Hello, my Cupid's Dart (Catananche caerulea) plants are not flowering and I wondered if you might be able to help. I purchased two plants (about quart-sized) from a plant sale at Cylburn Arboretum in early May, and planted them with Catchfly purchased from the same sale in self-watering window boxes (excellent drainage) in full sun, watering 2-3 times per week. I used organic outdoor potting soil and the recommended dosage of Jobe's organic flower food. (Later I added in some Veronica Speedwell and Liriope muscari into the window boxes, but by then the Cupid's Dart were already struggling.) The Cupid's Dart grew well and looked healthy, but then, just as the buds appeared ready to open into blooms, they all began to wilt, droop, and brown. Eventually (3 weeks later?) I noticed aphids along many of the stems of the Cupid's Dart; I have applied a neem oil spray weekly since that time. About two weeks into the neem oil treatment, both Cupid's Dart plants put out 2-3 flowers, but then returned to their sorry state. No flowers since. I've read online that Cupid's Dart is notoriously simple to grow, and perhaps as a consequence I haven't been able to find any 'troubleshooting' articles or blog posts addressing common problems. Any insight you might be able to offer would be greatly appreciated. Thank you!