Well, it probably would like more sunlight. But, I can say from experience that gingkos grow painfully slowly. I had one at my previous house which I planted. In fifteen years it grew only about 10 to 12 feet tall and was still thin and gawky looking, limbwise. To tell the truth, it was disappointing and I did not plant one here.

We have several ginkgos on our place. We never fertilize--other than a little compost in the original planting hole 6-7 years ago. We might water (deeply, but not often)in severe drought, but we do mulch a ring around them so we don't risk weed-eating against their trunks. Ours are in full sun and doing well, though the mother tree in Indiana seems lusher in summer. I'd guess more sun would help. Good luck. Maybe there's damage/trouble below ground. ???

try cutting half the branches off leaving two inch stubs (ginkgos do not heal like other trees do, thus the two inch stubs) this will force the tree to grow taller faster. go from bottom up to halfway leaving the top half alone. Also cut the tree down that is blocking the sun if you can. they grow better in sunlight. a japaneses gardner gave me this advice about cutting off lower branches to stimulate upward growth.