Question
Hi Long Island Gardener,

Thanks for your fast and helpfull answer.

A little bit of history: When I started out last year as a complete greenhorn, I listened to father in laws adice: Grass grows anywhere. And so I threw the seeds onto the soil without further thinking or questioning. The the problems came up,,,,,,,and I started to read and learn,,,,,Inspired by what磗 going on with 搊rganic gardening?in the US,  I decided to try it,,,,the alfalfa pellets were not easy to get though,,,I finally bought them in Germany (see how international gardening can get ! ?) where they sell them as food for horses that need an extra punch to win the next race ;-)
All around me here in France people still spray herbicides and use chemical fertilizers. Too bad.

Actually a soiltest is on the way厖 however it is a rather basic one: pH, N, P, K, Mg and I think that is pretty it.
It is not as sophisticated as the bacteria counts of Dr. Ingham.
Is it worth to spend the ~90€ to get the bacteria and fungi analyzed as well?

Clay and Sand is indeed the recipe for nightmares!  In fact if the sun shines and no tall grass shades the soil you have difficulties to crack the surface with a screwdriver after a couple of days. In return, once wet, you sink in fully with your shoes and its hard to get them out again.

You asked about what grass I grow on the downhill slope. I ll use the latin naming as I am not fully familiar with the English naming.
It抯 a mix of:
20% Lolium p. (var: Barcredo)
20% Lolium p. (var: Titus)
15% Festuca rubra.commutata (var: Bargreen)
10% Festuca rubra rubra (var. Salsa)
15% Festuca rubra trichophylla (var: Barcrown)
5%   Poa pratensis (var: Solo)

I bought it directly from the factory (a dutch company, specialized in grass and offering a high variety from various golf turfs up to football arenas but as well mixes for biotopes).However, not sure whether all the above survived the soggy state during the autumn and winter. It looks to me as one (or max two) varieties made it.

When we passed the roto-tile machine I actually did barely see a worm. Might be that they are in deeper layers as it was rather warm and the first 10cm dry and hard. Or maybe that is because they did not have any organic stuff to eat and the soil is simply unattractive. However in the back of the garden, under 8 old trees with nice dark ground, I can see the little 揾ills?the worms leave especially after a rain.
Behind the house I did not dig in any compost,,,, only top-dressed a layer onto the existing lawn. On the right side of the house (no turf yet) I tiled in ca 6 cm of compost. I hope that will make a nice home for worms,,,,

Any advice on the overseeding procedure? Do I need a special 搊verseed ?mix?that germinates faster to not be shaded out by the other grass? The above company offers that but it only contains Lolium p. (var: Titus), covered with a germinating-aid.

Next question: I mentioned the old trees. They are 損rotected? - no right to touch them. Anyway,  I like them,,,,,,, our 搇ittle forest?is a nice spot when it is really hot and you hardly can stay on the terrace.
So I wonder what will grow below those trees. I ll try the above mix maybe the 5% Poa Pratensis will make it there. Otherwise, what could I do with that space ?  Between those trees is a really wet spot ?I dig a hoe and it will fill with water.

About aerating. I could rent a hollow-spike aerator for 70€/day (again in Germany). When is it best to pass it? With what should I fill the holes? I thought about a mix of compost and sharp sand?Basically that is the only way I will get any organic material into that mud soil without to destroy and restart the lawn. Right?

Have a nice Sunday !
 Dirk


Answer
Your Grass translation:

L. perenne - Perennial Ryegrass.
F. rubra - Red Fescue.
P. pratensis - Bluegrass.

Since we're starting with the basics, the ultra-soiltest is probably over the top.  In a Lawn, you want a Bacterially dominated soil.  But we're first and foremost concerned about the minerals there.  So let's do one thing at a time.  When you get that 'Basic' test back, see what's there, and what isn't.  Hopefully it will also include things like pH, Cation Exchange statistics, tilth/composition, and salt content and electroconductivity.  You need to know how much Clay is in your soil and whether it's brimming with fertilizer Salts or some alien materials before you proceed here.

Do they mow Lawns in France?  Seems if they have aerators for rent they would have Lawnmowers.  The concept of a Lawn is very English.  I am wondering how the French Gallicize that.

Trees are going to need a groundcover.  The best Grass will not look as good as the best groundcover.  What kinds of things do the best looking houses grow under their Trees?  Is it Grass?  Here on Long Island, it's Pachysandra, with Azaleas and Hostas in the shade of the canopy.

If the USDA looked at your weather, Dirk, what Zone would they give it?  Any clue what City(ies) most closely match your climate?

When you 'dig a hole' behind the Trees, are you saying that there's water there already?  Or are you saying you can fill the hole with water, and it will keep the water?  Literally, how long do you think it takes for that water to disappear from a hole there?  We need to know your drainage situation.  Same details needed for the rest of your property.

What kind of Trees?  French or English is fine, I'll just Babelfish the translation.

I suspect you have a high Clay soil that's become seriously compacted, very Earthworm-unfriendly, little biomass in that soil, no future without intervention which is what you're doing now.  High Fungal population esp under the Trees, except where you Rototilled in which case that region is devoid of all life period.  FYI: Rototilling frazzles the Earthworms; when you do it again, do a very rough job that leaves chunks of soil intact. It used to be at the top of the list, now we do it as little as possible.  More FYI: Fungal population would be nice to have, it's better than nothing.

Do you have a source of free manure in that French countryside with horses eating Alfalfa?  Some communities here mandate that the manure be hauled away and the people are only too happy to make it available on Craigslist.  Do you know what Craigslist is over there?  Has Craig opened in France yet?  I'm just trying to get an idea of what resources you have so that when the test is back you can proceed posthaste.

Sand is not Organic material.  I know you know that, but you already have it on your list, and if you have Clay, with your current parking lot, you are going to make it tough enough for Tanks to roll across if you add Sand.  Manure and Compost, Earthworms and other creatures, even Birds and Squirrels will put life back into that soil -- the kind of life that jumpstarts your Soil Foodweb.  If you can, get a book called 'Teaming With Microbes'.  I hate the title, but it's written by a team of garden writers who converted to Organic after seeing electron microscope images of nematodes or something attacking a pathogen in someone's backyard soil.  They organize and introduce the basic information a person would need to know to make Intelligent Gardening a sensible and practical option.

So you have some questions on the table, Dirk.  rsvp!  And Happy Thursday!