Do you see different shades of green among lawns in your neighbourhood?
Do you see some areas of lawn turn a bit red, yellow, purple or orange?
Do some lawns look straw-coloured in spring?
Do you notice that some rolls of your new turf appear darker green than others?
If you answered yes to these questions or want to know what the various colours in turf indicate, study the details below.
In general, turf should be green, but the shade of green will vary among the species of grass, the time of year, the amount of fertilisation, the climate, the amount of moisture and even the direction of the sun. It is important to understand that your lawn is dynamic and is changing constantly. To the experienced turf scientist, each change in the colour of turf indicates a change in the turf's environment. Whilst most changes in colour are harmless, some are signs of danger. With a little effort, you too can identify the colour changes in turf and understand what they mean.
Colours, and what they mean:
Green - The chlorophyll in leaves reflects green colours. The darker the green, the greater the amount of chlorophyll. Nitrogen, iron and magnesium are important in producing the green colour of leaves.
Yellow - Carotenoids are pigments that reflect yellow colours in leaves. These are present in the leaves all of the time, but you only see them when the turf is deficient of chlorophyll. Deficiencies in chlorophyll occur from lack of sufficient nitrogen, iron, or magnesium, and also from diseases.
Red - Anthocyanins are natural pigments in leaves, and reflect red and blue colours. These too are present in leaves most of the time, but are only seen when either the chlorophyll content is low or they are produced in great quantities. When red is observed in turf, it can mean the grass is stressed, or it can be a harmless feature that differentiates that species of grass from others. For example, when leaves turn red in the cool spring and autumn it means that the plant cannot grow and produce chlorophyll very effectively. Usually, warmer temperatures will cure this situation. On the other hand, the red seen at the base of ryegrass leaves is a natural characteristic of that grass. Stress from disease can also result in higher levels of pigments.
Orange - Pigments that reflect orange light are generally not produced by the grass plant, but by fungi. Rust diseases that attack grass leaves produce spores that are orange or red-orange in colour. You can rub them off the leaf, whip them into the air with the lawnmower, or cover your wellies with them by walking through the turf. Rusts are pathogens that can kill the leaves of your turf, but, in general, they do not kill your entire turf plant. For more information on rust diseases and what you should do about them, see the section on Rust disease.
Tan - When turf turns tan or straw coloured, it is dead. Individual blades of grass will die, and under certain conditions the entire turf may die in patches. In general, the death of individual leaves can result from the natural ageing process, but this is generally a gradual process and not noticeable by a casual observer. Disease, drought, excessive heat or insensitive athletic use also can result in leaf death. There are noticeable warning signs. For example, when turf is very dry and hot it will first turn a bluish colour, and then die and turn tan. If your lawn is dying, there is a reason. If it is not obvious to you (for example, you did not water it, or you had the lads over for a lengthy rugby game), then contact a turf specialist, and get to the bottom of the problem before it gets worse.
Why your new rolls of turf may occasionally appear different from one another
We go to great lengths to ensure that the quality of each roll of turf is exceptional and uniform. Rolls of turf do not always co-operate, but the minor differences in appearance between one roll and the next are generally harmless, and only very rarely are indicative of a problem. One roll of turf can occasionally look and grow slightly differently from another. Differences like these are harmless, and are caused by the position in the field they were taken from, slight differences in the amount of fertilisation they received, or sometimes the amount of time they sat on the pallet before you laid them. Both differences in growth rate and colour will disappear without special treatment.
Your turf communicates by using colour changes; if you understand them, you can ensure a long lasting and beautiful turf.