Sept 5, 2016: Mid Oct 2015 I direct seeded Sublime series Azure, Dark Blue, Salmon, and White. No winter protection, in landscape fabric, 6" spacing, no pinch. Planted again mid-Dec and mid-March. First planting bloomed at over 5' tall, with decreasing heights down to about 20" for my March planting.
The bloom window for the whole bed was the end of April to the beginning of June, just a little over a month. What the succession planting accomplished was to give me varying sizes of flower spikes, but the difference in bloom time was really only a couple of weeks or so between the first and last plantings.
Flower spikes are very geotropic, I found out quickly. The tips bent toward the ceiling in my cooler if the stems were stored anything but straight upright. White sold to florists, the salmon a little. All colors are useful in grocery bouquets, although I did find the salmon a little hard to match up with some of the bluer pinks I was getting in other flowers blooming at the same time, Amazon dianthus 'Rose Magic', for instance.
Although I ended up with some impressively large flower spikes, pinching would probably give me more usable bouquet stems. Those spikes are only going to be useful for church urns or some other giant (rare) installation. This year I'll make one fall sowing and pinch.