20yr old, 6ft Aralia is suddenly dropping lots of it’s leaves. I’d say 50% so far. The leaves are falling off still green. Plant has been in same spot for 6yrs, nothing changed in heat/ac/humidity from any other winter. I don’t see any bugs, blight, fungus etc.
What to do please? Only plan I have is to take it outside and repot in new soil, deciding on pot size once I see roots. I have never pruned it at all and am afraid to do so drastically.
I hope you have not yet repotted or taken it outside in temperatures below 60 degrees.
Ming Aralia roots are very sensitive to moisture around them. If the roots get too dry for even a short time, the plant reacts by producing a flush of yellow leaves. Likewise, if the soil is kept constantly wet, then some of the roots will start to rot and leaf loss will be the same. It is sometimes hard to tell whether you have under or over watered because the symptoms are similar. After an initial loss of leaves, once the watering gets under control, the leaf loss will stop and healthy new leaf growth will emerge. Use your finger to probe the soil and try to get your watering back to what it was before the leaf loss.
Older plants never need repotting and it is best not to disturb the roots. That is why I advise against repotting. Mings are also quite temperature sensitive so I also advise against taking it outside even for a short period. Make sure it is not exposed to any cold drafts when indoors.