In the spring, a lawn may need help to encourage new growth and to establish strong roots before summer. Spring is time to fertilise, dethatch and scarify.
As grass doesn’t grow flower, it needs a different type of fertiliser than other garden plants.
The important thing to understand about lawn food is the N:P:K ratio:
- The “N” is for nitrogen - that gets the leaves green and growing.
- The “P” is phosphorous, that’ll make the roots grow strong and deep.
- “K” is for potassium, which strengthens the plants and helps the grass cope with drought and resist disease.
A lawn food that is nearly all nitrogen will cause turf to green suddenly, resulting in a massive growth spurt in a very short time, but this isn’t enough to promote a strong root system.
After the next mowing, most of the nutrients which are only in the leaves are gone. Because of its fast and tall growth, the lawn will look scalped after mowing, creating a perfect condition for new weed growth.
Balance is important in a fertiliser which will encourage growth in all the right areas, both above and below ground. Look for an N:P:K ratio of approximately 11 for nitrogen, 2-4 for phosphorus and 8 for potassium along with some calcium and trace elements.
Thatch Removal & Scarifing
If the lawn has “sponginess” there is a build-up of thatch from old and dead grass that lies just above the soil and root system. Thatch will stop air and moisture from reaching the roots and creates a micro-climate that encourages fungal disease.
Over time, all lawns build up a layer of dead grass, or thatch, at their base and thatch removal is necessary. Never dethatch a lawn just prior to winter as it will not recover green leaf until the spring.
- Thatch is best removed starting with a rotary mower to slash the lawn down almost to the soil. Use a metal-tinned rake to remove the excess thatch.
- For severe cases or if there is black layer of old crusted organic matter, it’s best to rent a dethatcher or scarifier from an equipment hire outlet. These tools cut through and remove unwanted material.
Many mowing contractors offer a comprehensive dethatching service for a moderate fee. Spring maintenance will make the lawn stronger against diseases, patchiness, moss and weeds.