Those should be gorgeous when they bloom.Your yard is lovely and i LOVE those white iris's.What is that little yellow flower that looks like it's setting right on the leaves???
TFS
Kathi

Thanks Kathi- The little yellow flower is a Lysimachia ciliata. I thought it was a big weed, but someone on another thread was able to identify it for me.
-Sprout (Linda)

how are these an eyesore, again>...?

Sprout:

It looks like the previous owner already trimmed some down. Some are short, some are high. Given a few years, they should all reach the same size (about 8' or so). It looks like there might be a couple holes in the hedge too, it's hard to tell though. If there are holes in the hedge, go ahead and put a new one in.

For the shorter ones, just let them continue growing back to what they used to be. It doesn't look like anything is wrong or sick with them. They will be beautiful in the spring.

As they grow in, they will be a little bushier and fuller and taller. No worries!

I was also going to say, buy a few more to fill in the gaps. Despite convention, they don't have to be planted 6 - 10 feet apart. If you want a dense hedge, plant them close together. Then just let them grow and knit together.

I have a hedge (maybe 150 feet) of the common lilac that was planted in 1900. How much they've grown and replaced themselves over the years, I don't know, but now the main trunks seem to be 3 feet or so apart. In full leaf, the hedge is so dense no one can see in and I can't see out. And the blooming in June is spectacular beyond belief.

They're all of uniform height, probably 15-16 feet. Every ten years or so I have an arborist work on them taking out any weak or dead wood. I've never had them topped or the old spent flowers deadheaded after blooming. And pretty much leaving them alone has never affected the massive bloom.

Thanks everyone for the helpful comments. I will fill in a couple of spots and then let it do it's thing.
-Sprout

Sprout- Sorry I didn't comment sooner...but had computer problems last week. I agree with what's already been said. You have a nice start to your lilac hedge, just add a few more bushes and let them fill in together.

Our hedge is a mixture of different shades of lavender and purple with some white thrown in. This is a pretty combination, but all one color would look nice, too. It depends on what you want to have in your yard...which looks very nice in your pictures :)