benwbutler
Newly Registered
Posts: 1
Joined: Sat Jun 10, 2017 6:28 pm

Sunflower bloom time relationship with daylength

Hi there. I'm getting married on our family farm in Maryland on Sept 16 of this year. Every year we plant a few acres of sunflowers using a no till drill, for our pick your own customers to enjoy. I'm trying to time the flowers this year to be in peak bloom on (or near) my wedding day. I usually plant the sunflowers in a few plantings between mid June and mid July, with peak bloom usually being around mid august. Of course the varieties have a lot to do with the days to flowering, but I am concerned that day length in August and early Sept. will cause the flowers to bloom early, regardless of the specified "days to flowering" on the seed label.

Do you have any suggestions on how to predict how day length will effect the flowering timing? All suggestions are welcome! I will have to look at pictures the rest of my life, so I'm really trying to get this right.
Thanks!
Ben

imafan26
Mod
Posts: 13962
Joined: Tue Jan 01, 2013 8:32 am
Location: Hawaii, zone 12a 587 ft elev.

Trying to time sunflowers is tricky. I usually am off by a week. My suggestion is to plant a few flowers every few days over 2-3 weeks to make sure something is in bloom. Sunflowers bloom for about 10 days. They are in peak bloom day 4-8 then they start to fade. As the days get shorter it actually takes them longer to bloom. However, my long and short days are almost the same. 11-14 hours.

User avatar
applestar
Mod
Posts: 30514
Joined: Thu May 01, 2008 7:21 pm
Location: Zone 6, NJ (3/M)4/E ~ 10/M(11/B)

It sounds like you would be the expert @benwbutler.... I always thought sunflowers need cooler temperatures to germinate, but you are saying you plant them in the heat, so it seems logical to continue to succession sow like imafan mentioned.


...I can't imagine the mid-July sowing blooming by mid-August... when do those usually bloom?


...I "missed" sowing sunflowers earlier in spring, so I thought it was too late, but based on what you are saying, I should go ahead and try starting them even now. 8)

imafan26
Mod
Posts: 13962
Joined: Tue Jan 01, 2013 8:32 am
Location: Hawaii, zone 12a 587 ft elev.

]I like to grow lemon queen and mammoths they take about 90-100 days to flower. Lemon queen produces multiple flowers over an extended time, but you really can't beat the size of the mammoth. There may be varieties that have shorter days to bloom, but 60 days is unusually short. I would think though that the longer days will get you a larger plant and flower. :cool:



Return to “Flower Gardening & Garden Design”