I'm in Aiken, SC and have had a norfolk island pine for a few years. I repotted it at the beginning of summer this year and decided to keep it outside in the warmer weather. Apparently, it liked the spot I chose because its roots have outgrown the pot and it is stuck to the ground. I don't want to leave it outside when winter comes, in case it gets too cold for it. But I've also read that these pines' root systems are very fragile and I don't want to rip it up from the ground and possibly kill it. What's your advice?
Potted Norfolk Island Pine Rooted to Ground
Certified GKH Gardening Expert
The fact that roots have grown from the pot into the ground is the prime indicator that your tree is root bound. So the solution here is to either repot your Norfolk pine in a larger container, or to plant it in the ground. Either way, you're going to have to cut the root that is leading from the pot to the ground.
Since planting outdoors is not really an option where you are (as the tree won't do well in winter), repotting looks like your only alternative. While repotting, it would be a good idea to root prune, which will slow its growth some but is better for the tree's overall health in the confines of a container. This article will help with root pruning: https://www.gardeningknowhow.com/houseplants/hpgen/prune-roots.htm