The grass is greener

Article originally published by: Kiwi Gardener

Nearly every garden in New Zealand has at least one patch of lawn. Lawns are an important feature of landscaping and, better still, provide that unmistakable fresh scent when cut. Australian visitors always sigh in jealousy when they see our lawns so lush and green.

Annual lawn maintenance

To function well, lawns require a regular programme of care and attention. Most activity to maintain lawns occurs in spring or in autumn. Servicing lawns is best in these two seasons when both temperatures and humidity are relatively stable. Summer is too hot and dry and winter is too wet and cool for grass to successfully grow well.

De-thatching is the process to remove excess straw and dried roots left over from the previous summer. Raking the whole area is hard work. Machinery that de-thatches is available for hire or contact a professional to come and de-thatch the lawn for you.

Lawns need regular spraying for a variety of reasons. The ideal lawn is composed of grass varieties only. Wind, insect and bird conveyance see a variety of unwanted broadleaf weeds and plants seed down in the lawn. Clover, plantain, dandelion, buttercup, yarrow, onehunga weed (prickle weed), dock, pennyroyal – the list goes on and on. While some gardeners accept these as part of lawn growth, others despair at the invasion and will set up a regular spray programme to eradicate unwanted plants. The expert at the local garden centre can set things right with good advice as what to spray and when. Broadleaf sprays, for example, target and kill just those weeds, while leaving grass varieties alone.

An organic option to rid the lawn of unwanted plants is simple, but slow. Armed with a shallow container of salt, dig each unwanted plant out and then put a pinch of salt onto any remaining roots.

Moss can build up in cool, damp winters and can be removed by raking the patches out. There are iron sulphate lawn sprays to kill off moss and the resulting bare patches can be repaired.

Grass grub and porina moth larvae attack roots and grass blades, depleting the lawn. You can either rely on starlings to eat these or apply a granular insecticide.

All plants need fertilising to grow well and maintain good plant health. There are mixes of granular fertiliser that ensure grass achieves its required nutrient levels. Apply fertiliser in spring and again in autumn.

The traditional method of application is to have a bucket full of fertiliser that is thrown, a handful at a time, as one paces up and down the lawn area covering a grid pattern to ensure even distribution. Most garden centres sell fertiliser and seed spreaders – wheeled machines that distributes fertiliser as the applier walks around the lawn area.

In summertime droughts, lawns can suffer and develop bald areas. To break up the soil surface, rake it over and then apply more grass seed. Topped up with a light scattering of sand, the area can then be well watered and new growth will appear quickly.

1. Ideally lawn is grass varieties only, but moss and thatch are common invaders. 2. There are sprays to target specific weeds, such as broadleaf. 3. Moss can build up over winter. 4. Before laying lawn, use a levelling tool to create an even surface.

Mow time

Regular mowing keeps lawn in the best condition. Cutting grass too low will affect the new growth of its blades and can cause stress. Neglecting lawns and then randomly cutting them back can also be detrimental to grass health.

Mowing once a week in spring and autumn is a good regime to adopt, with fortnightly or monthly mowing in summer (minimal growth) and in winter (cold, short days). Keep a careful eye on growth as it is essential for the lawn to be well trimmed and maintained.

Types of mowing machines vary – from push mowers and rotary mowers, to ride-on versions. There is diversity to suit all situations. Mulching mowers are another option, and these distribute the clippings back onto the lawn area, which can be a bonus if you don’t have composting facilities.

Lay a new lawn

  • Spray off the area. This will get rid of the broadleaf and any other unwanted weeds.
  • Know your soil. Is the soil sand, peat, clay or alluvial based? Each of these soil types require different approaches, so analysis is important. Sandy soil will be porous and quick to dry out; peat soil is also porous, and acidic. Clay is heavy and can cause drainage problems, retaining excess winter water and being susceptible to waterlogging. Alluvial soil is best, as it’s high in nutrients and well balanced.
  • Lawn soil. A layer of lawn soil can be spread over the ground to improve the soil condition.
  • Rotary hoe. If the ground is uneven, rotary hoe to remove bumps and hollows.
  • Level. Add dirt for hollows and remove bumps by using a leveller.
  • Roll dirt. This will compact the soil and make a firm base.
  • Drainage. If the ground is not level then it might need drainage pipes laid underground to ensure rainfall will drain away to stormwater systems. Concreted areas and raised garden edges can block natural drainage. Water always seeks the lowest point and building up the soil level can help change water flow.
  • Decide on seed. Farm supply agents stock many varieties of grass-seed mix. They have grass seed in large volumes and will provide advice on the recommended rate of application. Garden centres also stock grass seed in small packs, which are ideal for patching bare lawn areas. The most prevalent lawn seed is a mix of fescue (Festuca), rye (Secale cereale) and browntop (Agrostis capillaris).
  • Lawns that host children playing, pets running or sports games are going to need different seed selections. Tennis, croquet and bowls lawns need special grass seed combinations and might include non-grass seed.
  • Spread seed. Use a seed spreader for even distribution.
  • Irrigate for germination. Once seed is down, it must be kept moist to start growing. If seed dries out, it can die. In spring, there is enough residual moisture in the ground to ensure good germination.
  • Mow the new lawn. Let the lawn grow for at least six weeks before it gets its first mow. For the first few cuts, mow the lawn high. This will encourage the roots to form a solid base.
  • Maintain. When the lawn is established, keep up a regular lawn-maintenance programme.