Weird growth on landscape spruce

[clevetromba]

I drive by this tree in my neighborhood every day, and only recently noticed the strange growth on the top of it. Would this be considered a witches broom? I know the pic isn't great, but the growth is so rounded and compact and full of cones compared to the rest of the more typical spruce growth habit.

 

[Bavarian Raven]

Basically yes. It's a genetic mutation. I've seen it occurred in a few trees in the wild.

 

[TN_Jim]

Wow, thats crazy. Just read it can be caused too by a bacterial paracites (Phytoplasmas). Wacky stuff, that's a new one.

 

[GGB]

I drive past an eastern white pine sometime and the top of it is similar to your spruce. It's like a perfect sphere of foliage

 

[Zaratrusta]

I never seen/heard about something like this. Wow.....

 

[Giga]

yeah i bet at some point the apex was affected with something and then affected all the top growth from there on.

 

[sdavis]

Yes, this is a good example of a witch's broom.
It can be caused by an infection (sometimes a virus) or by a genetic mutation.
Mistletoe can also lead to a similar phenomenon.
Many of the "dwarf" varieties of conifers found in nurseries started out as a broom and were collected and grafted onto a healthy under-stock.
Of course the genetic mutations are the desirable ones. The infectious ones don't propagate well.
If you start looking, brooms are not that uncommon in western conifers.
See the American Conifer Society's website for more examples.

 

[miker]

Yes, it looks like a giant apical witch's broom!

Most of the interesting conifer cultivars/variants come from chance witch's broom discoveries in the wild.

 

[Velodog2]

This happens in reverse too, particularly on the ubiquitous dwarf Alberta spruce, where the mutation that presumably made the original witches broom reverts to normal growth on a tree making what seems a relatively huge, but is actually a normal sized branch. I have a Japanese maple 'Butterfly' in my yard this has happened with, although I'm not sure if that cultivar originated as a somatic mutation like this. I've allowed the reversion to grow since the form is similar to the original it's just the leaves that have lost their variegation, and have a half-n-half tree.

 

[M. Frary]

I can drive down the road and find these in lots of places here.
I have 2 Scots pines that try to grow them. I cut them off.

 

[Aiki_Joker]

I can drive down the road and find these in lots of places here.
I have 2 Scots pines that try to grow them. I cut them off.

Interesting Mike. Have you seen these occurring lower down on any SP trees (natural or bonsai)? I think I may have seen one recently, it was not apical, but in the crown nonetheless.

 

[M. Frary]

Interesting Mike. Have you seen these occurring lower down on any SP trees (natural or bonsai)? I think I may have seen one recently, it was not apical, but in the crown nonetheless.

Yes. There's a red pine with one on a limb about 25 miles from here.