Benefits of Sowing Cool Season Grasses In Autumn

Written by Ian Thompson

Ian holds a Masters in Turf Management from Sydney University, has over 20 years experience working as a golf course Superintendent, turf manager, product formulation and development. We call him our resident Lawn genius.

When it comes to germinating seed we recommend people remember the acronym WOT, as in WOT does it take for seed to grow. Water, Oxygen and Temperature. Temperature is the most commonly overlooked factor and generally the reason for failure when it comes to germinating new seed. In this blog we cover every element of WOT so you can have great success with your seed germination.


When it comes to seed germination light is one of the first things that comes to mind but weirdly, it’s not critical to seed germination. We like to use the acronym WOT to help us remember.


Not surprising of cause that seeds need water. The important part here though is the seed must not be allowed to dry out. Once seed has gotten wet than the processes within that seed have begun, it starts to swell and the first root (radicle) starts to emerge. This means you need to be vigilant in keeping your lawn seed damp when you are trying to germinate it. Watering twice a day just isn’t going to cut it if it dries out in between.


Probably not one most people would guess. The best and most common way to ensure you have oxygen to the seed is to sow it in a new soil that has been loosened up nicely, sowing it in a soil that is hard and compacted will inhibit germination and success.


Not all seeds can be sown all year round and even if you could the challenges of sowing seed in the peak temperatures certainly make it difficult. For lawn seed the best time to sow is in Autumn when soil temperatures are still high enough for seed germination but the temperatures are cooling, moving into a period that is likely to put less stress on our immature grass plants, allowing them to grow and be healthy before the heat of Summer, some 9 months away.


What is a cool season grass?

In Australia many of our grasses are warm season but in the southern states these warm season grasses don’t thrive, particularly in shaded or frost prone environments. So that’s where cool season grasses which operate at lower temperatures and have higher levels of chlorophyll can thrive. In Australia the most common cool season grasses are Fescue, Rye and Bent Grass.


The best time to sow a cool season grass

The best time is Autumn, we still have the temperatures warm enough for good seed germination and establishment but it still gets a full Spring before it has to endure the heat of Summer, this being the most challenging time for a cool season grass.


The ideal Cool Season grass seed

When it comes to cool season grasses we have our favourites for sure. Rye grass in our opinion is a little bit light on colour and a bit to fast grower and bent grass isn’t quite as shade tolerant as we like. That’s why we only have one cool season grass product on offer, Sublime 365 which contains 90% Tall Fescue, this is the most drought tolerant of the cool season grasses, can grow in both full sun and a large amount of shade. While the Tall Fescue is a rhizomatous tall fescue (spreading) we coupled it with Kentucky Blue grass to improve density.


How to sow Sublime 365

Sowing Sublime 365 is easy with the key elements being WOT. Please note that Sublime 365 is a cool season blend not suitable for locations north of NSW.

Prepare the area

The first step in the process is to make sure the area is prepared properly, without a good soil with oxygen you won’t have success. Please do not waste our good seed by simply throwing it on the ground. You can either disturb the existing soil or bring some in for this process.

Sow the seed

Lightly sprinkle the seed around, Sublime 365 needs to be sowed at 5kg/100m2 for a new lawn. It’s best to measure out half this and sow in one direction before sowing the other half at 90 degrees to that one. Be sure not to drop it in clumps and we recommend the use of a spreader for best results. If using a spreader, go around the perimeter first so the seed won6’t land in your garden beds.

A light rake in

Seed should not be left on the surface. If it’s left on the surface it is more prone to birds eating it and drying out, both sure ways to have poor success. Lightly rake in a few directions to help cover the seed. Don’t bury it to deep though, once germinated it can grow up through the soil about 3cm.

Water, water, water

Once you have done all the above it’s time to water the seed. The best way to do this is with a soaker hose or sprinklers on timers. Start by running a cycle to wet the soil and seed thoroughly. Then monitor, once it starts to dry out again turn the sprinklers back on, this will indicate your time in between watering, on hot days this shortens and on cooler overcast days it can be longer. It’s absolutely critical that this is monitored properly, the moment that seed dries out is the moment it dies out.

What next

As the grass germinates and comes through don’t just cut the water off, it’s roots are still very limited and like a baby it still needs some nurturing. Keep the water up but start to run the sprinkler for longer but also make it longer in between run times. Once the seed is up and running a light rate of Lawn Play All-Rounder at 1kg/100m2 can help it establish and start running.

First cut

When seed first germinates it loves to run skyward and the plants are all very individual, once we can start mowing that growth habit changes and the lawn will start to thicken up. The best tip here is to wait until the newly sown lawn is strong enough to tolerate the mower turning on the lawn and for the blades not to be pulled out by the lawn mower. Make sure the cut is nice and high.

What about the weeds in it?

Our seed has been rigorously tested for weed seed and we know its good, unfortunately though with all the water going out on your lawn there is a good chance that any weed seed in the soil will germinate. This may be from the soil that has been there all along or from the soil brought in. We highly recommend that you use a soil (like 80/20) that does not contain organic matter as these products can contain recycled content from your green bins including weed seed.


As always if you have any questions about the suitability of Sublime 365 for your area or advice on soils, seeding or just anything lawn related please feel free to contact us at [email protected]

Sublime 365 Cool Season Grass Seed


9 in stock

Lawn Play All Rounder Lawn Fertiliser


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