Stump fallen out of a steep bank

I have an almost sheer bank just above my driveway, which leads up to a steep slope above (near 20%), a piece of former hay meadow (so extremely diverse). The sheer part / ridge of the slope has about 6/7 substantial trees growing out of it, mainly oaks that have been there I would estimate for over 40 years given their size. There are two stumps of former trees also in the bank and in the last week, one of them has come down. I have taken some images attached here, but very keen to know what best to do here if anyone can give any advice?

My concern is that this has in some way weakened the whole bank in this section and as such, I'm at risk of a much greater slip. Or (I hope) it could be no big deal, remove the stump and process into use somewhere and move on.

If I can manage with planting or leaving alone, rather than having to build massive retaining walls or something, that is of course my preferred option. Its stood for a long time as is.

Any thoughts greatly appreciated.

Unless the stump is actually in the driveway, or likely to roll into it under it's own momentum, the easiest thing to do is simply leave it.  If it's at rest where it is, it will slow down further erosion from above, and give you time to plant up any bare soil left from the tumble. I would get some quick-growing trees and shrubs into place, so that new roots will bind the bank from further erosion.

Alder Burns wrote:Unless the stump is actually in the driveway, or likely to roll into it under it's own momentum, the easiest thing to do is simply leave it.  If it's at rest where it is, it will slow down further erosion from above, and give you time to plant up any bare soil left from the tumble. I would get some quick-growing trees and shrubs into place, so that new roots will bind the bank from further erosion.

Thank you - its not gotten that far yet - agreed its easiest to leave it. Its currently still attached though, so maybe I need to release it, see where it settles and leave it there. Any view on the sorts of tress and shrubs that might suit a 90° planting in zone 9?

@ MJ....You will need to be more specific as to location to solicit advice about plant species.  Zone 9 in California or Arizona is entirely different than the same zone in Florida (much less elsewhere in the world!)  Especially in unirrigated situations, the selection of plants will be almost completely different.

Alder Burns wrote:@ MJ....You will need to be more specific as to location to solicit advice about plant species.  Zone 9 in California or Arizona is entirely different than the same zone in Florida (much less elsewhere in the world!)  Especially in unirrigated situations, the selection of plants will be almost completely different.

Apologies, South West UK - not the US. Fairly close to the coast, in a valley.

Mj, can you get to the top of that steep bank and check for erosion?  Or at least a good 6 or 7 meters above where those stumps are to check for erosion?  

Did the stump move because it's rotting?  Or did it move because it slid on saturated soil?  

Is there water on your driveway or at the base of that steep bank that is run-off?    

If you stabbbed at the stump with something heavy sharp, like a tire iron, would it fall apart?  

Erosion is probably more of a concern in the long run, although a stump coming down into the driveway is not impossible.  If there is run-off water or spring water above the stumps it should be diverted, probably with the help or advice of an engineer as to whether it should be guided into a pipe that takes it safely down, or drains above that send the water away from the bank, or plant some kind of plant with deep roots that can grow in damp soil that will hold that hillside back.

The planting of those big oaks may have been an attempted solution to try to dry that hillside out.   If you go for the planting-to-stop-erosion, look for deeply-rooted shrubs that if they die or come down they won't present even more work.  It may be that the embankment just can't hold up the weight of those heavy trees.

Cristo Balete wrote:Mj, can you get to the top of that steep bank and check for erosion?  Or at least a good 6 or 7 meters above where those stumps are to check for erosion?  

Did the stump move because it's rotting?  Or did it move because it slid on saturated soil?  

Is there water on your driveway or at the base of that steep bank that is run-off?    

If you stabbbed at the stump with something heavy sharp, like a tire iron, would it fall apart?  

Erosion is probably more of a concern in the long run, although a stump coming down into the driveway is not impossible.  If there is run-off water or spring water above the stumps it should be diverted, probably with the help or advice of an engineer as to whether it should be guided into a pipe that takes it safely down, or drains above that send the water away from the bank, or plant some kind of plant with deep roots that can grow in damp soil that will hold that hillside back.

Hi Cristo,

The stump is certainly rotted out and currently only held up by the ivy stems living on it. No standing water or anything like that on the driveway so I'm not concerned that there has been excessive movement in that form. I've attached two images of immediately above the stump. There does appear to be a little movement possibly, although I can't say with conviction that this is new. There is a trodden path here as well and I sense no change in the terrain under foot.

In the winter there is a trickle that appears out the side of this bank, but thats tiny and about 30ft away, at ground level. I've not been able to trace it back to source.

The water must be what the oak trees are tapping into.  Maybe with the dead ones out of the way the others will have less stress and do just fine.  It doesn't look like any kind of major erosion problem.

Often when oak trees go over, other oak trees start up in their composted leftovers.  That's called a Nurse Log.  So oaks and other plants are perfectly happy to grow among their composted remains.