CACTI OFFER HARDY BUT BEAUTIFUL RESULTS WITH ALMOST NO MAINTENANCE REQUIRED
\A description of a perfect plant would go something like this: never needs to be watered, tolerant of the coldest winters, not bothered by pests, produces gorgeous flowers. Such a plant sounds too good to be true, but it does exist, and it’s even native to Canada. The plant, of course, is the cactus.
Now, I know that many gardeners would never consider growing cacti in their yards. They are a bit of an acquired taste, but I think these fascinating plants deserve a second look.
In the drier regions of the Canadian prairies, we have three native cactus species: Opuntia polyacantha, Opuntia fragilis, ( both commonly called prickly pear cacti) and the pincushion cactus, Coryphantha vivipara. Prickly pears are quite common in southern regions of Alberta, Saskatchewan and Manitoba, but there are also plenty of them on the south-facing banks of the Peace River region.
Our native cacti are the toughest of plants — able to endure extreme cold, heat and drought. In early summer, these cacti put on a beautiful (if brief ) display of stunning flowers. The blooms are mostly yellow, but they also come in shades of pink, orange, red, and even apricot and white, with the flowers giving way to edible fruit later in the season. The fruit of coryphantha species is very sweet — much like kiwi fruit — with opuntia being a little less sweet, but still flavourful.
Prairie cacti, like most cacti, have developed a very interesting quirk that allows them to manufacture food even during extremely hot, dry weather. While most other plants take carbon dioxide into their leaves during the day, cacti absorb carbon dioxide at night and convert it into sugar the following day.
This nocturnal gas guzzling makes sense for cacti. If the cacti stomata (tiny pores in leaves that exchange gases) were open during the heat of the day, they would absorb carbon dioxide, just like other plants, but they would also lose a huge amount of water. So, instead, cacti simply trap and hold carbon dioxide during the night and then use it as a sugar “building block” during the day.
Because prairie-hardy cacti aren’t large and showy, and to add some interest, they are best displayed with other xeric (droughttolerant plants) such as hens and chicks, sedum, and hardy yucca. Ideally, the xeric garden should be on a south- or southwestfacing slope and contain sandy soil to drain water easily. Don’t worry about keeping a garden hose handy, you won’t need it. I have one cacti in my yard that I watered about 10 years ago.
Even thought cacti are the prototypical xeric plants, they still need some water. In fact, they are gluttons for water if given the opportunity. In their natural environment, cacti absorb and store every drop of water they can; in areas with very limited rainfall, this is the only protection they have against long periods of drought.
With some species of cactus, a “pad” broken off of the main cactus can survive for years without any water or roots. Once planted into moist soil, it will resume growth.
Cacti certainly aren’t suited to everyone’s taste, but they are worthy of consideration for those who like unusual plants that are easy to care for. And for those gardeners who have a problem with cats digging in their gardens, cacti work better than any repellent on the market.