"How do you know when to follow the second piece of advice?"

Basically, with larger trees - over around 10-15m tall at maturity. Anything smaller than that (which includes bristlecone pines in cultivation, and 'Crisppii') isn't going to be much risk.

Resin

To add to what Resin said, if there are two or more stems that grow together with bark included in the area where they adjoin, there is no reliable attachment and trouble can be expected. If a small-growing tree, no big deal.

I remember stuffing three birch whips into a pot to create 'clump birch' for the place i was working back then. Seemed vaguely wrong even then. On the other hand, have seen things like a hemlock and a white cedar growing right together in the woods. Might have got their start on the same rotting stump.

+oM

i agree ....

first.. DONT FIX WHATS NOT BROKEN .... until you can ID a threat to its health or your safety .... ignore it ....

for example ... if you have a hundred year old oak, OVERHANGING the house .... with the noted crotch formation ... its time to act .... if you have a bush that will never be more than a couple meters ... you can see there will never be a reason to act ....

second .... crispii grows slow. ... if you cut out half the tree ..... it will be decades before it fills in .... i would rather spend the next ten years enjoying it as it is, with the SLIGHT risk of future snow damage ... then be irritated by an ugly plant during that time .... if someday it fails... fix it then ....

finally, there are two schools in the conifer world ... those who have to have the perfect sheared Xmas tree shape .... and those who think the weirder the better .... which do you want to belong too??? ... neither is wrong .....

bottom line.. just be the tree ... if its not a risk to you .. the family .. or the house [maybe the neighbors also, if you like them.. lol ].... then let them do their own thing .... no need to be retentive about it ....

good luck .... ken

PS: as an example .... look at this .... should i take off the branch that goes sideways... because the tree is out of some preconceived notion of perfect shape??? .... or do i enjoy it for what it is???

blue wave and bergmans var

{{gwi:790425}}

I've got several Red & White Pine with double stems (never seem to have more than two), and I too have wondered about how these might hold up. The White Pine in the pics is roughly 60'-70' tall and seems to be very healthy. The only thing it would damage if it came apart would be the fence (or an unlucky horse), and I've decided to leave it as is.

The last pic is a rather homely Red Pine with dual leaders forming at about 10' above ground. Would this situation be more hazardous than basal formation of multiple stems? I don't know if its genetic or some other cause, but about 10% of my naturally generated Red Pines have multiple stems.

{{gwi:868523}}

{{gwi:868525}}

{{gwi:868528}}