I have a silver birch in a large pot. I'm wondering if I take it out the pot and cut off the tap root and then plant in the garden, would that keep the tree smaller or is that wishful thinking ☺
Last edited: 24 February 2018 16:16:49
The tap root is there for a reason - not only does it feed the tree but also provides stability. And you will find if you do cut it, that other roots will grow to take its place. The only way to keep it smaller is to constrain the roots in a pot or similar or by pruning. Silver birches want naturally to grow to 80 feet!
I'm not sure birches have a real tap root. As far as I know they're shallow rooted and spread. You could try root pruning to keep it contained - bonsai - but, as Hogweed says, they really do want to get tall.
Why do you want to restrict it? If you haven't space to grow it well it may be better to give it away to a good home.
Thank you for your comments. I will keep it in a planter and enjoy it kept smallwe so I can have the best of both worlds. The trunk is starting to turn white which I'm very pleased about