NO, cacti don’t all grow slowly… Though many people think so, and wait years before noticing a change after planting a golden barrel or prickly pear. The truth is much more varied, which can work against you if you’re building certain look in the landscape. Some cacti grows fast; some grow slow. Knowing the difference will help you design garden that evolves as you’d like it to.
The above infographic details the rate in each category. But it also shows an unexpected ranking based off growth habit (as opposed to just the species name). The fastest growing are climbing things, like vines and viney things like dragon fruit. When well-supported, they can adds almost a couple feet a year. Makes sense biologically, as it’s not like they’re trying to build a heavy woody structure that will stand on its own. Instead, they’re stretching out flexible stems that uses fewer resources to make.
Do Cacti Grow Slowly?
Giant columns and barrel cacti focus more on weight and strength then size. They’re erecting armor. It takes time.
Knowing this, you can get real about your expectations. Want something tall now? You want a column (fast ones = San Pedro; quick vines). Want a thing that already looks solid and ancient by next summer? Wrong plant.
But there’s another huge variable: seasonality. As the chart shows, summer is the time that most growth occur (the “metabolic engines” run at their highest). For virtually every species, summer contribute the majority of its annual increase. In some cases it represents close to half of the year’s improvement. Spring and fall have their contributions as well; winter and the cool months are primarily about preserving what you’ve got.
That’s why you want to water when they need it, not according to the calendar, such as dumping water on a cactus in the middle of winter. Their soil will be wet, and their roots will be dormant, which means the roots can actualy rot before being able to absorb any moisture. Water smartly by matching up watering times to the active growing period.
Slow grows take patience as their coin of exchange. A golden barrel or a fishhook cactus might only gain an inch or two a year. But over a decade, that slow pace add up to a plant with real presence. These things takes time. They repay the waiting gardener.
If the infographic makes anything clear, it’s the tradeoff: the vine’s fast growth versus the barrel’s crawl of decades. You can have long-term character or instant gratifiction. From one plant you could of had both.
The things you have some control over are light and good drainage, the levers you can pull to increase whatever rate the particular species you’ve chosen is capable of. Most will grow best in full sun. A little shade might be okay and could even keep plants alive. However, it won’t produce as much of the dense and compact tissue you think of as a healthy cactus. Good drainage is another key factor. Let the soil dry out between waterings so the roots remain oxygenated and active. Growth stops if they’re stuck in mud.
So: how do you pick a cactus? The answer comes down to matching the plant’s own tempo with yours. If you want a green-fruited vine to cover a trellis within two years, choose the vine. If you’d like an aged-looking yard in 30 years, get yourself some barrel cacti. That’s where the chart helps; it lays out the rates side by side making the choice clear. It removes the mystery, and gives you data that’s usable. With the proper choice of species for the task at hand, there’s no need for a slow-growing garden. All you need to do is know which cactus does what…and when.