I grew amaranth from seed one year and for several years had volunteer plants as it self seeds. Your plant looks great.

I had a gorgeous Love-Lies-Bleeding last year. I winter-sowed seeds from it and other green amaranth, hoping for another spectacular display. Unfortunately the one survivor of this experiment (planted out at 6 inches) is still tiny, with a miniature tassel. I am new to this, but my tentative conclusion is that wintersowing in my zone (6b) is too late for this plant. Anyone else with other thoughts?

I fed my amaranth miracle grow fertilizer along with other plants. And that might have contributed to its robustness. Also, I think it likes hot weather. And it doesnt need a lot of water. I dont think it needs wintersowing. My plant was less than 6 inches tall at the beginning of June when I transplanted it.

Too enthusiastic a grower. Was finally able to eradicate

I have another volunteer in a slightly shadier location whose leaves are dark maroon. And the one in the front bed which has greener leaves is in full sun, but it started out with the same dark red/maroon leaves. So it is possible the leaf color has something to do with the amount of sun.
I have seeds of celosia 'Forest Fire' and Celosia Kurume Scarlet, which I plan to use along with the Hopi Red Amaranth and Purple majesty millet, next year.

10 bean seedlings, 10,000 amaranth... plus a few crabgrass. The joys of throwing ripe seedheads into the compost :)

Yours is a stunner right there at the entry. I tried Molten Fire with Zinnia and will try again next year but pinch the amaranth. It got very leggy and is just now getting the "fire". This photo of a short branch shows my vision for the combination.

They look great together!

My amaranth got knocked down by the storms...