Guest post by Maureen Gilmer, author of Palm Springs-Style Gardening, on the subject of cactus abuse.
Clark Moorten, my long-time mentor and only child of devoted cactophiles, was born sixty something years ago in our desert here in Palm Springs. He knows more about the Cactaceae than everyone I know put together. And we like to call ourselves People For The Ethical Treatment of Cactus (PETC). We are appalled at the many ways these plants are routinely cooked, drowned and discarded by the ignorant, and that includes many accomplished horticulturists. Are you guilty of unethical treatment of cacti? Read on.
If I see another “hoodia cactus” reference I’ll break out in a rash. Hoodia is an African succulent of the Milkweed family, while true cacti belong to one family, the Cactaceae. All of them are succulents exclusive to the New World.
Another real sore spot is the sight of a saguaro ripped out of the Arizona desert and planted in a residential site. There’s a reason why their roots are so thick that the workers must hack them off with an axe. When transplanted, Clark explains, most saguaros suffer a very long, lingering death. Sure, the new transplant seems to grow, but this is just residual energy in the plant. Eventually it runs out of gas and becomes a dead cactus standing.
Routinely the ever-popular golden barrel cactus are put out into the noonday sun here in the desert. Modern architecture lovers think they’re like some sort of ceramic sphere that can decorate any place in their landscape. All over town I watch them go from a beautiful fat specimen to a shriveled brown mass in the course of a single summer or two. Yet everyone does it because hey, aren’t all cactus made for direct sun? Truth is there are cacti native to nearly every ecosystem from the tip of the Andes to the shaded depths of the Amazon, from the cold Rocky Mountains to the sweltering humidity of coastal Mexico.
Just because some cactus grow in the desert doesn’t mean they don’t need water. One Opuntia is found in Iowa cornfields and many Gymnocalyciums are water loving forest plants. Cactus need water, especially in the summer when cactus plants do most of their growing In the desert, rainfall from summer thunderstorms is the most reliable source of moisture and the plants grow very quickly for a short period directly afterward. It’s the same in the garden with growth spurts and flowering right after I water. Without these regular drinks, the plants stop growing and eventually die of dehydration, the most common reason for cactus death in cultivation. More cactus die from dehydration than any other cause.
Clark and I also grumble about the state of bagged “cactus potting soil”. It’s got a ton of woody matter in it and the bits of wood suck up moisture like miniature sponges and hold it for a long time. We all know fungi grows on this woody stuff. And what is the biggest threat to succulent plants? Bacteria and fungi. Potting soil manufacturers love woody stuff because it’s cheap and light weight for lower shipping cost compared to soils that are the consistency of riverbed gravelly sand that most cacti love. That’s why the potting soil can make cactus so easy to over-water. If it’s any help, my cactus do best in almost pure sand out of our desert river beds.
The fact that cacti are not animated plants somehow causes people to think they don’t need to be fertilized. These desert dwellers need food just like any other plant and they grow really fast if fed lightly every time you water. Porous soils in the wild aren’t very fertile, but nitrogen-enriched runoff or rainfall feed cactus every time they get water. Naturally they’ll want the same treatment in the garden or pot too.
And so the massacre continues, as these amazing plants are starved, burned and drowned in a torrent of misunderstandings. And people wonder why they never grow larger…