If it were me, I'd prune the sucker and give the central leader a chance. What you describe of the central leader being all contorted is fairly common with young ginkgos.
Suckers on the other hand, not so much. Aside from the twisted shape, does it look healthy? Lots of leaves?

There is some reason for all those suckers. Take some good pictures...one of the entire tree, one showing the trunk's structural problem, and one at the base where the suckers originate. Maybe that will tell us something. Also, take a good look at the trunk and see if there are signs of physical damage.

Right now, I wouldn't remove the trunk or suckers until I tried to determine what is happening. Based solely on the info so far, I think I'd be tempted to remove the original trunk and keep the strongest sucker, but we need more info for a more informed decision.

Sounds like sucking from below the graft, to me. Named cultivars are grafted onto seedling root stocks. By allowing the root stock to take over the grafted Philadelphia, you'll be at the mercy of whatever kind of ginkgo the root stock is. And it might very well be female, besides having none of the characteristics that made you purchase the variety you did.

As has been said, young ginkgo grafts are often sorry looking specimens, taking several years before they grow out of that awkward stage and evolve into handsome youth.

Yeah, but Hald said they weren't believed to be grafted.

Wonder if the OP is not confused and it's 'Princeton Sentry'. I can find no reference to a cultivar "Philadelphia". Not that I'm an expert on ginkgo cultivars. In any event, I've seen many perefectly healthy thick growing grafted and ungrafted gingkos sending up suckers. Not surprising at all. I would remove the suckers, but that's me.

Arktrees

can you name a seedling variety???

perhaps the graft is planted below ground level ... and the reason the sucker is coming from underground.. is because it's planted too deep ...

if it were me.. i would do some archeological digging around the trunk.. and see what is going on there.. then snap some pix... and then post them here for us to give some informed opinions .... otherwise all we can do is speculate ....

and i for one.. would not pay a premium for a named cultivar and then cut it off ...

ken

Ginkgo cultivars can be grown from cuttings. Although grafting is more common, it's not the only option.

The cultivar would only be lost (by cutting off the leader) if the tree was grafted.

Yes, it's been almost exactly a year since my first post. During that time I've done little to the gingko trees besides water. I still would like advice. I posted photos to Photobucket and put them in a public folder. I've never done that before so I hope I did it right...

I bought 5 "Philadelphia" variety gingko trees several years ago. At the time I was told they were grown from cuttings taken from the 1st gingko tree planted in the U.S. which is in Fairmont Park in Philadelphia. I bought the trees at a fundraiser, so I suspect they may actually be the Fairmont variety. Originally they were in 2 gallon pots. As they grew I moved them into 15 gallon, and eventually planted them in the ground last year. A few months before that the wind blew one of them over and my gardener cut the main leader of that tree, I think because he didn't realize what he was doing and it had fallen in his way. I stressed about planting it but planted it anyway.

In the photos you'll see of my front yard the 3 gingkos are planted at odd angles, not straight up and down. This is because 2 of my neighbors helped me plant them and one of them, who is a master gardener and on the board of a local botanical society, said that it would look more artistic if they were planted leaning. I still have questions about whether this was a good idea. Since being planted they get watered weekly by flooding the area they are planted in.The area where they were planted was a blank slate - all the lawn and everything else was removed. I hired an auger truck and had several holes drilled for drainage. The holes were 18" across and average about 15 feet deep. We drilled till we hit sand for drainage. These holes were filled with large gravel. I then rented a tractor with an huge auger and worked in many cubic yards of organic compost into the planting mound and planting area; I'd say I worked the compost down to an average of about 7ft. The soil throughout my entire yard is hard pan, and it is as hard as concrete before it is amended (or removed). I routinely use an electric jackhammer (demolition hammer) to dig when I am planting things.

The gingko trees in my backyard were planted in the ground 4 years ago. I had holes drilled, 18" across, average about 12 ft deep. I didn't do any major soil amending or enlarging on the holes. I had a hope this might stunt the trees and keep them small, and it was also an experiment to see if anything would grow this way. They are are watered on a drip system with shrub emitters and get about 6 minutes a day.

Most plants in my neighborhood struggle with the hard pan, and most, including trees, have roots that penetrate only about the first foot or so of soil. The soil is nearly 100% clay, literally the type you'd make pottery with. But it does seem to be very nutritious when it is amended.So my questions:

Should I leave the tree with the cut main leader in my front yard, or dig it up and replace it?

In the photos of the trees in the back yard, the tree on the right on top of the mound has always been crooked and ugly, but has now sprouted from the root. Should I cut down the original ugly main trunk and let the shoots take over?

On the tree to the left in the back yard, should I retain the original trunk and cut down the others? Retain them all because I think it looks nice, or?

Besides the soil I have, I also live in a very arid climate. 20% humidity is considered muggy here. It usually averages more between 10 to 15%. Also, especially in the front yard, heat is a major factor. Last year we had over 30 days above 100 degrees, with many days over 110. At the back of the photo of the front yard you can see a big rock. I used an infrared thermometer this summer and measured the rock temperature at more than 145 degrees in direct sun. The trees get direct sun virtually all day.

Thanks for all the posts and advice. Here's my attempt at posting photos:
Here is the link to my album on photobucket:
http://s1131.photobucket.com/albums/m547/halddd/

I had the instructions for posting photos open in another tab. But the instructions aren't working for me. I hope the link above will work. I put links to each photo below.

Photos:
1.
{{gwi:464776}}
2.
{{gwi:464777}}
3.
{{gwi:464778}}
4.
{{gwi:464780}}

6.
{{gwi:464782}}
7.
{{gwi:464784}}
8.
{{gwi:464787}}

I am prone to keeping the original stem. But as Ken said last year we still need to know why they are suckering. Like Ken, I suspect depth. Can you see the root collars?

The broken leader is another problem. If it were me I would keep the tree and train one of the branches to assume the lead. You have several side branches competing for the leader role. Eventually one will out grow the others but the losers will be too large by then. I would choose one and prop it up, and reduce the rest.

I question the advice of a "master gardener" that helped you plant those three in the front. Ginkos grow pretty slowly when young, but eventually they will take off and be pretty big trees to be this close together.
Ginkos are really tough trees, so even if you do nothing they are likely to out live all of us.

Not only that, but big trees growing close together & leaning to begin with may lean out away from each other aiming for sun exposure, putting some real strain on the trunks when you have high winds. And I see they're near a house.

Richard.