Water, water and more water. They are heavy drinkers anyway, and now the tree's ability to take in water is hugely reduced.

had about 50% of its roots amputated - a little within the outer drip line

==>>> what does that mean .... how far from the trunk ???? ... when the trench was dug... were there large roots cut.. or mostly small??? .. did you snap any pix????

what i dont get.. is to remove half the root mass ... i would think you would have to trench right next to the trunk .... but thats not what you seem to say ....

how close to the house.. how tall .... is it in wind?? ... etc ...

ken

Like Sara Malone Zone 9b said, water it. Water it through summer droughts the first couple seasons.

Make sure no dirt was piled around the trunk. Try to minimize the amount of heavy equipment parking or driving on the rest of it's root system, as well as foot traffic. Cover any newly exposed roots with a THIN layer of soil.

Thanks for the thoughts.

What I meant by "just inside the drip line" is that it was maybe 6-9 feet from the trunk, but within the zone that is covered by the outermost reach of the tree's branches. Hope that makes it clearer?! The trench is very deep so all roots were cut. The tree is about 20-30 feet from the house. Wind is not a major issue.

How much should I be watering?
Do I water with a sprinkler so that the soil on the entire under side of the leaves is wet or just closer to the trunk ie how much sweep to the sprinkler?
When should I start watering?

For most trees I'd say 9 feet from the trunk should be fine...but beech are notoriously sensitive.

I'd water just within the drip line on the side where the roots weren't cut. You don't want to rot the trunk. The roots should be able to get the water from anywhere within the drip line. Is the tree near a road? The root system isn't necessarily symmetrical...if it is near a road most of the roots will be on the side away from the road.

Water deeply and occasionally. Water whenever the weather reports say there is a drought or a heat wave. Stick your fingers in the soil and if it feels dry a couple inches down water it. Maybe water when the leaves start coming out. Don't necessarily water right now.

how old is this tree??? .... that the canopy is so small ....

imo.. there is a big difference between trenching near a 100 year old grand dad.. or trenching near a tree that was planted a few years ago ...

ken

OK, I've measured. The crown diameter is 40 feet and the trunk diameter is 13 inches.
The trench begins 7-8 feet from the trunk.

Is it near as road? Is there anything that would block the roots in one particular direction?

No nothing else blocking the roots.

Can you post a picture of the tree at the base where it meets the soil?

How recently was this done? I was playing with google. One source recommended you make sure the roots are cut cleanly as opposed to torn. Probably not worth digging them up again if the trench was already filled in.

Yes, running the trench 7 ft. from the trunk may kill it. Not sure watering the remaining half is going to be able to make up for this - time will tell.

It really depends on the plant. Various trees of lesser nobility (har har) would hardly be set back by that sort of thing. The rest of the root system would pick up the slack. But yes, beeches are sensitive.

Since this is done and you can't do anything about it, just water the bejesus out of it and keep your fingers crossed.