Hello everyone. I am new to bonsai, but have gotten very interested and invested. I now have about 10 plants, and many more cuttings starting to root. So far, I have had great success. I have trimmed most of them and am starting to see them get denser. My question centers around root trimming, repotting, and soil.

- many of the plants I got have come in sort of typical potting soils. they seem dense and hold water for many days. do ALL bonsais prefer acadama, or pumice, etc? at what stage? they came growing in these soils, how does trimming them effect what soil they should have? here are some examples

juniper (2-3 inch high cuttings), serissa, coprosma, grewia occidentalis, and more.

i live in colorado. It gets very hot in the summer and also very dry. 90 degrees for many weeks in june. I would imagine some greater water retention would be good.

So, i trimmed them. when should I repot them? when should I trim the roots? to what degree? if I want them to gain mass in the trunk, should I trim the roots less? should I leave them in their (dense) soil if i want them to grow quickly?

let me know if I can clarify any of these questions, and thank you for your help this hobby rules!

-charlie

Hello and welcome

A few pics of your plants could be a great start ; )

Jodo wrote:

juniper (2-3 inch high cuttings), serissa, coprosma, grewia occidentalis, and more.

So, i trimmed them.

You trimmed 2-3 inch juniper cuttings

when should I repot them?

When it is needed and at the right time.

when should I trim the roots?

When you repot them, if it is needed.

to what degree?

Depends on the type of tree, health, stage of development, your goal etc.

if I want them to gain mass in the trunk, should I trim the roots less?

You don't trim.

do ALL bonsais prefer acadama, or pumice, etc?

No.

let me know if I can clarify any of these questions, and thank you for your help this hobby rules!

Your questions are too generic. Look up the guidelines per species, to learn when to repot, when to trim, when to prune roots, what soil they require etcetera.
Also: slow down. There is really no need to start cutting / trimming / repotting all your young plants. Learn to grow them first.