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JFGLN
04-26-2011, 01:42 AM
I'm looking for ideas on improving this lawn. Looks like the landscaper applied a thin layer of topsoil over heavy clay. Serious drainage issues. Will topdressing with compost help?

JFGLN
04-26-2011, 01:52 AM
Would it be better to start over. Till in compost 6" deep and reseed? It' a big area, about 8000 sq ft.

RigglePLC
04-26-2011, 10:50 AM
Drainage issues should be solved with drainage. Install 4 inch black plastic slitted drainage tubing underground. At a minimum, French drains filled with rock. Be sure gutters from house go into underground drains leading out to street. Only other solution is to recontour to provide surface drainage. Maybe you need to have a small hill instead of a valley.

Kiril
04-26-2011, 10:58 AM
Would it be better to start over. Till in compost 6" deep and reseed? It' a big area, about 8000 sq ft.

If you are willing to till .... then till it, as this is the only reasonable solution, especially if you are dealing with compaction. Soil test and determine how much compost and whatever other amendments you need so you can get it all done in one shot. Proper soil prep is one of the main points to address when establishing turf .... and all too often it is ignored completely or done wrong. For your reference.

http://www.seattle.gov/util/stellent/groups/public/@spu/@csb/documents/webcontent/ecological_200312021255394.pdf

Kiril
04-26-2011, 11:01 AM
Drainage issues should be solved with drainage. Install 4 inch black plastic slitted drainage tubing underground. At a minimum, French drains filled with rock. Be sure gutters from house go into underground drains leading out to street. Only other solution is to recontour to provide surface drainage. Maybe you need to have a small hill instead of a valley.

That entirely depends on the reason for the lack of drainage. If it is a result of a shallow depth application of topsoil over a compacted clay, then no drainage in the world is going to make it better.

Smallaxe
04-26-2011, 11:09 AM
You said there is a thin layer of topsoil over the clay. How thick is the clay layer?

Tilling in compost is always a good idea, but compost breaks down over time and your soil is back to a platelet structrure.
A sandy compost tilled in thoroughly and deeply, is about the best way to go. If you are able to hit gravel or sand below the clay even better, as it will require less work and material to fix your drainage issue...

Meanwhile mow only when it is dry and allow the soil to dry. Mulch mow and add compost after aeration, which more often the better.

You have a large lawn, only work as much as you can handle with a wheel barrow and regular reartine tiller. Start with the lowest area first and go from there.

If you decide to hotdog it with big bad machines like 'true professionals', your disappoint will continue. Do one spot right and forget about it. A proper lawn with proper soil never needs aerating, unless there is too much traffic, fert, and water... :)

Smallaxe
04-26-2011, 11:17 AM
That entirely depends on the reason for the lack of drainage. If it is a result of a shallow depth application of topsoil over a compacted clay, then no drainage in the world is going to make it better.

That is a good point to keep in mind... Drainage can mean a number of different things, depending on the context... In this case, increasing perculation will help alleviate drainage issues...

Kiril
04-26-2011, 11:19 AM
You said there is a thin layer of topsoil over the clay. How thick is the clay layer?

Tilling in compost is always a good idea, but compost breaks down over time and your soil is back to a platelet structrure.

That is not entirely true. Compost will continue to break down into more stable forms of organic matter which will help keep the soil structure somewhat friable. That said, you need to keep the organic inputs into the system (i.e. your SOM) steady, especially if you are removing clippings, leaves, etc.....

Smallaxe
04-26-2011, 11:26 AM
That entirely depends on the reason for the lack of drainage. If it is a result of a shallow depth application of topsoil over a compacted clay, then no drainage in the world is going to make it better.

Double post because the storm is messing with my satelite connection... :)

Smallaxe
04-26-2011, 11:40 AM
That is not entirely true. Compost will continue to break down into more stable forms of organic matter which will help keep the soil structure somewhat friable. That said, you need to keep the organic inputs into the system (i.e. your SOM) steady, especially if you are removing clippings, leaves, etc.....

I agree... That is true...

However, if you're going through the work of tilling, a sandy compost would be better than a pure compost, IMO...

Another thought occurred to me is: What if th homeowner decided to add 4" of top soil that was High in SOM on top of the clay hardpan... Would that solve his problem?

Kiril
04-26-2011, 11:53 AM
Another thought occurred to me is: What if th homeowner decided to add 4" of top soil that was High in SOM on top of the clay hardpan... Would that solve his problem?

No it won't.

Smallaxe
04-26-2011, 12:15 PM
No it won't.

Again I agree, but it is a common solution in the minds of many an lco... The subject just came up again... :)

JFGLN
04-27-2011, 12:04 AM
If you are willing to till .... then till it, as this is the only reasonable solution, especially if you are dealing with compaction. Soil test and determine how much compost and whatever other amendments you need so you can get it all done in one shot. Proper soil prep is one of the main points to address when establishing turf .... and all too often it is ignored completely or done wrong. For your reference.

http://www.seattle.gov/util/stellent/groups/public/@spu/@csb/documents/webcontent/ecological_200312021255394.pdf

Thanks for the link. I actually have a copy of that paper. It's good to review it occasionally.

JFGLN
04-27-2011, 11:01 AM
You said there is a thin layer of topsoil over the clay. How thick is the clay layer?

Tilling in compost is always a good idea, but compost breaks down over time and your soil is back to a platelet structrure.
A sandy compost tilled in thoroughly and deeply, is about the best way to go. If you are able to hit gravel or sand below the clay even better, as it will require less work and material to fix your drainage issue...

Meanwhile mow only when it is dry and allow the soil to dry. Mulch mow and add compost after aeration, which more often the better.

You have a large lawn, only work as much as you can handle with a wheel barrow and regular reartine tiller. Start with the lowest area first and go from there.

If you decide to hotdog it with big bad machines like 'true professionals', your disappoint will continue. Do one spot right and forget about it. A proper lawn with proper soil never needs aerating, unless there is too much traffic, fert, and water... :)

Not sure how thick the clay is but its defiantly deep. The owner says the landscaper applied 3 to 6 inches of top soil although I dug a couple of test holes and the clay started an inch below the surface.

So my question, Is aeration with a topdress of compost going to help this lawn?

Kiril
04-27-2011, 11:13 AM
Not sure how thick the clay is but its defiantly deep. The owner says the landscaper applied 3 to 6 inches of top soil although I dug a couple of test holes and the clay started an inch below the surface.

So my question, Is aeration with a topdress of compost going to help this lawn?

Is the soil compacted? How deep are you aerating?

If the clay is compacted aeration will not fix the drainage problem. If the clay is not compacted, and you are aerating to a well into the clay, then conditions will improve over time.

You need to map the area for compaction before you can determine what is the appropriate course of action.

.... and buy yourself a soil sampler.

JFGLN
04-27-2011, 11:27 AM
Is the soil compacted? How deep are you aerating?

If the clay is compacted aeration will not fix the drainage problem. If the clay is not compacted, and you are aerating to a well into the clay, then conditions will improve over time.

You need to map the area for compaction before you can determine what is the appropriate course of action.

.... and buy yourself a soil sampler.

How do I tell if the clay is compacted? My aerator pulls plugs about 3" deep.

Smallaxe
04-27-2011, 11:29 AM
If there is no place to 'punch thru' the clay then you are going to have to live on the hardpan... Like starting a lawn on the sidewalk... 3-6 inches of sandy loam, hope for worms and watch the irrigation...

Kiril
04-27-2011, 11:42 AM
How do I tell if the clay is compacted?

Penetrometer.

My aerator pulls plugs about 3" deep.

Not gonna cut it.