"...Several years ago..." and this is all the bigger it is? Has to be too much shade. Not a good location. This fall, after it loses its leaves, dig it up and transplant it to a sunny position. You have all summer to find it. As soon as it gets enough light, it will grow standing on its own.

Yardvaark,

Thank you but I cannot transplant it. I planted other young lilacs in the few areas where there is constant sunlight and they did not survive. I therefore do not want to take the chance.

I'm in a condo building in a MA city that is one of the most densely populated areas in New England. There are city trees in our front yard that create shades. And our 12-unit, 3-storey building creates a permanent shade in most of our back and side yards.

Do lilacs survive well only in areas with direct sunlight?

Do lilacs survive well only in areas with direct sunlight?

Yes,pretty much. This one is obviously reaching for the sun.

Something else to check is the soil pH.

Here's another photo I took today (a few minutes ago) to show how it looks when the sun is shinning directly on the lilac.

So if it needs minimum 4-6 hours of direct sun but it gets 20 minutes .... how does a picture of its brief time in the sun make a difference?