For Forks Sake

‘Dr. Kris,

I’m sure grass should be easy to grow I see it growing well everywhere except for in my garden. I only have a small patch of lawn with buffalo grass and it’s a constant struggle, even though I was told it is the easiest to grow, apparently not for me! A few months ago it was very dry and patchy and everyone said it needs more water and now after the rain it’s so wet I think I can see some sort of moss algae growing in it. The grass just doesn’t look good, it’s sparse and wilted but it has plenty of water from the rainfall which seems counterintuitive to me. Plants I thought would be hard too grow like cordyline and birds nest fern are easy, but as for the grass I have no idea where I have gone wrong? Any ideas?

Ed, Jimbaran.


Growing a beautiful green lawn which seems simple at first glance, has confounded many a dedicated gardener throughout the ages. You would think it easy given that grass covers 1/5 of earths land surface, from chilly tundra to warm tropics, flooded wetlands and dry deserts, lawns to bamboo and wheat to rice…yes grass seems to grow well everywhere, except in our backyards sometimes.

Buffalo grass is a great all rounder for growing a lawn. It forms a hardy dense cross textured lawn that will cope in a variety of soil types from sandy to clay, also a wide range of climactic conditions, from cool to warm climates and even tolerate some shade. It easily spreads via runners and once established even the most vigorous weeds will have a tough time invading. Well cared for buffalo grass will choke out most weeds giving them a hard time getting a foothold in the first place. Perhaps the biggest benefit is its slow growing nature meaning less mowing and edging than other varieties.

No matter which grass you choose it is still a plant just like any other, you still have to battle the natural elements, the weeds, kids, dogs, grubs and even the soil type. Even if you have all of that covered you look across the neighbors fence and their grass is greener…oh it seems like it never ends, fortunately gardening doesn’t!

Getting to the problem, it sounds like you have waterlogged clay soil. Clay is naturally compact with tiny pore spaces which makes it difficult for water to easily penetrate through to the deeper subsoil. Grass likes water but it doesn’t like to have constantly wet feet, unless of course it’s rice that you’re trying to grow. Any type of soil is susceptible to compaction   over time wih heavy rain and constant foot traffic but with clay soil you’re already starting behind the eight ball. The foundation for a good lawn is the soil in which it grows.

A waterlogged lawn is susceptible to root rot. Once grass is stressed it will appear sparse and thin, it is at this stage that the weeds will move in, and if moist enough algae and moss also. The combination of a constantly damp humid environment with sunlight is enough to promote their growth in your lawn.

So now you’re batttling two problems the waterlogged soil and the moss and algae.


Get Forking

The first step is to aerate the lawn to allow the pooling water trapped at the surface to run-off and give your lawn some relief. Use a garden fork to loosen and aerate it. Fork around the lawn and work in some compost at the same time sprinkling it over the top soil. Clay is mineral rich but if you don’t break up the compacted surface then nothing will grow easily.

If your clay soil is extremely heavy an addition of gypsum around the place will help. Gypsum is a white/grey mineral known as a clay breaker because it improves the physical condition of heavy clay soil.The result is better drainage and root penetration. Uptake of other nutrients will also be assisted by the calcium content of the gypsum.

Generally, gypsum is best mixed into clay or heavy soils prior to laying turf. For an existing lawn that is suffering from compaction on clay, using gypsum can still help. First aerate the lawn with a fork, then spread 1kg of gypsum per sq/m and rake in. If the soil is dry, water after applying gypsum.

Remember good soil structure will give you a great lawn. Moss and algae thrive in wet and humid conditions and in compacted soils with thin turf. An aerated soil will drain well, promote root development, attracts worms and facilitates the absorption of atmospheric nitrogen into the soil. The best soil is loose with abundant organic matter, and has a texture that holds moisture well, yet drains easily. A waterlogged soil is a compacted soil, it won’t allow water to drain freely. If healthy soil is the most important ingredient, water is the most common problem.

If you give the garden a good forking regularly thrown in with a sprinkling of compost and gypsum you should notice an improvement in water drainage, and a gradual recovery of the grass as well as the eradiction of the algae and moss. If the clay is just too hard packed and your making no progress it may be easier to strip the lawn bare and start from scratch, reworking the soil with gypsum and compost and then re-turf the grass.


Extra Tips

– Most turf grasses are sun-lovers so in heavily shaded areas it may be better to select another type of ornamental grass or ground cover otherwise trim the trees.

– Don’t over water, the soil needs to have periods of dry so that the roots will search deeper within it, becoming well rooted in the process.

– If it’s been raining don’t water the grass.

– Take care with the mower. Never remove more than one-third of the green leaf blade at any one time. This can weaken the grass and cause it to dry out easily on hot days.

The grass can be greener on this side of the fence, if only you’d get forking for forks sake 😉


Dr. Kris

Garden Doctor



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