So since you've grown the plant from seed, don't worry about graft line and rootstock. People only care about these when they attach a plant (in your case orange) onto another plant. The top would be the orange and the bottom would be the different plant. And sometimes the bottom plant makes branches called suckers and you would want to cut those off because they take energy away from the orange part of the tree.

My pot has lots of drainage holes in it.

Most people us a soil mix such as gritty mix or 5-1-1. If your tree stays put use the gritty mix. I feed my tree with an overall ratio of 5-1-3 or close by mixing fertilizers I have on hand. I water when ever the tree is some what on the dry side With a half strength formula about every week and at full strength if its every 2 weeks. No pruning necessary at this time. Just let it grow and keep any shoots that start close to the soil line. I would stay away from a metal bucket. and use a light color plastic container.

6b Steve

I agree with poncircusguy, but to be more blunt, make sure your new pot has drainage holes! If not, you may end up with too much water which will rot your roots. Use a pan to catch any excess water.

Thank you all for your help! I'd already cut the shoots close to the soil line because I thought they would end up under soil anyway because right now the roots are surfacing - we're repotting in a much larger wooden box, lined with plastic sheeting. I was mostly worried about the forked 'trunk' and whether it should be like this, but it sounds okay from what you've all said. He just seems ver y sparse and gangly. I'll make sure we have decent drainage. We have just a potting mix, but I've just read that this is a major no-no for citrus or if you need gritty mix. We were going to put a base of gravel and sand then soil, but I'll go see if they have a pre-made gritty mix here so it's got what it needs! Luckily, with the exception of big storms, the tree isn't in direct water from rain, although we are in a humid climate so it can take awhile to dry out when not in direct sunlight. Again, thanks all!