63 ” 77 days. Sparky Mixture French marigold seeds offer one of the most vibrant and inexpensive blooms available to the home gardener. Sparky Mixture is a familiar alternative to the traditional marigold, quickly maturing to 9 ” 12″ tall boasting unique semi-doubled heads. Marigold seeds are a favorite for kids or novice gardeners because they are a low-maintenance grow tolerant to a variety of difficult gardens. Sparky Mixture marigolds are an ideal grow along walkways, fences, or trimming the back of the garden.