Soil rehabilitation- not just top dressing

[u/confusedham]

So, long story to read. I am a gardener, and love plants but never cared about lawns. Always saw perfect lawns as a waste of water in the past.

I rehabilitated my mother in law's grass over a 2 year period making the soil heathy again, in 4 years I haven't made a dent in mine. I decided to take radical steps finally. Doing half my backyard at a time, mostly because I'm still midway through building a very obscene cubby house.

Location

NSW, south south west Sydney.

Current soil state

Clay base, and about 2-3 inches of absolutely spent hydrophobic cigar ash as soil. Zero life left, and ph tested today averaging 5 with several locations pushing 4. Free draining but zero retention.

Method so far

I've just come out of a winter where I dethatched and grew green fertilizer as an attempt at bringing back organic life to the soil. Didn't take in the backyard but worked well out the front.

I treated for bindi and broadleaf weeds about a month ago, and today I absolutely scalped the crap outta this lawn. Instead of dethatching, since the soil is so cooked I used an Ozito cultivator to start breaking apart the soil. Removing. Thatch and excess runners. I'll be growing a generic hardy mix that has Kikuyu and zoysia in it, so I'm going to leave some in there, if they are dead it's fine they will rot down. It has basically been growing back runners and some rhizomes but failing to keep going due to the harsh environment and lack of life, leading to continuous thatch buildup from runners that start up when it rains then go dormant.

Additives and life

Going to add standard lime in, will have to calculate the right amount to try to gently bring it close to 6 over a 1 year period. It's a rehab, not a quick fix.

Will also be cultivating in plenty of manure, manure compost, coir, soil wetta, blood and bone etc.

I'll probably add some mushroom compost as well for it's alkalinity, and because it usually results in some pretty healthy microbes and fungis growing in the soil. I'll add about half an inch of top dressing over this, spread the hardy grass seed mix and cover that with some more top dressing just to make sure it's got some protection from birds and moisture contact

Going to top all with a thin layer of sugarcane mulch, yeah it's not commonly seen in the burbs but the soil needs it, and the doves here are so dumb they even eat the seed covered with additives.

Wish me luck! Once again it's a long term project, not a quick fix.

Bonus pic: second daughter is due in a couple of days. I planted a Murcott mandarin the day of my first daughter's birth. Now 2.5 years old and it produces great fruit. She helped me pick her sister's plant for next to it, will be a nice Tangerine.

[u/rooshort_toppaddock]

Sure. Rather than digging in, I am layering up. The sand is essential for drainage and structure, and as it doesn't break down it is great for filling low spots. I use a product called "overturf" topdressing from my local landscape supplier. It's a mixed grade sand with organics and chook manure. I'm doing the low and slow method, so I just spread about 5mm across the lawn each time and a bit more in the low spots I'm filling. Then next time I will get a 3 in 1 compost that has cow and chook manure plus mushroom compost and spread 10mm of that around (its a bit harder as you sort of have to smear it on and break up lumps), then next time I will get a composted soil conditioner that is mostly decomposed wood and do a 10mm layer of that. If I can do all 3 in a year I consider it a win, but if budget constraints I just pick one or two. I never do it all at once, that's too much work for my old back.

As for gypsum, once or twice a year I throw about a handful per meter squared down, helps open up the structure of clay and also helps reduce dog pee burn marks. Seaweed I do in a pelletised form like Seamungus a couple of times a year and hose-on every couple of weeks which I sometimes add liquid compost, worm tea, or biological microbe booster to.

Not only is my lawn starting to look good, but I no longer have overly waterlogged slop after the excessive rain, no standing water, and much less mud squelching up through my toes when I walk on it. And in summer it isn't harder than concrete. I think it's worth it just for the soft footfall alone.

[u/tee_stock → u/rooshort_toppaddock]

Mate, thanks so much for this breakdown.

I'm considering purchasing our next family home, but it's in a heavy clay area. You are giving me hope for my lawn and gardens!

Do you have any fruit trees or other trees which you have planted in the ground? Did you also "plant up" on mounds or similar?

[u/rooshort_toppaddock → u/tee_stock]

I've had both, and I'll take clay over sand any day! I've got a lemon and a lime tree in, did plant on mounds for them but also dug out a bit under them and backfilled with rich soil, 18 months on and the lemon produces loads and the lime (6 months) is just coming on, had issues with fungus and pests due to the humidity (west of Brisbane). Have a green and a brown fig in for about 3 months, no mounds but big hole with rich backfill, brown is fruiting and green is getting tall, same pest issues.

My big win is the lady finger bananas I planted to screen out the 2 story neighbours, dug them in and then put some edging around them and I toss my kitchen scraps in there, they have literally gone bananas and hit 5m in 2 years, with delicious fruit.

Did a no-dig garden at back fence as my first project 6ish years ago for tomato's, gooseberries, Rosella's, strawberries etc. Just add a new layer of manure and compost and sugar cane mulch every year before planting, and this is where the worms now live, the soil here is delicious. I popped a purple passionfruit in 2 years ago and I get more fruit than my friends and family can take, lots of community give-away or swaps for those.

In short, clay is great. It holds water (if it isn't hard baked and hydrophobic) and is nutrient rich, it just doesn't like giving up its nutrients or water. So with a little TLC to enable moisture penetration and cation exchange, clay can be a productive garden space. You might get cracks in your house though, not usually a major problem and pretty normal in clay areas.

[u/tee_stock → u/rooshort_toppaddock]

This is exactly what I was hoping to hear. I was apprehensive about clay, but now it seems like it's very achievable.

My last place (Sydney) had a nice loam with some sand, and was very forgiving. I have friends where we want to buy (northern NSW) and the shovel literally bounces off their yard. (New build, compacted clay soil).

Have you had any experience with just dumping woodchips and letting it sit? And maybe growing a green manure through it? I know it's a slower approach, but essentially a no dig. I'm looking at an acreage, and there will be large areas unused for a while, before I will plant. I was thinking of just putting 3-6 inches of fresh woodchip (can get it for free locally) and leaving it for a couple of seasons.

[u/rooshort_toppaddock → u/tee_stock]

New builds are the worst, they sell the topsoil then drive on everything and fill the gaps with KFC buckets, used vapes and monster cans, then throw cheap turf straight on top. First thing I'd do is core aeration in that scenario.

Yeah did the woodchip method and it worked fine, but as you say, slower. Was on warm season grasses so the stolons crept across it pretty quickly, the regrowth was a bit pale until I added some urea, decomposing wood consumes a lot of nitrogen. If you can mound the chips and tarp them they'll break down quicker before spreading. Did some no dig vege beds by starting with chips and green manure over a couple of seasons, was very slow but started showing improvements. That was during the 22 floods though.

If you want to go next level you could plant a crop of daikon to break up the clay, then mow when mature, then plant alfalfa or beans or fenugreek or clover, then whn mature bury that in woodchips and leave for a while then repeat planting of manure crops and layering of chips will get you some gold over time. If you have the space, having a crop can look nice, help the soil and I tell you what, broad beans fresh of the plant are next level delicious!! Rotate the crop around the space and nice grass will follow.