What advice do you have for growing sunflowers to be ready for an event?
We would like to grow a variety of sunflowers, from the tall ones like Burpee Mammoth to shorter ones like Santa Lucia as well as smaller multi-stemmed which we can put in vases at an event. We’d like the flowers at the stage where their yellow ray petals are in best appearance (i.e., ornamental flowers rather than in seed production).
My questions are:
-When should we start our seeds to get the best chance of them being in bloom in mid-September?
-Are sunflowers best grown from seed directly sown or seedlings started in 6-packs?
-Can you suggest best varieties to try?
Pamela Hargest, Horticulture Professional
As for when to start sunflowers, it’ll depend on the number of days it takes for them to reach maturity (or bloom). This will be listed on the seed packet as well in seed catalogs. Sunflower varieties can take anywhere from 50 to 95 days to reach maturity with branching varieties flowering longer into the season. I would suggest selecting a pollenless (hybrid) branching variety and doing a couple of plantings a few weeks apart to ensure the sunflowers will be ready for when you want to harvest them. Keep in mind that if the weather cools down in September, their growth will also slow down so that should be considered when you do your plantings. Generally, I would suggest doing a couple plantings between late June and early/mid-July, depending on the days to maturity (dtm). A couple of varieties that I’ve grown and enjoy are Gold Rush (hybrid, 60-65 dtm) and Soraya (85-95 dtm).