It does take a while to get on to it. It can be frustrating but it can be fun. I had great success the first year I tried it and had a big failure the second year. It has a fairly steep learning curve, but once you get it down, it is worth it.
That’s EXACTLY what I was thinking!
They don't. Think about how many nuts a mature tree produces every year. Very, Very, few of those nuts every turn into trees. When I was growing chestnuts, most years, about 75% of the nuts I started with made it to a 3 gal RB2 container. Some would not germinate. Some would get some kind of root disease when young. Some just would not be strong growers and get culled.
I'm guessing you haven't gotten the hang of watering yet. I found it took me some time to get it right indoors under controlled conditions. Once they develop an issue with the roots, they often don't recover. The tap root can swell and then the trees go south. I wish I had more tricks to pass on, but my experience is all indoor under light. By the time my trees go outside, they are in 1 gal rb2s and quite tall.
