Cutting the roots right before top growth appears will just have a dwarfing effect on said growth, will not result in more roots being present.

pruning roots in fall does develop great feeder roots before transplanting. I have done this and seen amazing transformation of the root ball, but figure spring might just stress the plant.

That is why I wanted to know if cotinus is a really tough plant in general. I might just cut it back hard and move it this spring, unless it is fussy, then I’d wait and do the schedule below:

penn state extension says “For most plants, root pruning is recommended in the fall, followed by transplanting in the spring. This allows the plant to grow new feeder roots in the pruned zone over the winter without the burden of supporting new growth. For larger plants, you may want to root prune one year or more before transplanting.”

just move it.. and quit worrying about it ...

i think its going to be hard to kill this beast ... do the best you can.. and dont worry about it ... that said.... if it has a less than optimal season after transplant ... that might mean it only grows a a foot or two.. rather than 3 to 5 ... lol .. so what ....

frankly.. i dont believe in root pruning ... so dont worry about that ...

from the angle of the pic... i dont know why you are moving it.. looks like it perfectly sited to hide that house and car ...

what happened to the huge pine ... it might not be easy digging due the old pine roots.. just do the best you can ... just do it ....and get it done ...

its not some rare expensive plant.. if the job fails.. so what.. get another in fall ..

i hope you note the repeated mantra ... just do it ...

ken

ps: might be hard digging on that hill.. work safe ..

also note.. another reason to maybe leave it there .... is that whatever you plant on that hill ... it will be very hard to water a new transplant for the requisite year or two ....

perhaps according to your soil type ... the water has to soak in and get to the root zone .. not run down the hill

this can be accomplished with drip irrigation .. even if its temporary.. until the plant gets fully established ...

ken

The above assertions about vigorous new root initiation in fall by cold climate adapted woody plants run counter to what is reported elsewhere. With it being asserted that existing roots elongate in fall - fall in this case being when winter stem buds have been set - and new roots are made in spring. With spring in this case being when winter stem buds open. Because this fall and spring rooting behavior is controlled by hormones generated by these winter stem buds.

Presumably this annual schedule is at least the partial basis for warehousing stock dug in November for end of winter/early spring sales as bare-rooted material. And why such stock has dead looking roots until the stem buds come to life, at which time new roots begin to pop out of what often didn't look very promising old roots left from the fall digging process.

Another point about root pruning as a useful preparation for transplanting is that it depends on the roots being cut at a point beyond the reach of the replacement roots when the plant is dug up in order to be moved. If instead the original pruning cuts are repeated at time of digging - as may often happen - then the new roots are cut off and nothing has been accomplished.

Well early fall root prune may still develop some roots. I have certainly seen tons of feeder roots created on both shrubs and trees when I did this: "For larger plants, you may want to root prune one year or more before transplanting."

great explanation of what I have witnessed in action