Um, I must be sleepy. What do you mean by "prettier"? Shinier? Some roses don't have shiny leaves, some have matte leaves. Some have smooth leaves, others are crinkled.

In my experience, using a liquid seaweed with my fungicide spray has given the leaves on my roses more substance (thicker and larger). But, that's about all I can think of.

On cut roses, some people use a leaf shine product to make the leaves glossier, but I've never hard of anyone using such a product on the leaves on a plant outside.

I really believe Epsom Salts, help with producing good foliage. Since I have been using it, the foliage is more noticably healthy. I could be wrong, but that is my theory. Some rose naturally have particularly beautiful foliage. What comes to mind with me, is Princesse de Monaco, which has absolutely gorgeous deep olive green shiny leaves. Also I find most Harkness roses have incredibly shiny foliage. IMHO

Pauline - Vancouver Island

I'm really beginning to appreciate some of my roses just for their foliage. Diana Princess of Wales has very nice dark green/violet foliage. And now I'm noticing some teas have reddish stems and thorns which are very attractive.

I think you may want to simply hose the foliage down periodically if you can. That will help keep them hydrated (along with ground watering of course) and wash off any dust, insects and possible fungus spores. I also regularly remove any yellow, spotted or simply ugly looking foliage.

I haven't tried Wilt-Pruf yet, but that is supposed to coat foliage to keep it from drying out. I'm not sure if it makes them shinier.

Buford, when we used wilt-pruf (admittedly some years ago) I found that it left unattractive white residue on the leaves.
It is, of course, possible that our alkaline water had some bearing on that, but it for sure didn't make things look better!

Just hosewashing foliage leaves alkaline water residue here.
Even with that, though, the foliage looks better without dust and dirt on it.

Jeri

I'm really beginning to appreciate some of my roses just for their foliage.
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Same here. I have ten potted roses lined up outside my front door and none are blooming yet exept the mini. They nearly all have buds though execpt Rosa Mundi who is FINALLY waking up. I am appreciating the healthy green bushiness of them, the variations from gallica to Hybrid Tea to H. Musk and Austins etc and how attractive that is, in an understated way.