Thank you! Below is a pic of what we have popping up in the backyard. I did find a seedling out there that looks different from the seedlings in the front yard, shown in the first post. I'm sure I pulled a few of the PI seedlings too, but it would be nice to know that what we have in the front yard is something harmless.

I have news about the ivy. Two things have changed in the two years since I cut all the ivy trunks around the tree. First, I got a new tool, a vibrating multi-tool, that makes it incredibly easy to cut through the vines. I had previously used a little curved hand saw that was difficult to use on the tough trunks. Second, this venue was so focused on finding a missed bit of ivy that it made me doubt my own certainty that I had done a complete job. I went back to the tree, this time with my new tool. I went around the tree, cutting all the trunks evenly at about six feet high, near the top of my reach. To be clear, there are about 7 to 10 trunks the size of a silver dollar or larger, and there are also maybe twice as many that are smaller. To give an idea, at one point, high up in the tree, the ivy began growing downward, like the vines Tarzan used to swing around the jungle. When we bought the house, it was maybe 10 feet off the ground, and swayed widely in the wind. Over the next 30 years, it grew downward to reach the ground with a vine the thickness of a broom handle. The old tool was a curved saw and it was a difficult tool to use in the tight nooks and crannies. The new tool made it easy to make several cuts, as needed, just to completely clear out the mess. In the past two years, the vegetation on the ground has changed a little and so it was a bit easier to see what was going on. The big change, however, was the new tool. In the end, I did find one small bit of ivy, maybe the diameter of a quarter, that was snaking through the middle of two twin trunks. I really had my fingers crossed as I cut that one bit that looked to be the culprit. It worked! I wanted to wait to be sure, but the ivy is now clearly almost dead. There are very few remaining green leaves, a few more remaining brown leaves, and on the ground, it looks more like fall than springtime. What I find amazing is that the small single ivy trunk that I missed was able to supply the entire plant with it's needs for a connection with the ground. I literally took away probably 95% of it's trunk system, leaving only one small connection. I might have thought that the different entwining trunks would each supply one portion of the plant. Instead, that single point of connection to the ground seems to have found a way to share it's connection with all the other disconnected trunks arising toward the sky. Where the ivy trunks were deeply intertwined, I think that they must have somehow grown together, such that they were sharing resources. When all but that single small trunk was severed, that single small trunk was somehow able to provide enough for the entire, huge mass of airborne leaves, and was able to connect with the other trunks which had clearly been severed. These trunks were on all sides of the tree, but sort of interwoven. Still, that means that water from the single remaining trunk somehow connected with other trunks, which then went on to connect with even more trunks until the entire plant was again connected to the ground! That is one tough plant! I do recall this scenario at the time of the original cuts, two years ago. At first, the ivy began to die, a little. Some leaves turned yellow and fell off. I was expecting it to continue all the way, as I had seen many times. Yet, somehow, after a few weeks of losing leaves, the loss of leaves stopped, and then the worst thing happened: new growth was obvious! So the story ends like this: yes, there was a single, small missed piece of trunk. With my new tool, I really cleaned up the trunk of a lot more deadwood, and in the process, was able to cut that final missed piece. The loss of that final connection to the ground now has the entire ivy nearly dead. Having that success with the tree closest to my home, and easiest to explore, I geared up to re-visit the Douglas Fir. It is on a steep slope, and difficult to approach. Again, I think I may have found one, tiny missed trunk, and I severed it. I also cleaned up a lot so that the ivy trunks were easier to visualize. It has not been as long since I made the new cuts, but it does seem that the leaves are in the very beginning stages of turning brown and falling off. Fingers crossed! Time will tell, but I think I have finally finished a job I began two years ago, and I'm ultimately relieved.

norways also tend to have surface roots.. down thru the decades.. and with their very dense canopies ... might cause nothing to be grown under them ... including potential inability to grow grass .. keep in mind... i am talking 20 to 40 years from now ... also keep in mind.. you can always plan on removal ... somewhere down the line ... my usual deadline was the season i could take it down for free ... as my drop dead decision season ... my favorite trick.. is to google up the latin name ... and then read up. AND .. flip to google images ... to SEE ... the future ... your reliance on common names ... is part of what is holding you back.. to get good info ... ken PS ALL trees can split on the sun side in winter.. its more a function of proper planting .. and proper after care ... and maybe some winter protection for the first few years.. rather than a trait of a given tree ... in other words.. its a stress reaction ... PPS: it would be nice.. to know more about your whole property and goals and stuff ... you have done quite a few posts here .. and frankly.. i hope you have some acreage .... maybe you addressed this in some other post.. or maybe you could start a new post on the whole process ... first to this page to find the latin ... i see it in 1st link ... https://www.google.com/search?q=Deborah+Maple+Tree&ie=utf-8&oe=utf-8 then using such .. this link https://www.google.com/search?q=Acer+platanoides+%27Deborah%27&ie=utf-8&oe=utf-8 then to this link https://www.google.com/search?q=Acer+platanoides+%27Deborah%27&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjoiPrgsb7MAhVHmoMKHb-ZB_kQ_AUIBygB&biw=935&bih=745&dpr=0.9

Gardengal, I had for some reason assumed the current poster/bumper was going to cut and then apply. Not just try to use the herbicide alone. Agree with you it has to be former. I would disagree with you about adding supplemental surfactant, even for application to stems, and "dish soap" (actually detergent of course) is what most people have on hand. The stems of Ivy, like the leaves, are very "suberized" and hydrophobic, and any water-based herbicide that is applied (which I'm just going to wildly assume all consumer products are, although I've barely used them since I owned my current garden!) will run right off them without it. It's been SO long since I treated vines - and for me it's mostly been poison ivy which has the hairs. Triclopyr ester of course, has no trouble sticking without a surfactant. Commercial "3 way" amine, although water based, would stick because it's so concentrated. But I was guessing a more dilute solution of whatever, sold at big boxes for homeowner user, would need some help. I do remember, for example, that the year I moved here, name brand "Round Up" shed right off the leaves of things like Euphorbia peplus. They gave it the bare minimum of surfactants and that wasn't enough for some weeds. That was almost 20 years ago. Maybe today's formulations are better. *