Most succulents are slow growers, but cacti may be the slowest! Most species of cacti grow slowly—even the ones that get huge like saguaros. It can take a saguaro up to ten years to become just an inch tall. That’s a long time for such little growth!
So if you’ve had your cactus for a few years and you’ve barely seen it grow, don’t worry—that’s completely normal! You’re not a bad plant parent, and you’re not taking care of your cactus wrong. Even cacti that are well taken care of will only grow about an inch taller each year unless you have one of the rare few species that grow quickly.
If you want to know why your cactus is such a slow grower and what you might be able to do to support its growth, then keep reading!
Why Cacti Grow Slowly
Soil and climatic conditions
For cacti, slow growth is a matter of survival. In the desert, water and nutrients are incredibly scarce. It barely rains, and the soil is dry and almost infertile. Plants need water and nutrients from the ground to carry out photosynthesis, so the fact that cacti get so little of both means they can’t grow very much.
Cacti have also adapted to focus their limited resources on survival rather than sprouting lots of new growth. They conserve water and resources so that they can survive through long periods of drought and extreme heat.
Check out “The Rounded Ball Cactus— Parodia Magnifica” for a fun look at an amazing type of cacti you can take home with you.
Lack of leaves
Another reason why cacti grow so slowly is that they don’t have leaves. Plants transpire through their leaves. About 99% of the water absorbed by a plant’s roots evaporates through its leaves. So if cacti had leaves, they definitely wouldn’t be able to grow in the desert!
One downside of not having leaves is that it limits their ability to soak up the sun and convert it into food through photosynthesis. Plants with big, broad leaves have more green tissue, which means they have more chlorophyll. Chlorophyll is the chemical that makes plant tissue green, and it’s also a vital part of photosynthesis. Chlorophyll can soak up energy from the sun and convert it into glucose, which primarily plants’ food. Plants are then able to utilize that glucose for energy and growth.
Because cacti only have stems and not leaves, they have less green tissue and less chlorophyll than other plants. This limits their ability to soak up the sun and convert it into food that they can use to grow. Cacti have spines and sometimes wool on their stems that shade them from the sun, which likely limits their ability to soak up the sun even more. No wonder they grow so slowly!
Stomata in cacti
Another adaptation that slows down their growth is their stomata. Stomata are the pores found on the surface of all plants that allow them to take in carbon dioxide. Carbon dioxide is needed to carry out photosynthesis, so for a plant to grow quickly, it needs to take in a fair bit of carbon dioxide.
Whenever plants open up their stomata to take in carbon dioxide, though, some of the water in their leaves evaporates. Cacti couldn’t survive in the desert if they lost lots of water through their stomata, so they’ve adapted to have fewer stomata than other plants. Because they have fewer stomata, they can’t take in as much carbon dioxide, further limiting their ability to carry out photosynthesis.
All the adaptations that make cacti cool, distinctive plants are the reason why they can’t grow as fast as other plants. Bummer, right?
Can I Make My Cactus Grow Faster?
We bet that you get a little impatient waiting for your cactus to grow—we certainly do! We’ve spent a lot of time researching how to make cacti grow faster. And unfortunately, we’ve learned that there’s not a whole lot that you can do to speed up your plant’s growth without potentially harming it.
Can fertilizer help?
If you give your cactus extra fertilizer or water to try to speed up its growth, it can develop several defects. Giving your cactus too much water could actually cause its skin to split. Cacti have adapted to soak up as much water as possible whenever it rains and store it in their cells. They’ll try to soak up all the water you give them, even if their cells aren’t big enough to fit all of it. This can cause their skin to split as their cells and tissues bulge from all the extra water, which will create an unsightly scar when it heals.
Be sure you also check out our article “5 Dangers Of Overwatering A Cactus” to see all the possible dangers of too much watering.
Cacti also don’t respond well if you give them extra fertilizer. Their new growth will often be deformed, which ruins their appearance. This especially happens with columnar cacti. Their new growth is much more significant and more circular than the growth below it, so it looks like a big round ball is sitting on top of your cute, skinny cactus! They also become very top-heavy and can even fall over if they get this way, so you don’t want to overfeed your columnar cacti to speed up their growth.
What about watering?
You should only water your cacti about once every two weeks when the soil is completely dry. They don’t need much fertilizer either—feeding them once or twice during their growing season will probably be enough given the fact that they’re used to infertile desert soil. But you can safely fertilize your cactus about once every month or two during its active growing season without harming it. Just don’t start fertilizing it every week!
Check out our guide “How Often To Water Cactus” for all things watering when it comes to taking care of your cactus plant.
Which Species of Cacti Grow the Fastest?
If you love to see your plant babies grow as we do, then you might want to get a species of cacti that are known for growing faster than the rest. We’ve heard from other succulent gardeners that Cereus and Trichocereus cacti species are particularly fast growers.
Pilosocereus cacti, a beautiful genus of blue cacti, are also known for being pretty fast growers. Go check out the article we just wrote about them to learn more!
It’s a bit of a bummer that most cacti grow slowly, but trust us—their growth is worth waiting for!
Also, be sure to check out “Totem Pole Cactus (Pachycereus Schottii Monstrosus)” for another type of cactus to get you excited over.
We hope that this article has answered all your questions about how fast cacti grow. But if not, feel free to leave your questions below or ask them in our awesome community of succulent lovers, the Succulent City Plant Lounge.
Did this article help answer your succulent-care questions? We sure hope so! If not, no worries. Succulent City is devoted to aiding all succulent lovers, and that’s why we created a line of ebook guides! Check out our in-depth tips on “Essential Tools for Planting the Best Succulents” or even “The Most Common Issues Amongst Succulent Growers” today!
Hey everyone! Welcome to Succulent City! We are all about succulents, cacti, and a bit about air plants. Ten years back, in 2013, we began the journey with succulents. It started as a simple hobby, crafting and selling charming succulent-themed pins and decorations. But as time passed, our fascination with these remarkable plants grew, and we gained extensive knowledge about them. Therefore, Succulent City is the blog as you see it is now. Enjoy your visit and happly planting!