Planting in heavily compacted soil

[onetruth]

I need to plant around 100 trees near a recently enlarged pond.  The ground has suffered severe compaction by JCBs and the like, and it's possible that much of the top layer was originally the subsoil.  It's bad - no air pockets, no worms, not much discernible organic matter.  It's been water-logged since the works were carried out.  I'll be planting oak, birch, holly, hawthorn, etc.  

 

What's the best way for me to go about this?

 

I'm inclined to dig fairly large pits (maybe 50cm dia x 50 cm deep), use container-grown stock, add a bit of bone meal, and buy in compost for the backfill.  I'm slightly worried that these pits will just act like buckets and cause the roots to rot away.  

 

I also wonder if importing earthworms and/or mycorrhizae to the site would make a difference.

 

Personally, I'd rather dig the holes and add the goodies this year, and plant up next, but my customer is keen to get the trees in as soon as possible. 

[difflock]

Sounds like a Council job, from personal experience.

And I agree about the pits becoming buckets.

Any possibility of getting a farmer/contractor in to "rip" , i.e. the affected area, which ripping, if untrafficed after, might provide some drainage, but is there any gradient to let the water away?

Other possibility

Does the surface need to be kept "flat", i.e. can you import proper soil/planting material and provide mounds to allow for drainage?

or

Perhaps plant, Alder and Goat Willow type species, which will thrive in such unfavourable conditions.

P.S.

What size of trees, surely slips would be better?

mth

 

Edited April 5, 2018 by difflock

[Khriss]

Def rip or rotavate. Pity the guys with digger have left or they could have assisted. Mulch will bring back the worms, soil type could be crucial ( heavy clay ?) K

[Martin du Preez]

Get a farmer to drag a subsoiler in then plough or top down some mulch in?

[Rushes]

If it is subsoil then you need to bring the soil to life. It will need a solid lump of topsoil / muck heap on top and ideally a year of growing anything that will to bring life to the soil - usually annual deep rooted crops that will break up the pan.

 

You can try and build a hole that has good stuff in it that will feed the tree for a year or two, but if you don't attend to the soil then you are trying to grow trees in a pocket of goodness encased by dead matter - think a clay pot. Look to the soil, until you see worms / fungus you don't have a place to plant a tree to survive.

 

If it's on a price - stick them in but don't offer a guarantee for replacement without the previous treatment.