With its dark red stems and yellow to poison-green inflorescences, sun spurge is a striking wildflower. It grows as an annual, either from fall to early summer or from spring to fall. Its main flowering season is from March to June.
Like the unrelated sunflower, sun spurge can turn its flower shoots to face the sun. Flies are often seen on the flowers, but they are also visited by many other insects.
Euphorbia helioscopia is well adapted to survive in the cultural landscape, colonizing meadows, banks, roadsides, gardens and fields.