Citrange said........."Then they tend to branch low down, and finally it is hard, or impossible, to find a straight piece of stem to fit the scion on to! ..........

It all depends on how you grow the Flying Dragon seedlings. I presently am growing 36 FD trees intended to be used as rootstock. I do not allow any branches for the first 8 inches. Because they are growing year around in a warm greenhouse (minimum winter night temperature 60F) they grow fairly fast. When Citrus Joe and I were at UCR (CCPP) we spend an hour in the rootstock greenhouse. They were growing many varieties, one of which was Flying Dragon. They grow them without any branches, zero branches. The trees were two to three feet tall, and the thickness of a Marks-A-Lot marking pen. The single main stem had many leaves growing directly up and down the trunk, and they were very healthy looking. However, not a single branch was allowed to develop. When T-budding/grafting onto Flying Dragon you generally have to wait approximately a month longer then other rootstocks, because FD takes longer to break dormancy. Even though I grow them with a warm night time temperature, they still tend to some what deciduous, and drop some of the leaves. Lastly, Flying Dragon is certainly a major root stock for trees destined to be grown in containers, or for trees to be grown in northern areas with a marginal citrus climate. - Millet

What verities of citrus is ideal for the flying dragon?

Mandarins (Clementines, Satsumas, Tangerines), Oranges (navels, valencias, pigmented), Calamondins, Kumquats and their hybrids, Sudachis, Yuzu, Australian finger limes are one of the good ones to graft unto FD.

Generally lemons and some grapefruits and pummelos will not do well on FD.

NeyerLemon, welcome to the Citrus Growers Forum, we are glad to have you as a member. Thank you for joining. The only recommendation I would offer when planting Flying Dragon, or any citrus seed variety, for use as a rootstock, would be to use a good draining soil, and be sure that the medium is sterile. I bake the medium that I plant in at 185F for two hours, and check with a thermometer to insure that it is heated through and through. - Millet

Thanks
This forum seems really friendly, I will try to be a part of it.

When baking, does the soil lose any useful content, I mean, do we need to support the medium with any extra chemicals,etc. after baking?

Yes it does loses the highly volatilizable nutrients like ammonium which turns into ammonia. Some will also degrade or therrmally react to form inert compounds, but it wouldn't be very significant. You will also lose the beneficial microbes which helps in the chelation processes as well as potential symbionts and killers of pathogens, and of course eliminate dampin-off fungi which causes the death of most seedlings. But hey, it is a sterile media that you're after and there are some things you lose. Fortunately for the nutrients, you can put them back but not a lot is needed or germination. To prevent or minimize recolonization of the bad microbes, you will have to place thin layer of sand on the top of the potting media where you planted the seeds.

Thanks for the detailed info JoeReal

I take 2 years to get big enough to graft, pencil size or larger, one year in a community pot and 1 year in the ground. In a greenhouse, they can be grown to pencil sized in 1 year.