Many cacti are well-suited to warm areas of the U.S. Yet, there are some winter hardy species that thrive in northern climates.
Choose the right plants, and provide them with proper drainage. Success should follow.
Start by choosing a site with a southern exposure if possible. This will provide the plants with the sun they need. As an alternative, eastern and western exposures are satisfactory.
For the best possible drainage, plant the cacti in a raised bed with sandy soil, or on a bank or slope. In any case, a quick-draining soil is essential. The plants won’t survive in a spot that remains wet for long, particularly during rainy weather and the spring thaws.
Here in the North, there is no need to fertilize or water cacti. In some years, the summers may be dry. But our plants are able to survive drought.
During the fall as our days become shorter and cooler, the cacti will begin to shrivel. Don’t be alarmed. This is normal. It just shows that the plants are preparing themselves for the winter ahead by reducing their moisture levels. During spring when warm temperatures return, the shrunken cacti will fill out again and resume growth.
Established winter hardy cacti need no winter protection whatsoever. Heavy snows won’t hurt the plants. In fact, they insulate the plants from drying winter winds.
Though it is true that most desert cacti aren’t winter hardy, a number of different species will survive in cooler areas. They include species of ball cactus, barrel cactus, prickly pear, and other kinds of Opuntias.
Members of the Cactus Club of Jamestown, NY have had success with two different species of ball cacti. These are Coryphantha arizonica and Pediocactus simpsonii. In addition, John Shelley’s Garden Center and Nursery, located in zone 5, recommends two varieties of Escobaria vivipara, as well as Escobaria missouriensis.
Several species of hedgehog or barrel cacti thrive in this area. The folks in Jamestown recommend Echinocereus engelmannii, Echinocereus triglochidiatus, and Echinocereus viridiflorus. According to Shelley’s, Echinocereus baileyi is hardy for the area.
So far as the other kinds of Opuntias are concerned, the Jamestown club found Opuntia imbricata was hardy in the area. Shelley’s also recommends two different chollas--Opuntia kleiniae and Opuntia whipplei.
For the most part, the most commonly grown cacti in the area are the pad or prickly pears. The most hardy of all seem to be Opuntia compressa, said to be hardy to –50 degrees Fahrenheit (zones 4 to 7), Opuntia macrorhiza (zones 4 through 7), and Opuntia fragilis-hardy as far north as zone 2.
Shelley’s recommends the following Opuntias for zone 6 include Opuntia polycantha, Opuntia basilaris var. aurea, and Opuntia phaeacantha.
In addition to the ones above, the Jamestown cactus club recommends Opuntia rhodantha and Opuntia picnantha.
Shelley’s website (www.gdnctr.com/cactus.htm) offers descriptions and photos of winter hardy cacti for zone 6. The garden center has a hardy cactus garden as part of their display gardens.
Cactus lovers gardening in cold climates would probably benefit from a membership to the Winter Hardy Cactus and Succulent Association (www.cactus-mall.com/whcsa/). With membership you receive the color-illustrated quarterly newsletter in which members share their gardening experiences in zones 3 through 6.