they are conifers.. as well as trees...

first.. transplant shock ...

second.. what media did you use in the pots .. as most trees like a very dry media... with a high peat media.. you are more apt to rot the roots off... than underwater .....

third.. why not mother earth ...

4th ... natural annual needle shed .... increased by transplant ...

and finally.. not great stock to start with ...

its impossible to really give you any kind of guidance.. without a picture ...

good luck

ken

Black Pine could one of at least 3 different pines. Do you know which you have? In addition to what Ken already mentioned, where in CA are you and are you using dark containers that are cooking the roots?

tj

Hello - Thanks both.

I am living in SF Bay Area. I think one possibility is overwatering as Ken said. I moved them out to the sunny area to dry the soil.I hope it will thrive. I used soil with a lot of peats (one for pot), it is very well drained. Last week, we had a rain plus, it is in the area close my lawn (subjected to sprinkler). I put them in larger pot (with black color), not sure if this could still burn the root.