Planting trees

[Jack.P]

Hi again .

I would appreciate any advice about planting mature Portuguese laurel trees 4m in height .

The area where they will planted has really heavy thick clay soil with very limited drainage (new build houses).So far I have taken out 2 tons of the rubbish clay and left a trench which after a few days of rain turned into a river .

anyway there isn't really space for conventional soakaway which was my first idea .I am thinking now about drilling about 10 15cm diameter holes at a depth of 1.5 m in the trench then filled with fine grit to aid drainage then a layer of grit at the bottom of the trench with a sandy loam soil mix then with topsoil on top .has anyone had similar problems on a job ? I'm still not convinced it will work or the tree roots will spread outside of the trench in surrounding heavy clay .laurels are hardy though so we've got a chance but any thoughts would be great 

[dumper]

I would not drill holes the drill will smear the clay and they will fill up with water , I would put a layer of stone in the bottom then put in the trees packing them in well with a good natural loam not one of the manufactured shite topsoils that seem all the rage water pipe to the roots and try to leave the surface flat or slightly raised to shed the water, planted a few golf course like this they seem to survive educate the client about watering 

[woody paul]

You dug hole and left it is the first problem, is the clay natural or builders just buried it, you may be able to dig through it which would be best answer. 

[Jack.P]

The reason why I dug the 2 ft trench was because I'm going to backfill with well draining topsoil .this could be the builders fault as before the houses were built 5 yrs ago the whole area was mature woodland so should of had a lot of organic matter going into the soil .the area is 10m long x 2ftdepth x 1.5 ft wide .yesterday I ordered half ton of horticultural grit .half ton of extra sandy loam mix and 1 ton loam topsoil .my thoughts were with the holes Idea to backfill them with grit and they might get through the clay layer aswell although this is bit of a experimental thing and could just make it worse 

[aspenarb]

We are in clay here and I replanted lots of Laurel , took the advice of the greenfingered collective here and they have all survived.

 

Bob

 

 

[woody paul]

2 hours ago, Jack.P said:

The reason why I dug the 2 ft trench was because I'm going to backfill with well draining topsoil .this could be the builders fault as before the houses were built 5 yrs ago the whole area was mature woodland so should of had a lot of organic matter going into the soil .the area is 10m long x 2ftdepth x 1.5 ft wide .yesterday I ordered half ton of horticultural grit .half ton of extra sandy loam mix and 1 ton loam topsoil .my thoughts were with the holes Idea to backfill them with grit and they might get through the clay layer aswell although this is bit of a experimental thing and could just make it worse 

As you say hole is like river how is adding well draining soil to hole going to help, will create nice bog garden. 

[Gary Prentice]

I'd try a quick percolation test in a new small test pit, to see how quick, or not, your planting pits, trenches, will naturally drain. 

 

 

[dumper]

Well draining topsoil will make the trench a bog garden make sure the soil is compacted I would use a clay loam and don’t allow water to flow into the trench

[Ruskins Trees]

You have to drain it to somewhere.  A lighter soil found in rootball and backfill mix will cause moisture in the heavier soil to wick across into the lighter soil. It will fill up like a sink and drown (waterlogged soil) the specimens unless they are a species suited to sitting for prolonged time in waterlogged ground.

 

A drainage layer in clay will not  work unless it has somewhere to drain to (no matter how many times landscape architects produce drawings only showing a drainage layer).   

 

A soakaway will not work unless it breaks through the clay and finds a strata that can facilitate drainage.

 

The only option if there is no option to drain is to mound plant*.  Plant above ground (or partly above ground) and bench soil upto the rootballs. This way some of the roots will always be able to breathe (undertake gaseous exchange).  

 

Once did a tree survey in a woodland where all trees (around 200no 80 years old) were planted on 3-4ft mounds all doing well.  The developer had permission to fell most, I wonder how he dealt with the ground prone to waterlogging.              

 

* If you have a slope, just dig french drains to the lower level (or insert sloping land drainage pipes to  the lower level) . 

Edited December 1, 2018 by Ruskins Trees

[drinksloe]

It will all depend how deep the clay layer is and if u can dig/bore throu it.

 

A local golf course had a massive problem with its greens 10 odd years ago and the grass was almost dieing off, and had lost most of their members.

They drilled holes all over the greens (every few meters) think about 6ft deep filled with pea gravel type stuff and topped with just enough soil to take the turf.

Their greens are some of the best in region now and membership is overflowing.

 

Wot u said might work all depends on u getting throu the clay layer and wot is below that.

Sining a pinch well in and giving it a good 'waggle' in a few places see if u can get throu that layer.

 

U either have to get the water away either downhill throu drainage or ur cores or has been said mound ur topsoil up and pack it to try and stop water seeping in in the 1st place.

A lot will depend on the site