Vigorous shoots with no flower buds by late June would likely be first-year canes of the rootstock variety.

So, let me see if I understand correctly: those non-blooming canes you have lived over from last year, and last year, they bloomed? Is that right?

Yes. Last year they were definitely blooming. When I did prune in early spring, I only pruned out winter kill and from what I remember there wasn't much on Heritage.

'Heritage' is normally very free blooming. If you are sure my guess was wrong (scion part was winter-killed and only rootstock grew out this spring), this is baffling. You can hardly keep a repeat-blooming rose from flowering in June if it has enough moisture to grow at all.

Thanks. I am baffled, too. Even my roses with significant winter kill all bounced back and everything I have read has indicated Heritage is pretty foolproof. I'm starting to take it personally like perhaps she just doesn't like me. ;)

I have two of Heritage. One got hit pretty hard by the bad winter (this will be it's 4th year), and in early spring looked pretty sickly. I noticed when it bloomed that half of the canes did not bloom at all. My other Heritage is fine, and previously they both bloomed well. I would not shovel prune! Heritage is very lovely. I suspect the cold weather at this point.

If the old canes are only supporting puny growth (small, crowded leaves and short stems), then maybe they were winter-damaged and you needed to prune more aggressively in spring.

In my case, all of the canes looked weak in early spring. But the canes that ended up not blooming ended up looking every bit as healthy and vigorous as the ones that did bloom...

You probably have what is known as "blind shoots." I copied this definition from a website which I cannot name.

"A blind shoot is a fully grown or developed shoot that fails to produce a flower.

A cool spring most often is the cause of blind shoots. Although they may appear anytime during the growing season.

One way to detect a blind shoot is that instead of a flower bud at the end, there is a group of small leaves that look similar to a husk of wheat.

To remedy a blind shoot cut it back by half its length, new growth should grow and flower normally"

Hope this helps.

Thank you! I'll take a look tomorrow to see if blind shoots could be the problem. I also took a look at my local public rose garden a couple of days ago and Heritage is blooming beautifully there.

I've been meaning to post. Thank you to all who offered advice. DavidBeck was right, blind shoots were definitely the problem. I pruned them in July and I now finally have some blooms! So grateful for this forum and your help.

Could it be rose midge? My Heritage, which has been free flowering/in constant bloom in past years, hasn't done much this year because of rose midge. Looks at the tip of the shoot, and see if you see the tiny dried up/shrived tips.