prune black pine tap roots??

[Joe Dupre']

I received my order of 10-18" black pine seedlings from Musser Forests. I ordered 6 and they sent a extra one about pencil sized. First time dealing with black pine seedlings. Should I prune back the tap roots when I pot them tomorrow? If so, how much.

The seedlings were actually much bigger than advertised, which is OK by me. The longest two were about 24" tall. Very healthy plants with some branches down low on most of them.

 

[nuttiest]

I wouldn't cut them but I like deep tree pots for the first couple years. Those are nice trees!

 

[Shibui]

I think it is a pity these were not root pruned well before this stage. The earlier initial root prune is done the better the tree recovers and the better the eventual nebari.
I would definitely root prune now.
I can't really see where the laterals are coming from in the photo but I generally prune to leave 2-3 strong lateral roots. If the initial root prune is done early enough you can guarantee new roots growing from above the chop so I just chop very young seedling tap roots around 1-2 cm long even if there's no laterals. As the tree gets older that ability to make new roots diminishes so, at this age, I always cut back to lateral roots to be safe. You may be able to reduce further in a year or 2 if they respond well.
If you end up with lateral roots at different levels on the trunk use that by planting the trunk on an angle that puts those roots as close to horizontal as possible. Initial trunk angle seems to give much better trunks later.

 

[Joe Dupre']

To be fair, Musser seems to cater to commercial landscape type activities and not to the bonsai crowd. If these trees need to be in deeper containers, so be it. I'll prune the tap roots sparingly. This group was meant to be a learning experience on how black pines "tick". I didn't want to tackle really nice material until I had a bit of experience under my belt. At about $5.00 apiece delivered, it's a pretty cheap crash course.

 

[Potawatomi13]

Yes. As long as several good side roots remain. Personally would take back at least 50% or more if side roots allow.. And stake up trees for stability. This is most important with reduced root support. Very young trees with great after care have generally great survivability. If you have pumice use 100% at about 1/8-3/16"size. Use well draining substrate for sure. Also choose planting angle now based on root availability near surface. Once survival is obvious fertilize heavily.

 

[Brian Van Fleet]

I would probably cut back to here, and reduce again in a few years. If you plant them in the ground, you’ll want to dig them up every 3-4 years to keep the roots close to the trunk. Pines’ feeder roots get pretty far out from the trunk over time.

 

[Joe Dupre']

I would probably cut back to here, and reduce again in a few years. If you plant them in the ground, you’ll want to dig them up every 3-4 years to keep the roots close to the trunk. Pines’ feeder roots get pretty far out from the trunk over time.
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Kind of surprising. I would have cut about 3" less off. It's great to have all of this information at your fingertips. It's funny. I have a friend who never goes on bonsai forums and hardly ever watches bonsai videos. I tell him he's missing out.

 

[Srt8madness]

Kind of surprising. I would have cut about 3" less off. It's great to have all of this information at your fingertips. It's funny. I have a friend who never goes on bonsai forums and hardly ever watches bonsai videos. I tell him he's missing out.

The two guys that replied to you have infinitely more experience than me, but I would add, when taking that much tap root off, make sure they seedlings are really well secured when you plant/pot them. If you can do that, you'll end up with some nice lateral feeders. A 2' tall tree with only a few roots is a challenge to keep steady.

 

[Srt8madness]

Thanks for dropping the name, just ordered 10 seedlings myself.