Sod is the fastest. That said, if you don't have a ring of something around the tree, you'll have trouble mowing. You could cut the grass near the trunk carefully with clippers. I'd put a ground cover in, instead, if you don't like the look of mulch. I like moss phlox. You could get some plugs and fill in with annuals until the phlox spreads. You can always have a much smaller ring.

That large mulch ring kept the weed-n-feed away from the hydrangea.

Neither the plant nor the mower will like grass under there. Who does the mowing?

tj

Thank you all for this great info - I didn’t think about the mowing and you are right! I think I will just make the circle smaller and even out the ground with sod. Now on to find a place that will sell small pieces of sod!

I wouldn't make the mulch circle any smaller. It is in perfect proportion to the hydrangea. And it is not a standard or tree form....just a shrub :-))

If you don't like the look of mulch, just plant a low, non aggressive groundcover. Geranium 'Biokovo' would look lovely there.

I love wild geraniums. It’s a lovely idea!

G. 'Biokovo', while a lovely groundcover is not a "wild geranium."

Whoever planted that was a gardening pro. I suggest you get a book and read about the importance of leaving clearance beneath any shrub and tree you plant. The only place where that would not be necessary would be in a flowerbed with a mix of shrubs, perennials, and annuals. Underplanting in that case would be okay and sometimes beneficial in keeping the roots cool, especially in a sunny bed.

Is that a photo of what the plant looks like now? If so, I suggest you leave it alone. Don't mean to sound insulting, but your question makes clear that you are not a pro and would probably do more damage by cutting it back than help it and it would take years to get it back to the graceful beauty it is now. These plants are not supposed to looks spherical and perfectly shaped. They are supposed to look natural flowing gracefully like that of all different lengths. That is a perfect example of a Specimen. Which means, it is so gorgeous and perfect that it is supposed to be alone and a focal point. So, just leave it alone. I suspect that if you mess with it, you will live to regret it. If you can't control your impulse to destroy it then just apply more mulch (away from the trunk) or you can plant around the edge with some groundcover like impatiens. But be aware, you will be damaging the root system with whatever you plant underneath which will cause parts of the plant to die off.

For heaven's sake!!!.......let's not get carried away! Surrounding the hydrangea with some sort of groundcover is not going to make "parts of the plant die off". You might get some minor root damage but not enough to cause any concern and they will regenerate quickly. It is also an entirely common practice to prune panicle hydrangeas like this on an annual basis.

It might be best to be 100% sure about the statements you make before you start criticizing someone for their thoughts.

You only remove deadwood and old blooms on a Specimen plant like that. Since it is a Specimen it really doesn't need any other adornment. It's perfect on its own. Why risk any injury by underplanting it?

1. Underplanting the hydrangea is not going to risk anything. They are often included in mixed borders underplanted by a whole host of other plants.

2. Your definition of a "specimen" plant must differ from the standard as most horticulturists would not consider a modestly sized panicle hydrangea shrub as a specimen.

3. There is NO reason a specimen - if that is what it is truly considered to be - should be treated in any way differently than the same plant if combined with others. They still require the exact same care and attention.

You have a very beautiful plant, nicely and correctly mulched. The simplest and easiest thing to do is nothing. Why mess with perfection?

Wow, I didn’t realize I would be insulted for asking a question on a forum! I was just asking for advice and didn’t say anything about being a pro. Anyway, I have had mature limelights before and they actually should be cut back every year and respond very well to pruning.
Thanks to all who offered kind advice - I’ll make the mulch circle smaller and even it out as some have suggested. I let you know if I decide to underplant with anything - I do like the idea of geraniums. Thank you!