I mentioned a plan similar to this to DH the other day.
We planted a small circle (approx. 7 to 8 ft diameter) of sunflowers out near the street this year. They've grown to approx. 6' tall and six or seven of them have bloomed; three or so haven't yet but will soon.
I told DH that my plan was to cut off the sunflower heads (seeds) after the pollen run--LOTS of bees are visiting!
--and leave the stalks to support other plants next year. (I also put DE near the bases of the stalks b/c ants
as well as the bees
were starting to take notice of the flowers.)
We have some ne'er-do-well hollyhocks inside the sunflower circle. Maybe they'll grow next year. I found out AFTER planting Alcea rosea seeds in April that the plant is slow to start: it would have been better to wait until October to plant. *sigh*
So I'll find out how well sunflower stalks do as hollyhock supports. The last time I grew hollyhocks, they were planted against a dark-colored, south-facing wall of our former house. They grew to 15 feet.
I doubt that these will get that high; they're subject to passers-by and afternoon winds. No nice, warmth-reflecting surface nearby, either.
But 6-foot-tall sunflower stalks ought to give 'em a leg up, huh?
USDA Zone 9, Sunset Zone 17