Oops - you would have been way better off (sorry!) to have left it in the ground where it would a) grow much faster, b) have the benefit of all outdoor things trees need, like natural light and humidity, gradually changing temperatures, nutrients, rain, etc.etc. and c) experience the cold dormancy it needs to survive winters. Plus, unfortunately, it really doesn't make a good bonsai - growth habits are counterproductive. For the future, potting soil makes a lousy mix for potted anything (including house plants!) as it's full of water hogging peat that interferes with good drainage and 02 use by plants when it (eventually) compacts. Bonsai can't be treated like house plants in any case on many levels, and there is a lot to learn about a lot before you either dig up trees randomly at the wrong times of year (such as now), or spend money on potted things in stores without really knowing how to keep them alive at home (and it doesn't take long before they succumb to bad management). Of course you're new, we all were and have killed many things along the way - you can't know what you don't know, including even what to ask about, so start reading basics like bonsai4me.com, more expert stuff on tropicals from bonsaihunk.us/cultural.html and more of the same on conifers and other trees that need to live outside 24/7/365 (evergreengardenworks.com).

I've observed Liriodendron for decades, it's probably my favorite tree. I'd ask the same questions that Tom has, and add this: the tree looks to be under great stress, it has been pruned to remove dead wood or maybe to 'balance' the loss of roots with the top, there are more dead branches in the top of the crown, and the foliage looks undersized. I've seen forest trees exhibit these same symptoms when the area they are growing in is heavily logged or severe weather removes many cohorts. A WAG (and I hope I'm wrong), the tree will continue to decline and become stag headed. There will be many epicormic shoots from the main limbs and trunk. It will never again regain it's former glory. It will probably live on for years, maybe decades, unless removed. Unless MASSIVE amounts of the root system were removed and the tree is structurally unstable, it won't fall. Large upper crown limbs that die may, however. Old poplars (and many other old trees) do not like to be messed with.

The tree and the house have lived together for a while. you say nothing that causes alarm in my mind, but then again...I haven't been there, and without eyes on, this is incredibly difficult. I'd keep some different folks coming out. maybe you can do it under the guise of an estimate, maybe you'll have to pay up a time or two for on site inspections. So you ask someone to come out and look at a tree. keep the language as open as possible, because as soon as you say, what about taking it down, you have self-selected the direction of the conversation. What you're looking for is someone you will answer your questions and you feel comfortable with. everyone comes into a conversation with an agenda...everyone. but if you're talking to a guy about a tree, knowing he makes money by taking it down, and if he says he really doesn't think it's necessary, he's advising he doesn't get paid. if he say yes it should be trimmed or removed, what's his reason? do other people agree with the reasoning? There's always certifications, more of those than I care to mention, insurance, various methods of checking out contractors. you're starting something a lot of people don't really know well, which is evaluating tree health. there's a lot of people who see a tree close to a house and the only thought they have is it has to come down. I assume the house is new to you? sorry if I missed that above. unless you see something that just scares the living bejessus out of you, i'd wait to see how things look once they leaf out. if nothing else, it'll give you a sense of how specific trees and the house relate to each other, and to the yard. P.S. zero-turn mower. you still need the lawn tractor for cleaning and working, but you'll love the zero-turn for mowing.

This. Is. Not. Dicamba. Damage. Do we need to use caps? Dicamba damage generally causes upward puckering, not downward, with distinct shortening of the midrib, often with discoloration. I won't rule out possible pesticide damage...i use the word pesticide as opposed to chemical because many plant reactions to insect feeding are chemical reactions...but no, not dicamba, 2,4-d or glyphosate. There are several things that could cause such damage in addition to pesticides. The real question is what to do about it. Which is really a question of whether not this presents again on new growth. If the tree grows out of it next year, no problem. If problem persists on new growth, if entire tree is affected, there's not many simple answers. About the best you could do is some fertilizer and ensure adequate moisture. If limited to a branch or two, possibly pruning, if distortion affects branch growth. If limited to foliar development, i'd say nothing needed. I lean towards insect on this one, I really do. I won't rule out pesticide, but in the absence of on site I inspection, twist my arm, I lean towards biotic cause. This is a case where the inclinations of the internet are a limitation. Is this a one time, one place occurrence? Then discerning cause is nearly a lost cause. Is this something seen often locally? Then local personnel are going to know the answer far more readily. Locally, i'm the guy people go to for these answers...and I don't see enough in the pictures or description to do anything more than guess.