Hello all! I'm new here and am curious if anyone knows about pot size for a seedling/young tree. The reason I'm asking is because if I keep them in smaller pots under 1 gallon outside over the winter I am worried about roots getting damaged in the cold as it gets cold in washington state...also I'm wondering if there is a way menipulates trunk size to grow bigger faster in a young tree...thanks for your time!

You don't mention species, so the answer is general.

Trees grow faster the bigger pot they are in. That is valid for the whole tree, trunk, roots, branches and leafs.

Keeping locally hardy trees outdoors in winter normally don't pose any problems. Try to keep them away from cold dry winds and excessive rain. A good open substrate will be beneficial as well.

Tropfrog is right. Bigger pot will speed up tree growth. Well textured soil will prevent roots fro being overwatered. Best winter storage is on the ground, in protected from wind and rabbits area. Snow is good, but too much snow can break branches. I’m in the Pacific N/W area as well.

Thanks for answering and yes I just needed general advice as I have a few seedling around the house to dig out of ground and bonsai eventually....have black walnut trees...English walnut trees and a couple Japanese laceleaf maples that all came up outside...basically if I have them potted on porch where snow won't get to them I'm hoping they will be ok...i dont have a safe area where i can keep them in ground as i have dogs and deer roam freely out here...they are all just seedling that came up around my house and wanted to see what I can do with them in time. Thank you

Just don’t forget to water them from time to time while stored under porch roof for the winter…

I have small temporary pots and 1 gallon pots....not sure what ones to use as black walnut is a fast grower and would like to keep them on the smaller side so they don't get so leggy....these tress pop up all over my grandma's property cuz of squirrels so figured I'd give them a try.

These are the small pots I have they are 3.5 inch pots wondering if that's too small to put the walnut trees in... they are a bit bigger than the maple in this picture.

Snow is good for trees in winter. It gives water and isolation from the cold and wind. If you keep your trees where snow don't get to them you may want to consider showling some snow on them.

10 cm pots is not too small. But bigger is better at this stage.

Ok that makes sense, thank you. I may go get some pots that are between the small size and the 1 gallon. I want them to get bigger but not to where they are getting tall too fast. Hopefully that will work out...also not to sure how well black walnut is for bonsai but maybe it will be good practice as they are all over the property.