Aimee Stern. I have been working with scientists and engineers on explaining their research and other work to the general public for almost a decade. I've explained the science of many things and how they connect to the real lives of real people.
Sunflower seeds are best sown outdoors directly into the garden. After planting, cover them with a screen, as the birds and animals love to dig the seeds out. You can also start them in a seedbed and transfer them when they are small. If you plant sunflowers indoors, use individual peat pots. Start two to three weeks before the last frost date for your area. Plant one or two seeds per pot, thinning to one before planting outdoors. If you grow them to feed the birds, look for seedlings growing near the base of last year's crop.
Characteristics. It takes about 11 days for an annual sunflower seed to germinate and appear through the soil, and roughly 90 days to reach maturity. Sunflowers attain their maximum height in about 50 days, followed by head development and seed production.unflowers are fast growers capable of reaching their maximum height in one season. All varieties of annual sunflowers (Helianthus annuum spp.) do their growing during one year. Depending upon variety, this can mean a plant that grows to just 2 feet or one that grows to 12 feet.