I'm new to bonsai, and I found a spruce seedling in my yard that looks promising. I dug it out and got about 2/3-3/4 of its roots. It's already pretty big (about 9 in. tall) and has a fair about of branches growing from it. I potted it in a mix of bonsai soil (lava rock, pin bark, calcined clay, and pumic) and black dirt. I'm thinking I would water it once every 2-3 days. It gets about 3 hours of direct sunlight and 3-4 hours of indirect sunlight. I'm looking for advice on how to care from it from here. I've noticed a couple days later that a couple branches that were already slightly yellow have gotten more yellow. It's now been about 3 days since I potted it. When should I start training it? Is it strong enough to train this winter already or should I wait a year or 2? Is there away I can help it recover from being potted? Being autumn in Minnesota, should I still apply fertilizer and if so what kind? Attached is the sapling as of today. Thanks ahead of time.
