Turf Grasses

Course CodeBHT342
Fee CodeS3
Duration (approx)100 hours
QualificationStatement of Attainment

An Essential Course for all who work in the Turf Industry

Learn to compare, understand, select and manage the best turf grass cultivars for the need at hand.

  • Sports Turf
  • Parks
  • Commercial Lawns
  • Residential Lawns

When choosing what species and cultivar of grass to grow, you need to measure that choice against the criteria which are most important for the situation in which you are growing that turf. If the turf is intended for a very specific and refined purpose, such as a bowling or putting green, the factors which impact most on that purpose will be of greatest significance. If the purpose is simply to cover the ground with the least costly green, living, surface; the criteria considered may be less rigid.

This course is being developed and will be available February/March 2017

 

Lesson Structure

There are 10 lessons in this course:

  1. Scope, Nature and Taxonomy of Turf Grasses
  2. Fescue Grasses
  3. Bent Grasses
  4. Rye Grasses
  5. Blue Grasses
  6. Couch Grasses
  7. Buffalo and Zoysia Grasses
  8. Other Warm Season Grasses
  9. Other Cool Season Grasses
  10. Turf grass Mixtures

Each lesson culminates in an assignment which is submitted to the school, marked by the school's tutors and returned to you with any relevant suggestions, comments, and if necessary, extra reading.


 

EVERY GRASS CULTIVAR IS DIFFERENT

You may be surprised how much different grass cultivars vary; even within a species.
Every situation you utilise grass to grow a turf, will be a different situation. The microclimate in the soil and above will vary. The susceptibility to pest and disease is different in different locations. The way in which the turf will be used and maintained is equally variable. When you make choices about what turfgrass to use, you need to understand all of these variables, and all of the relevant characteristics of the options before you.

Consider such things as:

Persistence

It is always preferable to use grasses that can recover from damage (eg. after sport is played on it, or after extreme weather); and have a long lifespan.

Quality of Turf

It is always better to use grasses that will adapt to mowing, and produce a surface that is desirable. Many grass species simply do not do this, and that is why the range of grass species used for turf is limited.

Rate of Establishment

It is important to use grasses that establish fast enough that they will cover and bind the surface, leaving no soil exposed, before soil has any opportunity to erode, or weeds have any chance to invade.

Leaf Texture

Consider how coarse or fine the surface needs to be. The width of the leaf blade contributes strongly to texture. Wider leaf blades will obviously make for a coarser grass. Stiffness or softness of the leaf also affects texture. Some leaves can have abrasive or sharp margins or surfaces; and others very soft and gentle -another contributing factor

Shoot density

Consider how many shoots develop per unit area. For a fine leaved grass in a high quality green, it is critical to have a much larger number of shoots in order to achieve a smooth surface.

Cold and heat tolerance

Most turf grasses are frequently described as either cool season or warm season grasses. Cool season cultivars tend to have more active growth across a lower range of temperatures; and warm season grasses across a higher range of temperatures. The range within which they are growing is not the same as the climate in which they can be grown.  For example: warm season grasses that survive in or tolerate low temperatures may be well suited for use in a temperate climate turf, mixed with cool season grasses. Couch is a warm season grass that grows over spring , summer and autumn in a temperate climate. It may be grown with rye grass that grows

Drought tolerance

Consider whether irrigation might be needed always or sometimes, and whether it is available.

Shade tolerance

This is a frequent cause of deterioration of grass. Generally shade is only a problem on some greens surrounded by tall trees or buildings, such as bowling or golf greens. In residential and commercial landscapes, or public parks though; shade can be an issue. If grass is shaded by trees, consider the intensity of shade at different times of the year. Whether trees are deciduous can also be a factor.

pH tolerance

If soil pH is extreme, your choice of cultivar can be limited; but there are some cultivars still that will tolerate very acid or very alkaline conditions.

Salinity tolerance

Some cultivars do tolerate high salinity. In coastal regions, salt in the air can be as much of an issue as salt in the soil. In some places, irrigation water may also contain salts.

