Help,

Last night i watered my elm. I have the pot in a shallow tray. Heres the problem. The tray filled. and it was above the drain holes it sat like that for about 17 hours the bottom of the pot was saturated. when i lifted the tree out to see the damage. unfortunately, the roots had grown in to the bottom of the pot. So there were submerged too. i did the only thing i could think and cut the long roots" that where two extended any way," and some of the finer ones that where obviously under water.

How long can a Ehinese elm be under water. before root rot sets in??

Did i take the right preventive action.

Some one please let me know!!!!