Hello, I have two bonsai (Chinese juniper and Spruce) both made from garden centre plants. They are both in this really dense soil and plastic pots (Pictures attached). Should I repot or wait? Any help is appreciated.

Thanks.

Sooner or later they will need to be repotted. When the time is right depends on a lot of different factors.

Where are you located? Is it summer or winter where you are?

Are the trees healthy?

Are you aiming for bigger trunk or refining the tree?

When was it last styled?

How long have you had the tree.

I’m located in Scotland where it is currently summer, although not a very hot one and is continuing to rain frequently.

The trees are both healthy and we’re wired around a month ago. I have had the trees for around 2 months.

I never repot in the summer.
Can you wait until the beginning of the Spring? It's safer.

Yeah, that’s no problem. Thanks for your advice. I will repot them in the spring. What type of soil mix do you suggest?

I second clicio and adding:

I never repot a tree until I have had it for at least a full growing season and only if healthy.

I never repot the same year as I style a tree.

If you want to grow trunk thicknes slippotting into a bigger pot can be done now.