Echinocereus coccineus Plains form - Tioga, CO
Echinocereus coccineus from Tioga, Huerfano county, CO is a real oddball in that they grow on the plains in clay soil. These plants are very exposed can take some serious cold with a record low of -36F nearby. This area also commonly has high winds up to 100mph and even snow in early June. Plants are generally squat and many stemmed, females are always larger than males in this species.
I do not guarantee these in a zone 5/6/7 because everyones growing conditions are different but this would be a good trial plant to grow in your cold outdoor garden. Try to plant outdoor 90 days before 1st hard freeze.