Coryphantha robustispina ssp. uncinata Truth or Consequences, NM
Coryphantha robustispina ssp. uncinata is a species from southern New Mexico that has proven very hardy in Colorado. Plants have taken -22F and negative teens. The trick to this species is sandy soil and good drainage. Plants bloom in mid to late Summer and have honey smelling flowers. Stems can get 8" across and can mound.
I do not guarantee these in a zone 5 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.
Shipping: Packages can be held for a specific date. Please see our shipping section for information.