This is my seedling sugar belle citrus tree. SB trees from Florida aren’t available in Texas as it is patented so the only way to grow a tree is to grow out a seedling. I got some fruit and saved the seeds. Most citrus are true to seed. I grew a seedling out big enough to get budwood the first year. I then took buds and grafted them to a swingle root stock. Swingle is very vigorous which is what I wanted to make the sugar belle grow ASAP. After 6 or 7 years my seedling is finally flowering. The tree first flowers at the top and the tree has to be pretty large for first flowering. A friend also grew one out for me and his bloomed last year and I tasted the fruit, yup sugar belle! I collected bud wood from his tree last year and topworked a pixie tree to it which is also flowering this year. Here is my seedling tree. https://flic.kr/p/2iHSpAK
This is the size more or less for a seedling citrus to fruit, 8-10 feet! IMHO chances to get a seedling to fruit in a pot are very low. However a friend has 3 gallon sized marumi kumquat seedlings flower. I’ve had citrus seedlings fruit in 2 years but a friend waited 17 years for a cocktail grapefruit! 5-6 years is about average when grown in the ground. I’m currently growing out from seed: giant key lime, daisy SL, and neopolitan. Daisy LS and neopolitan also aren’t available in Texas. Paid $250 last year to get giant key lime and red finger lime bud wood and not a single bud took. Have grown out in the past sunquat and seville orange. Not worth growing out seedlings for any citrus that has available bud wood. BTW here in the Houston area there are many seville sour orange trees in people’s back yard. That is what you get when a freeze kills the graft and the root stock grows out. Sour orange not much used as root stock in my part of Texas.