It sounds as if the lilac really needs to go. Full size lilacs are big shrubs and wacking it back every year will result in a very odd looking specimen pretty quickly.

Digging around a gas main would be an extremely dangerous undertaking, so cutting the lilac back to the ground and treating the stump with herbicide is the best way to go.

Japanese maples are very easy to move, but if it's also near the gas line, do not dig.

i dont know.. its SAD time on GW ... i have been getting in trouble for 'straight talk' ... lol ....

a pic would really help ...

the lilac .. with a hand trowel.. and presuming you want to save a piece.. dig out a sucker with some root ... and move it to a good location ... most of my lilac are 8 feet tall and at least that wide ... if you dont have a space for something that size.. just kill the thing ...

as to the gas line .. congrats for knowing its there.. lilac is rather shallow rooted.. and short of using a sawzall.. or really jumping on a shovel.. you arent going to break thru a gas line ..

have it marked in advance.. tell the guy why.. and ask his advice ... they dont like to admit it.. but their gizmos can ESTIMATE depth ... at least giving you an idea if it 3 inches.. or three feet down ... he should also be able to tell you if its a galvanized pipe or not ... knowledge is power ...

whatever they tell you.. just start an archeology excavation.. and get the job done ... it obviously isnt going to be a grinding job ...

and because its right there at the front door.. i would make the effort to dig it out.. rather than kill the stump. and leave it there for 5 years to rot away ...

like the rest of us.. you want the fast easy solution.. there isnt one.. just an afternoon of gentle digging and slaughter.. lol ..

as to the JMap ... they take well to artistic pruning.. trees are made to cut on .. they can deal with it.. with just a few rules ... on PROPER CUTS

this tree should NOT overhang the walkway ...

again.. snap a pic before it leafs out.. and we can give you guidance on how to prune it ... i do it thru my photoeditor ... and give you a picture of what you should do.. and then everyone argues about it.. lol ...

so.. three jobs..

figure out how to post pix

dig out the monster

prune the JM ...

there you go .. 'straight' as i can make it ... dont be lazy.. or delay.. waiting for some miracle cure.. it aint gunna happen ... its one of murphy's rules of gardening ...

ken

This is sad to hear about, but I think the lilac needs to go too. Syringa will gladly become a clump or hedge if one starts hacking it, heavily pruning it. But if one plants a single-trunk entity, it can turn into a lovely tree with just a few weak suckers to be pruned yearly. Something to consider with the pieces you remove.

The tree pictured below is too close to the house, don't do that, but is still a lovely example of a lilac tree instead of a shrub.

Hmmm. This is the picture of truth!!
Your lilac is lovely- I love lilacs-- but I do not need that right there under my eves. Mine is technically planted against the foundation. (5 inches away)

There's only about 12 feet between my house and my neighbors (old 1929 houses) - and besides all my stuff growing over here in my yard, my neighbors have let a mountain ash volunteer under their eaves. It's 20+ feet tall now meets my roof. They also let 3 WALNUTS volunteer under their eaves as well and those were 4.5 feet tall last year. (The squirrels plant walnuts all over the place.) It's tight quarters in my side yard with all these shrubs and trees )probably all within 15 linear feet)

Ken I understand your sense of humor-- read some older posts.
I wish I could dig it up with a hand shovel, but I am terrified of hitting the gas main (again) and so I think I have to use round up. the lilac is probably rooted under my new paver walkway anyway and I won't be capable of getting all that root mass out to prevent future suckers without disturbing the walkway.
I don't want to use roundup, but I think it's come to that.

Thanks all for helping me know what to do.

Unfortunately Syringa won't grow down here, that pic is from OH years ago. Still miss that tree although we always wondered "what were they thinking" about the placement, right against the house like yours. Glad you like it too! ...but just in case it's pretty enough to make you consider leaving yours, know that it was beating the roof edge up pretty bad, and the most likely explanation for the cracks in the basement walls inside that same corner.

If you are going to use RU, I would trim everything as low as possible for now (on a day when it's not too unpleasant to do so, not saying you gotta run out there tonight!) You probably know one should wait until it is warm enough for the RU to work well, and a day with great sunshine. At that point, if the manual insults haven't been deadly, the RU should work well on any weakened remaining foliage, with the smallest possible amount (just enough to coat the leaves.)

RU may not be necessary if you're the micro-manage type and have the time and inclination to "kill it" every time you see new leaves. You should know by the time it's warm enough for RU to work well if that's a battle you can win with your available time and desire, if it's something you feel like trying.

Regarding the walnut trees, you may want to investigate juglone sensitivity, so you can avoid wasting time/money planting anything on "the list" near those.

you misunderstand...

you start excavating.. with a regular shovel.. out about 2 feet from the trunk.. just working your shovel around and moving soil around ..... when you ID a large root ... and you expose the top and sides.. and then you use the hand shovel to get under and around.. so you can work a saw in there .. and cut the major root ..

by excavating.. you can 'see' where the saw is working.. and you wont cut a pipe ...

i would bet there are only 3 or 4 major roots ...

ken

I should take a picture-- the plant only has 15 inches of width to grow in -- then there's my fancy pavers. they only go about 6 inches down, and so lilac roots go under and across. Digging under my pavers to chase that root would undermine, literally, my pretty pavers and they'd probably get all wonky and uneven. Gotta glyphosate em

in your ventures around GW .... have you found my discourse on the very expensive applicator and how to kill things???

i dont have time this morning ...

ken

I haven't - I assumed I'd paint it on in a strong concentration? but, I'll look for your applicator discourses. ;-)

Here's a link to a thread with Ken's herbicide applicator link.

Here is a link that might be useful: Ken's applicator

thx nh..

i have time.. i can do better ...

link to very expensive applicator ..

remove product.. wash.. insert 100% roundup.. [labeled as 41%] ...

cut tree/shrub to ground level ...

apply a drip line around the edge of the stump ...

put RU back in labeled container... wash out applicator ...

check once a month.. if any new shoots come up.. snip them off.. and put one drop of RU on the CUT ... repeat until surely dead ...

whole project might take 1 tablespoon of RU ...

it becomes inert on soil..

ken

Here is a link that might be useful: its the applicator not the brand name