Lawn Basics

There are many different types of grasses that are used as lawns but they can be broken into two groups:  cool season or warm season grasses.

Cool season grasses (like rye, fescue and browntop grasses) make up the majority of lawn types in New Zealand. They produce beautiful fine leaved lawns but require regular watering and low temperatures.  As such they are susceptible to prolonged dry periods and high temperatures.Peak growth periods are usually spring and autumn.

Warm season grasses (like couch and kikuyu) grow through the warmer months of the year. Little growth occurs during winter with some varieties taking on a brownish tinge as they become semi-dormant. They are only suited to a few warmer climate areas of New Zealand, for example Auckland and Northland, although a few lawn owners at the top of the South Island have also had some success with kikuyu lawns.

Lawn types can also be split into two groups ie spreading or clumping. Spreading grasses such as kikuyu and couch produce runners (stolons) or underground stems (rhizomes) which means they are able to self-heal if patches occur. Most of the warm season grasses are spreading types. Clumping types cannot do this and bare patches need to be filled by sowing new seed. Most cool season grasses are clumping types with very little to no lateral spread.

Installing a New Lawn
The two main options for establishing a new lawn is to either sow seed or lay ready lawn. Seed is cheaper than ready to use ready lawn but it takes longer to establish. Not all lawn varieties are available as seed whereas they may be available as ready lawn. Ready lawn also gives you that beautiful instant lawn effect but comes at a higher price.

Whichever way you go it’s important to keep the lawn moist until it is fully established.

Water Requirements
Unfortunately that beautiful lush lawn we all want can require a fair amount of water. Here are a few tips to reduce water requirements:

• Water lawns deeply and then leave a period of time before watering again to encourage deeper root systems. Aim to water no more than once a week during summer and less in cooler periods.
• Reduce the area of lawn you have if it’s not needed.
• Change the variety of grass you have to one that is more drought tolerant such as kikuyu or tall fescue
• Accept that your lawn does not need to look like a golf green all through summer and that you can live with some browning off.
• Use seaweed year round to help stimulate root development (spring and autumn), increased stress resistance (summer) and increased frost tolerance (winter).

Fertilising
Apply a organic pelletised lawn-grade chicken manure product every three months when the lawn is actively growing. It contains beneficial plant nutrients such as nitrogen and potassium in ideal levels for the lawn and is a great way to avoid peaks and troughs in growth often seen with synthetic fertilisers. The organic matter found in organic fertilisers will help to increase the water holding capacity of the soil making moisture available for longer to the lawn. The increased organic matter will also  encourage beneficial microbes and macros (earthworms etc) activity, improving your lawn through better soil health.

In spring and autumn apply OCP eco-flo lime to boost the soils calcium levels as well as preventing the soil from becoming too acidic.

Mowing
There’s no getting around the fact that lawns need regular mowing. Lawns respond well to being cut as it encourages the plants to grow out rather than up. These leads to a nice dense lawn. If left to their own devices many lawn types will grow very tall and block light to the lower parts of the plant. When you eventually mow it you’ll be left with a very sparse looking lawn which is vulnerable to weed invasion.

Also consider buying a mower with a mulching setting. It finely chops up the clippings and leaves them on the lawn. These settle through the lawn and form a fine mulch on the soil surface reducing moisture loss and returning nutrients to the soil as they break down. The setting is generally not used all the time otherwise thatch can build up too quickly.

Compaction
Lawns receive a lot of foot traffic and commonly suffer from soil compaction as a result. This is where the soil particles get pushed together tightly from all the walking, jumping and running that occurs on the lawn. These compacted particles take up what would otherwise be tiny pockets of air in the soil which allow for roots to breath and water to drain through efficiently. Lawn grows poorly as a result.

For small areas you can repeatedly push your garden fork into the soil about 10cm deep. This will create lots of small holes opening up the soil. For larger areas you can hire a coring machine that will pull out little plugs of soil and also create small holes throughout the lawn area. Whichever method you choose you should then sweep/rake a layer of sand across the lawn to fill up these small holes. The sand aids in aeration and stops the hole just closing up straightaway.

If your soil has a clay component to it then apply eco-flo gypsum 1-2 times a year (spring and autumn) to help break up the clay. The liquid formulation of eco-flo gypsum means it works much faster than powdered gypsum and is easier to apply.

Dethatching
Over time it is very common for dead material (leaves and stems) to build up within the lawn. This material is called thatch and is what makes some lawns feel spongy. High levels of thatch restrict airflow which increases the risk of turf diseases. It also blocks sunlight to the lower parts of the grass causing it to thin out. Thatch can be removed by hand using a stiff rake and lots of elbow grease. Alternatively, you can hire a dethatching machine which is a lot easier and faster.

For really spongy lawns (as can commonly happen with kikuyu) you may need to scalp the lawn first with the lawnmower by cutting it extremely low. This removes the bulk of the top thatch allowing access to the lower thatch material.

Whichever way you go about it a dethatched lawn looks like a mess so be prepared for it look worse before it starts looking better. Its best done in spring when grasses will quickly put on new growth.