This was my first attempt growing dahlias. I only had a 40% germination rate, but the plants that did come up grew very well in my short raised bed with a peat-based mix. Slugs and Japanese beetles did not bother them! I did make a mistake by planting them too close, so heed the spacing suggestion. The plants had many 2" blooms starting mid-summer and had 6-10" diameter crowns when I dug them in fall. I also harvested a ton of seeds, as I did not deadhead them late in the season. I haven't tried sprouting them yet, so I don't know if they are viable.
Thank you for sharing your growing tips on the Showpiece Mix Dahlia!
Thank you and Happy Gardening ~ Deby