Flooding and waterlogging tolerance

Some cultivars will survive even submerged in water; but most will not. If waterlogging is a likely proble, even only occasionally; be careful to select cultivars that will tolerate such conditions.

Soil fertility

Heavier or organic soils are more likely to contain the nutrition required by a turfgrass; but such soils might not drain as well. Better drained, and sandy soils will lose nutrients (through leaching); and constant mowing and removing clippings will also remove nutrients. If a soil is fertile and clippings are not removes, fertilising may not be as important to maintain health. Without good soil fertility though, turf health deteriorates and the grasses become more susceptible to other issues including pest and disease. Some cultivars require less fertile conditions than others. Choose cultivars  that fit with the existing soil fertility and with the management practices that are likely to be used.

Disease and Pest Potential

Cultivars vary in susceptibility to diseases and pests; and the prevalence of pests and diseases will vary according to the climate, locality and management practices. You should be aware of the likely pest and disease challenges in the situation at hand; then choose both cultivars and manage3ment practices to fit.

Mowing quality

Consider if the cultivar will cut clean or is it likely to tear, bruise or sometimes not cut. Different cultivars produce different characteristics in the leaves. Some are stiff, others soft; some have very tough, wiry, thick leaves; and others are quite different. Some produce lots of individual leaves right from the base of the plant, while others grow stems that only start producing leaves higher up.
For some grasses, mowing needs to be with a reel type mower to get a clean cut, while others will cut cleanly with a rotary mower. Some may cut clean in the wet, and others only when dry. Some types of grasses may only cut clean with a mower blade that is very sharp, and some may always have some tearing or bruising.

Mowing height adaptability

The height at which you cut a turf will depend upon what you are using the turf for, and the cultivars that are growing in that turf.
Recommended heights are dependent upon a range of considerations including: type of mower being used, frequency of mowing, growth habit of turf (vertical or horizontal), sward density, strength in leaf,  height of the cultivar, ability to recover from cutting, and other factors. For example, greens need to be cut very low without affecting plant health.

Thatching tendency


Thatch refers to a layer of vegetative (grass) material that develops above the soil, creating a thick spongy surface. This layer can become problematic over time, and with some grass cultivars, may eventually become a barrier to the soil and roots. If thatch builds too much it needs to be periodically removed (ie. by dethatching). Some grass cultivars do not develop thatch problems, others build up thatch slowly. Some are prone to develop thatch fast; requiring extra and frequent work to dethatch. Those cultivars may however present other benefits, which could make them a good choice despite the extra work.

Ball Performance
Ball performance refers to the way a ball acts on a turf surface. In cricket or tennis this will mean whether it bounces more or less, and whether the bounce affects the direction or speed the ball is travelling. For croquet, lawn bowls and golf, the way in which a ball rolls is critical to the game. The speed at which a ball rolls on a fine sports turf can be critical to a game. Championship golf in particular considers ball speed very important; and this can vary significantly according to the type of turfgrass used.

Traffic resistance

This is how much wear and tear the grass can withstand before it becomes significantly damaged, and beyond that, how quickly it deteriorates with further use.

Soil compaction resistance

This is different to traffic resistance. Traffic resistance considers damage to the living grass plant. Soil compaction resistance considers damage to the physical structure of the non living soil.
Soil compaction happens due to foot traffic, and also cultural practices including rolling (eg. Used to flatten a turf wicket or bowling green before play); mowing, or using other equipment and machinery (eg. tractors, golf buggies, and even wheelbarrows. Some grasses do not suffer much in compacted soils, others may deteriorate rapidly.

Recuperative ability

Will the cultivar regrow quickly if it is damaged? If damage is likely to occur, and fast recuperation is critical (eg. on a sports ground); your choice of cultivar may give importance to this factor.

THESE ARE THE THINGS YOU WILL LEARN FROM THIS COURSE

Completing this course will greatly improve your awareness and appreciation of the differences between turf grass varieties, and in doing so, build a vastly improved capacity to select and cultivate a better turf.

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