By Todd Layt
Managing thatch in Sapphire® Buffalo turf is very important for maintenance
Unless you manage your Sapphire® Soft Leaf Buffalo lawn over time, its thatch will increase. It's nothing to worry about though because the dethatching of a lawn is a fairly simple job and can often be a case of simply mowing it short. You’ll need to dethatch your Sapphire Buffalo lawn at least every 2 years.
(Above - Top Dressing Method)
What happens is that over time, Buffalo grass runners (also known as stolons) will grow over the top of each other and eventually smother the runners and leaf underneath. The runners and leaf that are smothered will eventually die off. The dead thatch that is left underneath becomes a real problem.
A thick layer will develop if the lawn is left for many years with out being dethatched which causes a range of problems. In severe cases the lawn can become weak and susceptible to drought, pests, and lawn disease because runners on top of this thatch layer have problems rooting into the ground below. It also makes for a tired looking lawn and reduces new growth (new growth is the sign of a healthy lawn).
What you need to fix this is new growth that grows close to the soil level. Here are the 3 main methods to achieve a nice low thatch Sapphire® Buffalo lawn.
This would have to be the simplest and easiest method and all you do is mow the lawn short once every 2nd spring. If you feel like it you can do this every spring as it will benefit from a yearly short mow. If you choose to do it every spring, the scalping heights won’t need to be quite as low as doing it once every 2 years. Just set your mower to a very low height and scalp your lawn.
Depending on which brand mower you use, the height settings will vary but the main thing you need to pay attention to is making sure there are still runners left covering the ground once you’re done. This is basically a controlled heavy scalping of the lawn. All the clippings need to be collected and the easiest way is to mow one time at a slightly shorter setting than you’d normally use with the catcher on to collect the clippings.
Then mow it again right away but this time lowering the mower’s height to a level where you can actually see a small amount of dirt showing through the runners. Make sure that there a lot of runners still crisscrossing the ground. After you’ve scalped your lawn fertilise it with slow release fertiliser and water it well for the next 2 to 3 weeks.
This is optional but an even better method is for you to fertilise your lawn with slow release fertiliser 4 weeks before scalping. What this does is gets your lawn actively growing and makes it reshoot quicker after scalping. (If you do this every year what you’ll find is you wont’ need to scalp it as heavily or mow it as low as compared to doing it every 2 years, and the scalped look will only be there for about 10 days or so.
The best time to do this is Mid-September in Queensland and Northern NSW, and early October for Sydney and Perth, and Mid-October for Melbourne and Adelaide.
It’s recommended to use a pre-emergent on the lawn if you have a weedy lawn and the only one that is available to the general public is called Oxa Pro. This has a combination of slow release and Oxadiazon. Apply this after scalping the lawn and water it in well.
What do I do if I have an older lawn and the thatch is really bad?
If the thatch level is really high because you haven’t mown your lawn short for many years, you might need to gradually lower the height of your lawn over a month or so. In a very high thatch Sapphire® Buffalo lawn, the runners on top may not be reaching the soil below, and may actually be rooted into the thatch. The runners below that top level can actually be very weak, and the runners at the bottom of the lawn can even be dead.
If this is the case you’ll need to remove the top layer while leaving the layer below (Middle Layer) in tact to reshoot and root out into the soil which should happen in about a month or two. By this time some of the dead looking bottom runners should have reshoot, and some of the mid layer runners that you have rejuvenated will have grown down a bit and rooted into the ground. When your lawn looks healthy again, you can take it down another level or two on your mower to remove some of the middle layer of thatch, exposing the bottom layer.
Remember to always collect the clippings. Re-apply another application of slow release fertiliser after the second short mowing if the fertiliser is running out. Water well for a few weeks, and you will have a rejuvenated lawn.
Using a dethatching machine.
As Sapphire® Soft Leaf Buffalo (and all Buffalo grass for that matter) doesn’t have underground runners (rhizomes) this method is not as critical for Buffalo as it would be for Couch or Kikuyu.
A mower will work almost as well as a dethatching machine but dethatching machines are still suitable for Buffalo turf as long as you don’t dethatch to soil level. If you go too low and remove all of the above ground runners you might lose your lawn. So when you’re using one of these machines, make sure you can still see some runners crisscrossing the ground.
Same goes for the first method. Remove the dethatched grass and take it away. Fertilise as per the first method, and use a pre-emergent if you have a weedy lawn. If it is a very old Buffalo lawn that has very high thatch you may still need to dethatch twice, removing half the first time, and the rest the next time, so it may be easier to use your mower rather than hiring a specialised machine twice.
Top dressing works particularly well for very old Buffalo lawns with very high thatch. As long as the level of the lawn isn’t already too high it’s a great way to rejuvenate your Buffalo lawn no matter how heavily thatched.
Buy organic sandy loam top dressing mix from your local supplier. Simply spread the mix over the top of the lawn. How high depends on the thatch level of your lawn, but a good rule of thumb is to spread the mix over your lawn with a shovel, then rake it out so some of the leaves are still showing.
Important! If no leaves are showing you may have gone too deep and this can smother the lawn. As long as you have leaves showing you will be fine.
Applying slow release fertiliser before topdressing (having it below the top dressing mix) really helps the lawn. It is recommended to top dress at least every 3 years provided the level of the lawn isn’t too high above paths or drainage points. Top Dressing is also great at fixing undulations and uneven parts of the lawn.
Combination of methods.
Using method 1 (the mower method) for two years in a row and then topdressing your lawn every third year is a great combination method. Every third year you’re getting organics into your lawn which really helps the lawn quality. It also reduces the amount of work required, as it is easier to scalp the lawn two years in a row, then top dress every third year.
When buying a mower for future dethatching.
Make sure it has a catcher, and it has some lower settings on the mower. Honda Mowers for example have really good lower mowing heights. Also sharpening the blades, or putting on new blades before scalping or dethatching will give you a cleaner cut.