To sow the seeds, wait until about eight weeks before the last predicted frost date in your area. Any smaller, tan-colored seeds weren’t pollinated and they aren’t going to be viable. They’ll be plump and dark brown or black. When it’s completely dry, rub the pod between your hands to release the seeds. As the outer parts of the pod start to turn dark and dry, harvest it and place it in a cool, dry spot. Once a pod plumps with a dark, dry center at the pointed end, it’s about ready. That means no cutting the flowers for arrangements. To collect the seeds, wait until the pods form on the stem after the flower fades. You can collect them from existing plants but these seeds won’t grow true, meaning the resulting seedlings won’t necessarily look like the parent plant. You can purchase dahlia seeds at many retailers, but you won’t find dinnerplate seeds. Propagationĭinnerplates can be propagated in all the same ways that other dahlias can be.īuying a live plant or tubers is the easiest way to go, but propagating cuttings or taking divisions is a good way to save a buck or reproduce a specimen that you particularly like. The plants themselves typically grow over four feet tall and almost all of them require staking, since those giant heads are heavy – usually heavier than the stems can support. The first blossom of the season is usually the largest, and any successive flowers on a given plant will typically be smaller. It doesn’t denote a particular species or group of cultivars.Īnything that can grow at least eight inches across is considered a dinnerplate type and they’re all hybrids, usually with the hortensis species somewhere in their lineage. ‘Thomas Edison,’ ‘Kelvin Floodlight,’ and ‘Snow Country’ are some of the oldest cultivars still on the market.īut don’t feel deprived – the newer dinnerplates are big, bold, and tougher than ever before.īy the way, “dinnerplate” just means that the flowers are large. By the 1920s, dahlias were all the rage in the US and Europe, and many new dinnerplates were bred. Those flower-breeding superstars, the Belgians, started creating the first dinnerplate dahlias in the early 1800s. As ornamentals, dahlias were a bona fide winner.

Dahlia botrytis blight