Up to the late 90s in my Denver yard, this cold hardy yet heat tolerant annual came up each year by the hundreds from fallen seeds in the bed between Willow Street and the sidewalk. They would get 5-8 feet tall and would arch and make a tunnel over the sidewalk the kids used to like to walk under. One year I got cited by the city of Denver for having too tall of flowers by the sidewalk! No scent but lovely and graceful in my garden and clients' gardens.
By the late 90s I stopped their growing there as by July they'd begun crowding my roses. EXCELLENT bee plant. I donated some seeds to that CSA community garden in Boulder for their hives one year. I got the seeds my first summer in Denver, 1988, from "Nebraska farm girl" Vi Stoughton over on Xanthia Street, then well into her 70s. It was one of many welcome- to-Denver seed gifts she gave me. Botanically it is Polygonum orientale, but I laugh to remember in those early days of a STEEP and heady learning curve I somehow called it an amaranth and shared the seeds as such. I can't believe how little I knew botanically back then at 33!
I am likely treating myself to a second live bees purchase in March from a LOCAL bee seller (I threw away $60 two years ago to a crooked/inept bee seller in Georgia/Michigan who even ignored the BBB when I filed a complaint) plus I always did like this flower in Denver. Seeds I brought with me from Denver never did sprout, so I ordered some from a great catalog this winter. Five seedlings are up so far, and I just planted two in a buried 4 gallon Water Wise Container Garden in a bed I just revamped on the east side of the big pond out back. Each spring in Denver the seeds would sprout VERY early and endure incredible late freezes and snows unfazed, so I figure in this oddly cold, quasi-wet winter, now seems a good time to try again. Oddly, the mature plants thrived in Denver's hot summers.....I will be curious how they fare here in humid heat. With a new cold front coming I will plant the rest of the seeds today in a pot for insurance as I'd love to grow some out front to wow passersby as I have never seen it in Florida. It is a close relative of Buckwheat, and the seeds are edible......IF it will grow well for me both the leaves and the seeds could be great chicken fodder. Plus if I splurge and buy the live bees for my Top Bar Hive in March, they'd have a great nectar and pollen source right here.
Here is a link to a page with some nice photos and data about this charming heirloom flower. Enjoy, John