Black pine from seed

I have never grown black pine from seed. All the info I can find is growing them in pots then transplanting. Has anyone ever just planted the seeds in the ground and let them just grow from there? I plan on making a growing bed and planting the seed in mid April and wanted to just grow them from that bed until I think they are big enough for a pot. If anyone has done this and found it effective please let me know. With the extremes that ideal with every season I was thinking the faster I can develop the root system the better. Thanks in advance.

The problem with just starting them in the ground is that they will probably not develop good root systems for bonsai. This is because they will have a strong tap root.

The best pine root systems appear to come from seedlings where they are converted to a cutting soon after they sprout so they develop a nice radial root system. Jonas Dupuich has a nice article here http://bonsaitonight.com/2011/07/01/how-to-create-seedling-cuttings-japanese-black-pine/ on the process, but there are other articles as well. You then repot at about 2 years of age.

I generally start most seeds (primarily pines, maples, and elms) in a fairly shallow (2.5", 6 cm) flat by spreading the seed and covering. I let them grow for about 2 years in a fairly fine (1 - 3 mm) soil mix. I then knock the soil off them, trim and spread the roots, and repot - often back into a similar flat on about 3" (7.5 cm) centers to give them a little room. I repeat the repotting process about every 2 years to get a decent root system.

The advantage of the cuttings approach is that you start with either a good radial root system that can be allowed to grow for a few years before repotting or a seedling that you toss in the rubish bin. My process gives slower growth, but is a bit less fussy at the start. In either case, it is a good idea to get a good radial root system started before you grow the trees in the ground.