Burning Hearts (like many of its hybrid brethren) is a finicky plant. They like a rich organic soil that drains freely. If they are too wet they will rot, too dry and they will turn crispy quickly. It is a compact long-blooming plant for the front of the shade border. Other varieties in the Hearts series are not typically long-lived, lasting only a few years, and I expect Burning Hearts to be the same. The parent plants of the hybrid can be short-lived as well, but they are self-seeders and you don't notice the parent plant dying out. The hearts series is sterile, which causes it to bloom much of the season. Even if it only lives a couple of years, it's worth the long season of color for the shade IMO. Also keep in mind, all of those flowers take a lot of energy, and regular weak fertilizer applications will help. The Plant Geek www.confessionsofaplantgeek.blogspot.com

This link should answer you questions :) Here is a link that might be useful: Missouri Botanical Garden

I think your on the right track . I would give fert. to the smaller ones this year and cut back the bigger ones a little after they are done blooming. I used miracid every two weeks last year to push growth on a small hydrangea last year and it worked well. Its as big as its brother. Its flowers changed color this year though.

~~ BUMP ~~ I was wondering how everybody's Dazzler was doing after the 1st year??? I successfully rooted a cutting late last summer, and it has been blooming this summer for the last 6 weeks. First of all, before any leaves the plumie put out, she had several small bright pink blooms. Dazzler is still blooming in August, is graced with leaves, and her blooms are getting progressively larger! This morning I measured a brightly colored pink bloom w/a golden eye at 5.5 inches. It is very rootbound, and once the blooms stop, I will get her a much needed larger pot. I can only imagine how she will do the 2nd year once I give her more room to grow. Her blooms are so bright--very eye catching!! This one's a keeper! ~Mary Jane