rockm
Spuds Moyogi
"id disagree and say that it does help the new roots that will form as a result of the trench and back fill, especially if i were to add bonsai soil or the rotted mulch."
How? Fertilizer doesn't help new roots form. Hormones released in the tree in response to loss of roots does that. Applying fertilizer does nothing to speed that process.
New feeder roots don't function immediately upon formation and it takes a month or more for them to form on cut roots--which is the reason the there's really no need to fertilize bonsai in the weeks after they've been repotted. Might make a difference if your timing is precise, but otherwise it's really not worth the effort.
How? Fertilizer doesn't help new roots form. Hormones released in the tree in response to loss of roots does that. Applying fertilizer does nothing to speed that process.
New feeder roots don't function immediately upon formation and it takes a month or more for them to form on cut roots--which is the reason the there's really no need to fertilize bonsai in the weeks after they've been repotted. Might make a difference if your timing is precise, but otherwise it's really not worth the effort.