn is left to grow without mowing (such as holiday periods or terrible weather), make sure that you do not cut back the lawn to its original maintained height of cut in one pass as this will seriously damage the lawn. Reduce the height of cut gradually over a period until the original height of cut is achieved – you may well still lose some sward density, but you will not permanently damage the lawn.