Mark Anderson expounded:

Last year I grew Chianti sunflowers and they turned out nice. This is my
first time growing the massive sunflowers which can grow 10' high. I put
them in 16" and 18" deep pots thinking that these sunflowers would grow
deep roots to support itself. Which brings up a different issue I have.
I really wish those plant tags that accompany seedlings you buy from the
store would also include root depth and width. They say how high the
plant gets and how wide but in container gardening it would be useful to
know how deep of a pot that plant has to be planted in.

No, they're roots aren't really deep, they're wide. I guess they just
expect you to know, or to look it up somewhere.
--
Ann, Gardening in zone 6a
Just south of Boston, MA
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