Sowing new lawn areas can be easy and successful, providing you follow the correct procedure. The following information has been prepared after years of work establishing trials by our research and development team at Valley Seeds Research Station. When to sow varies with climate. As a rule of thumb spring and autumn are most successful. In cooler climates autumn sowing allows most grasses to properly establish their root system through the wet winter period prior to the drought stress of summer. If sowing in spring you must take particular care to water the area over summer.
In sub-tropical climates sowing can take place from autumn to spring. Try to choose a time in your area when your newly sown lawn runs the least risk of being washed away by seasonal rains or new growth burnt off by hot dry winds.
Step by Step Summary
For new areas that need leveling:
- Cultivate, rake and level the area to be sown
- Leave the area for 10-14 days or at least a sufficient time to achieve a germination of weed seeds present in the top soil.
- Spray a non-selective herbicide such as glyphosate to kill off the initial germination which has occurred during the seed bed preparation.
- Sow seed 24-48 hours after the application of the herbicide. At this stage the surface may have a hard crust on top. If this is the case, rake over the area using a steel rake or light harrows to loosen the surface.
- Spread a lawn starter fertiliser such as MAP at the recommended rate
- Sow seed after the fertiliser. To sow seed spread half in a north-south direction and half in an east-west direction. Rake again lightly. Avoid any further traffic and do not roll or tread the seed into the soil.
- Keep the area continuously moist until complete germination has occurred. In warm conditions, gentle watering may be required several times a day.
For over-sowing old lawns: (Simply rake and sow)
- Mow the area to a low height and rake off any surplus grass.
- Rake over the area using a steel rake or heavy plastic rake, enough to create some loose soil.
- Spread starter fertiliser.
- Spread seed as described above.
- Rake over again to incorporate seed and fertilise with some loose soil.
- Keep the area continuously moist until complete germination has occurred.
After Sowing Maintenance
In areas with dry summer conditions watering over summer will assist in maintaining a dense cover of grass. Start watering well before you see visible signs of the grass drying off or discolouration. A maintenance application of lawn “food” fertiliser should be applied at the recommended rate approximately 8 weeks after germination, or when most seedlings have reached a stage where each plant has 5 leaves. The type of fertiliser that should be selected for lawn food will have little or no Phosphorus, high Potash, high Nitrogen plus trace elements. The first mowing should take place at an approximate grass height of 80mm. During the first 12 months grass should be kept to a maximum height of 100mm and a minimum height of 50mm. This will have the effect of encouraging the grasses to grow horizontally and provide a dense cover. For many turf grass species less frequent mowing will be required if grass is kept to a minimum height of 50mm. If turfgrass is not mown below 40mm your lawn should remain thick, require reduced water usage and last longer. Over the first 12 months any significant infestation of broad leaf weeds should be controlled by applying selective broadleaf herbicides. Advice on appropriate herbicides should be obtained and directions for use followed precisely.