you can move anything you want ... thats not really an issue ... see link ...

and frankly.. you will have to try real hard .. to kill a lilac ... lol ... so just time it out.. and just do it ... mid september sounds good to me ...

its a deciduous shrub.. im usually not much concerned about ugly leaves in late august ... in fact.. mine had drooping leaves today.. due to 4 weeks of drought and heat ... but it rained today.. so they will be fine ... i also presume.. you dont see any bugs on the back sides of the leaves???

at the 2nd link below.. is how i try to find pix of older plants ...

since most lilac sucker... i never really contemplated using them for shade.. for growing things planted under them ...

in summation.. move it if you want.. but im not sure about your shade plans ...

ken

planting

https://sites.google.com/site/tnarboretum/Home/planting-a-tree-or-shrub

pix

https://duckduckgo.com/?q=Donald+Wyman+lilac&t=ffcm&iax=1&ia=images

Show affected leaves to somebody at a Wisconsin Cooperative Extension office or an independent garden center for comment. Move when leaves are not present. In USDA 5 you might want to do this at end of winter instead of beginning.

Thank you. I am concerned about the leaves because it hasn't looked that way in the past.

I do most of my moving and planting in early fall since it's more successful for me. The soil is warm and the air is cooling and days are shorter, so there is better root growth and less stress than for spring-planted shrubs when the soil is just above freezing but the air can be hot. Just keep an eye on moisture until freeze, mulch well when you plant, and if your part of WI is as windy as my experience in WI, perhaps stake it for the first winter.

I agree with Embo's suggestion to take leaves and photos to cooperative extension since we have had well over an inch of rain weekly (2 1/2" last week) this summer and mine doesn't look like that. My soil is well-drained, however, unlike many of the WI soils with which I am familiar, so yours may just be a product of waterlogged soil. Some plants do yellow in wet soil or if there's too much rain.

I will look for a photo of my DW lilac which at 15 years old is well over 10' tall.

Edited to add:

This photo is from 2013 when it was perhaps 12' or 13' tall. It's only gotten larger since then. The white flowers are from the clematis Guernsey Cream which grows up through the lilac for early bloom, and the lilac blooms well after the common lilacs nearby and with less scent to my nose. There is a great view of the top of the shrub from the window and doorway behind it, and the last two years have had birds nesting in the upper branches.

NHBabs - thank you! Wow yours is huge! It would not be suitable for where I would like to transplant it. I think I will leave it or possible trade it. I had a professional landscape design done for my entire yard but several of the plants have grown to a massive size and I've had to move them or remove them. Another is a bottlebrush buckeye. It's quickly swallowing up everything planted around it. Frustrating when I consider the amount invested in the design and that is the first bed I had professionals create and plant. I started with nothing at this house.

Anyway, I plan to plant clematis to grow through lilac. They help to keep it pretty. Yours looks narrow at the base which is good for my sight. Did you shape it that way or is that natural growth?

Thank you for advice on leaves. I'll have to take them in.

DW lilac (Syringa x prestoniae) is relatively narrow at the base, not suckering like common lilacs (Syringa vulgaris) IME, though in the last few years DH has whacked it back some to keep it from blocking the door and window or overshadowing too many of the perennials now at its feet. I am not sure how much if any pruning he had done when this photo was taken. I haven't tried growing clematis on common lilacs since I think they would be overtaken/outcompeted by the lilac suckers.

Often folks want rapid results in their gardens, and it is common for folks to not live in a house longer than 5-10 years, so I think that many garden designs, even by some pros, are geared for the shorter term rather than long term. A house down the road from me that was built perhaps 15 years ago and given a professionally installed garden, has already ripped out about half the plants due to the plants overgrowing their space.

I've seen a bottle brush buckeye in upstate New York that was easily 15-20 feet across.

The information I received about my lilac leaves...in a word...malnourished. Because I Garden organically I was told I need to hit it with a chemical fertilizer. When I refused to do that I was told to water with fish emulsion and dig organic slow release fertilizer and bonemeal into the soil. So that's that. I'm moving it next week and will hopefully see it recover in the spring.