Hi Golf and Bundy it is good time for laying turf in Brisbane now our temps aren't far off normal spring temps and you should get a good chance to let the turf establish before we get the warmer weather that can sometimes stress turf.
I'd recommend the following:
- Mow old lawn low
- spray out lawn with round up,
- wait 2 days and irrigate. Irrigate a few more times in the following week to promote weed seeds to germinate.
- wait for 7-14 days for weed seed and spray again
- hire a pedestrian cultivator and cultivate lawn to 100-150mm
- depending on soil type if you want a more level and free draining surface now is the time to incorporate washed river sand (USGA sand) and any other amendments. To work this out do the following
- pH test your soil with a kit from bunnings or get a soil test to see what to incorporate. You want to be around ph 6-7 for most warm season turf. If it is too acid (low ph) which applies to most Australian soils the solution is to add agricultural lime or dolomite. You can also use poultry manure. If it is alkaline and has a high pH you can increase the acidity of your soil by adding things like compost and manures, leaf litter and mulch. Iron chelates works too. In extreme situations, you can use acidifying fertilisers (like ammonium sulfate) - one handful per square metre, once a year. Sulphur works very slowly and you won't notice a change in your pH for about 6 months.
Id recommend 25kg rooster booster or dynamic lifter/100m2 and pure river sand it will get your lawn hopping.
- order the sand and have the amendment ready so that they are at your place on the same weekend that you hire your cultivator.
- to calculate how much sand to order work out where you want your levels for example:
you may have a 10cm drop off paths and want to make your 100m2 lawn level with all of these do the following calculation.
a = Desired height increase - Height of turf (Normally 30-50mm)x Area
b = 30% Sand for compaction and re-levelling
c = a+b (Sand volume to order)
a = 100mm - 30mm * 100 = 70mm (convert to m for m3 values) 70mm = .07m * 100 = 7m3
b = 7m3 x 0.3(30%) = 2.1m3
c = 9.1m3
- Add half the sand and dynamic lifer then cultivate and mix in with your existing site soil.
- Rake to a rough level
- Add second half of sand and dynamic lifter and cultivate and mix in with your existing mix.
- Keep the extra third of the mix aside for final levelling
- Roll and screed to your desired heights using a heavy roller and level lawn or a large wooden screed.
- Irrigate it to complete saturation this will cause the sand to sink and bed in.
- wait for it to dry and add final amount of sand, screed and level and lightly rake for a fluffly appearance on the sand surface.
- Don't worry if you have sand left over save it for later for topdressing in seam lines etc.
- Lay turf: I'd recommend any of the following Green Couches: Santa Ana, Agridark, Tifsport, Grand Prix, OzTuff or Qld Blue couch (not a green couch) if you don't want the invasiveness for your garden beds. You could always wait a few years for TifGrand and TifTuf although I can't see them getting released commercially for 3-4 years.
N.B. with any soil addition make sure you cultivate them and mix them as not to get a perched layer and any unusual problems that come with soil layering.
Live the turfies dream and reap the rewards of getting your base right.
Cheers
