Mistakes that are hurting your lawn – Part 3

Daleys Turf has collated some of the most common mistakes that are being made in backyards across Queensland and our recommendations on how to fix them. Mowing and watering was covered in Part 1 and Part 2, now lets move on to Part 3:

A few of the biggest mistakes made when it comes to using fertilisers is not only using the right mixture, but using the right quantity and applying it at the right time of the year. Often when spring comes around people feel the need to fertilise their lawns in hopes of seeing a green plush lawn as soon as possible. Too much fertiliser, especially with high levels of soluble nitrogen, tends to increase thatch problems and leaves lawns more prone to attack by insects and disease. Or, worse yet, you will literally burn your lawn.

The goal of a good fertilising program is to produce a reasonable amount of top growth, but not at the expense of root growth or carbohydrate storage. A good root system is the key factor to a healthy lawn. Nitrogen (N), Phosphorus (P), Potassium (K); Lawn fertilisers typically contain these three nutrients although, other nutrients may be included in small amounts. The three numbers on the fertiliser bag represent the percentages of N, P and K in that order. The back of the fertiliser bag should show the guaranteed analysis. Always follow the recommended application rates suggested by the manufacturer on the bag. The grass plant needs more nitrogen than any other nutrient. Nitrogen is part of the chlorophyll molecule and helps give the lawn its deep green colour. Nitrogen also tends to promote high leaf growth rates at the expense of root growth. Phosphorus is responsible for the energy transfer systems in the plant and is generally required in much smaller amounts than nitrogen or potassium on an established lawn. The exception is for newly established lawns by seeding, sodding, or sprigging, when the need of phosphorus is higher in the new plant. Potassium has a lot to do with good cell wall development and the plant’s ability to withstand stress, disease and insect damage.

Look for slow-release forms of nitrogen. 

The two basic forms of nitrogen that can be used as a fertiliser are organic and inorganic. The most commonly used inorganic forms of nitrogen in fertilisers are ammonium nitrate and ammonium sulphate. Both are soluble, quickly available forms of nitrogen and both tend to produce a fast increase in leaf growth for a fairly short period of time. More and more, the slowly soluble or slow-release organic forms of nitrogen are being recommended by lawn care experts. These include sulphur-coated urea, urea formaldehyde, I.B.D.U., methylene urea, natural organics, and resin-coated urea. These tend to produce a lawn with good colour without excessive leaf growth. They are designed to dole out the nitrogen over a longer period of time. The slow-release forms of nitrogen do not have to be applied as often.

What fertiliser should I use? 

Most lawn care experts recommend that a lawn fertiliser should have at least one-half of its nitrogen in one of the slow-release forms mentioned above. Most lawns will do well when a 3-1-2 or 4-1-2 ratio of N-P-K is used on an established lawn.

How much fertiliser should I use? 

Fertiliser application rates should be as low as possible and still produce a high quality lawn. Over-fertilisation weakens your lawn and causes excess leaf growth. Always follow the manufacturers recommended application rate.

When should I fertilise? 

The best time to fertilise a lawn is when it is actively growing. In Queensland it is best to concentrate a larger amount of nitrogen during the early-late spring applications and a lesser amount in the cooler months. Frequency of fertiliser applications depends primarily on the amount and form of nitrogen used. The slow-release type fertilisers can adequately feed your lawn from 6 to 10 weeks. If the lawn still looks good and is growing well after 6 to 8 weeks, wait longer for the next application.

IMPORTANT: By leaving your grass clippings on the lawn you are adding nitrogen almost continually, which can reduce the need for fertilisation by as much as 25%. And, leaving the clipping on the lawn helps the environment by keeping clippings out of landfill.

Thatch is that tightly packed layer of dead and living shoots, stems, and roots that develops between turf or grass and the soil surface. Dethatching takes a little time and effort and using the wrong dethatching equipment can make it a huge effort when it needn’t be. Some dethatching machines have flexible, leaf rake-type tines that are ineffective in removing thatch. Spring tines that attach to a rotary mower blade aren’t good for dethatching and can damage your mower. It’s important that you use the right equipment if you are going to dethatch. Don’t attempt to remove the entire thatch layer in one treatment and do not dethatch when soil is wet; only dethatch your lawn when it is needed rather than on a routine basis.

A little thatch is desirable, since it helps moderate temperature extremes at the soil surface and provides a cushion effect on the surface but too much thatch can present some negative consequences. To determine if your lawn has a thatch problem, remove a small, plug of turf several inches deep. Note the spongy layer of material between the turf and the soil. If this layer is more than 2.5 cms thick when you compress it, you should consider having your lawn dethatched or begin a program which will encourage thatch decomposition. If you need to dethatch your lawn there are garden centres and equipment rental outlets that rent dethatchers. These machines are known as vertical mowers, verticutters, dethatchers or power rakes and they have vertically spinning blades which pull some of the material to the surface as they slice the thatch layer. Mechanical dethatching should be done in either late summer or when cool weather prevails. As is the rule when operating any equipment, follow the manufacturers or rental store’s operating procedures. The organic material dislodged by the dethatching machine should be removed and composted. It’s also important to note that grass clippings do not cause thatch and they are good for your lawn.

For more information on lawn care mistakes you might be making and how to avoid them just contact the team at Daleys Turf today – with you for the life of your lawn.