Need advice on leaning tree

[Stake]

Hi,

I was hoping I can get some helpful input from experienced people here to make the proper decision regarding this tree that is shared between me and my neighbor's front yard. The tree is a Raywood Ash that was planted about 10years ago by the developers. The tree started to lean noticeably about 4 years ago and I think it is still progressing slowly every year.

My neighbor has left me to decide on what to do with the tree. I need to know if this tree appears to be in serious danger of eventually falling soon (hoping you can tell by the pictures) that it needs to be removed as soon as possible before leaves start to grow again and before it encounters the strong winds of autumn. Or is it possible to save/keep it and prevent it from leaning more by regular proper pruning or some other means?

I have no idea how strong the root system of the tree is at this time so I am getting more concerned of the possibility of it falling as there is always now a vehicle parked by the sidewalk that is in the direction in which the tree leans towards to and a green plastic electrical box covering cables in the ground is located a few feet from its trunk. Matching the level of my worry, I am also hopeful that this tree can be kept and somehow eliminate the danger of it falling.

Thank you in advance.

 

[CacaoBoy]

I do not have any personal experience with Raywood Ash, but seemingly reputable sources encourage aggressive pruning while the trees are dormant in winter. See https://www.gardeningknowhow.com/ornamental/trees/ash/pruning-ash-trees.htm It would have been good to have started training it with pruning years ago.

Since you would like to keep this tree, I'd take it back to the point marked with the red line this year and maybe take about half the height off the remaining branches, and cut back to the green line next winter. You might be okay to cut it back to the point marked in green immediately, but I tend to like to prune in stages, and it may be late in the season to prune as much as this tree needs. I did find a warning: "Don't prune the raywood ash between mid-March and the end of June. The ash borer is most active during that period and is attracted to pruning cuts. Avoid all large pruning wounds at any time of year to best protect your ash tree from this dangerous pest." If you wait for the optimum pruning time of next winter, the tree may have fallen or blown over since you indicate that strong winds can be expected in autumn. So you you need to balance the risk that the tree would be injured and die due to late pruning done now against the risk the tree will fall/blow over and die. Your decision may depend on whether it is your vehicle or a neighbor's that is normally parked in the danger zone.

 

[Stake]

Thank you so much for the quick, comprehensive and very helpful reply. Truly appreciate the detailed response including the links you provided.

I guess I'm in a predicament but glad to be more informed. I do regret not having dealt with this problem earlier with my previous neighbor. Not knowing anything about this stuff, I guess we thought the tree was eventually gonna stop leaning or will grow strong enough that it will not be affected by it.

I have previously contacted a couple of tree service company before but they couldn't give me real info on how to address the problem as they said it's already a big tree and mainly offered tree cutting service.

Thank you once again for the help.

 

[BC WetCoast]

That looks like rotational failure to me (the root ball is rotating as a whole in the soil as opposed to a hinge failure where one side of the root wad lifts up but the other side stays connected). I would suggest you get some stout timbers (ie landscape ties) and make a prop to support the tree on the low side. Then next dormant season, prune the weight out of the low side. Personally, I wouldn't go as low as CaocaoBoy's green line, but that's what make some parts of arboriculture an art rather than a science. Who's to say who is right?

 

[Stake]

Thank you for your recommendations! The use of wood to support the tree did enter my mind a few times before but I wasn't sure it would help and didn't know correct materials to use. These information are helpful.