Echinocereus rigidissimus is a fast growing species of hedgehog cactus from southern New Mexico. It prefers afternoon filtered shade. These plants definately grow a healthy amount in the monsoon season. The seed was collected in the pelloncillo mts of NM. Thes survived -17F this winter but prefer slightly warmer to get large size. These plants can get 18" tall in prestine conditions.
Plants pictured are what is for sale.
I do not guarantee these in a zone 4/5/6/7 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.