The cactus is a great beginner plant because it doesn’t require a lot of attention from you. They don’t need to be watered too often and are versatile enough to survive in most conditions. You are likely wondering how long it will take your cactus to grow, and how big it could end up being. It’s worth knowing this information so that you know how much room to give the cactus.
In general, a cactus grows very slowly. They can take up to 6-12 months to grow to roughly the size of a marble. They can reach a few centimeters after a few years, depending on the species of cactus you have. From there, they grow around 1-3 cm per year. There are some exceptions to this rule, including cacti species that grow as much as 5.9 inches per year.
- The Ferocactus species of cacti grow around 2-3 cm per year on average
- The echinocactus genus, including the Golden Barrel Cactus, can grow up to 1-2 cm per year on average
- The Saguaro Cactus is the exception to the rule; able to grow anywhere between 2 and 15 cm per year in the right conditions. This cactus species can grow up to 75 feet high.
It’s going to take some time to grow a cactus to their full size. Let’s take a look at how long a cactus can take to grow, why it takes that long, and what you can do to speed things up a little.
Why Does it Take so Long for Cacti to Grow?
Two key factors help to determine the growth rate of a cactus. The first of these factors is the fact cacti are built to survive. They have adapted over the years to survive in unpredictable environments that barely get any rainfall. Their energy is primarily focused on the act of survival instead of growth.
Cacti could find themselves in situations where they need to survive extreme heat and a lot of droughts. If they didn’t put such a heavy focus on surviving, they would likely be unable to survive long enough to begin reproducing.
Of course, not every cactus is found in an arid environment. There’s the subset of cacti called the jungle cacti. These cacti have adapted differently than the desert cacti in order to survive their own environment.
The second key factor in cacti growth is their leaves. Well, more so their lack of leaves. All kinds of plants typically have lots of leaves. The leaves can be a wide variety of shapes and sizes, but there’s no doubt they are attached to the plant. Leaves are packed full of chlorophyll, the chemical in plants responsible for photosynthesis. Other plants, with their leaves, have a lot more energy than a cactus and can use that energy to grow.
Cacti don’t have leaves. They don’t even have branches. What they have instead are their spines and areoles. These play no part in producing energy for cacti. Leaves aren’t suited to the harsh and boiling desert environment that cacti primarily live in as they could cause a plant to quickly run out of vital water.
When you put it together, you’ll see that cacti don’t have as much green tissue as other plants do. You may note this as odd, and it is the prime reason why they don’t grow as fast as other plants.
How Much Will A Cactus Grow…
Let’s take a look at the different growth stages of cacti and how long each stage takes. These milestones in cacti growth assume that the cactus lives in a suitable environment that is neither too hot nor too cold, that they are getting adequate sunlight, and that they are tended to and cared for as needed.
One Month Cacti Growth
Much like other plants, cacti begin life as a seed. It could be anywhere between a few weeks and a few months for germination to occur for seedlings. You shouldn’t expect much, if any, growth in those early days.
If you get lucky though, then you might see that their spines start to come in within the first month. With that said, not every species of cactus even has spines. If you have one of those kinds of cacti, then you should keep an eye out for any seedlings poking through the dirt.
Don’t worry if you don’t notice any growth at all within a month. It really can take up to three months for this kind of growth to happen. Owning a cactus is all about playing the waiting game.
It’s important that you remove any coverings from the cactus during the day for this initial growth phase. That allows the cactus to get the ventilation it needs. You should also water it on time. Cacti are best watered when the soil dries out. We’ll go into more depth on this later on.
Six Month Cacti Growth
Your cactus should continue growing as long as you care for it. Even then, you shouldn’t expect it to grow very fast. After around six months, a cactus may still be the size of a marble. When compared to other flowers and plants that can seem like very little growth. It’s likely going to make you worried for your cactus. Don’t worry though, as that level of slow growth is about what you should expect. It’s entirely normal for a cactus to grow so slowly.
Year Cacti Growth
You also shouldn’t worry if the cactus continues to be small even after 12 months have passed. Once they reach the size of a marble, whether it takes 12 weeks or 12 months, you should move them to their own separate pot. They need to have more room in order to continue growing.
30 Year Cacti Growth
How much a cactus grows can vary across different years depending on what species of cactus you have. For example, a saguaro cactus – which are found in the Sonoran Desert of Arizona – can reach surprising heights. They can reach heights of up to 75 feet if well taken care of.
The saguaro cacti are known to sprout flowers across their growth phase. Flowers will bloom within around 30-35 years. They really do live for a very long time.
What Can Slow Down Cactus Growth?
While a cactus is generally slow to grow anyway, there are things that can further reduce their growth rate. Here are potential issues that could be causing your cactus to grow slower than usual;
- Growing it in a Small Container
Your cactus is ready to move to a bigger home when it reaches the size of a large marble. It’s never a good thing to wait to rehouse your cactus as it requires nutrients in order to grow and survive, just like any living thing. If you keep it in a container that is too small you are limiting the number of nutrients it has access to. That’s going to impede its growth potential, if not kill it.
Keep in mind that you’ll have to rehouse your cactus several times across its lifespan.
Much like people can get exhausted when moving and not feel up to anything, so too can a cactus. They should be given plenty of time to recuperate after being placed in a new home. Leave them out of the sight of direct sunlight for a few days to let them adjust. They have to put down new roots to get stuck into their new home. After a few days, you can start putting them back in the sun. Leave them in the sun for a little while each day, slowly increasing how long they spend in the sun.
The only way to underwater a cactus would be to literally never water it. They don’t need much water at all. You could potentially leave them for up to a month without water depending on their species.
With that said, it’s more than possible to overwater them. Overwatering cacti is a serious issue that can potentially kill them. It’s also difficult to tell if you are doing it because of how slowly they grow anyway. They might even grow a little more with more water, which makes you assume that you’re watering them properly.
Things go wrong quickly though. Cactus roots can’t deal with having a lot of water. It causes them to rot and die. The cactus can look like things are going well, but the reality is that it’s slowly but surely dying.
A cactus can survive with a few dead roots, but the more there is the greater the chance your cactus won’t survive. You might start to notice the color of the cactus changes as it starts to die. It could also become relatively mushy when felt. Once it reaches that point there’s no way to save it.
The more experience you have with raising cacti, the more you understand it’s probably a bad thing for them to start growing fast.
- Keeping them Covered up Too Long
It’s a good idea to keep cactus seedlings covered during their early germination and growth phases. It improves humidity and keeps them warm, which boosts their chances of successful germination.
With that said, you should always remove the cover when appropriate, particularly for newly growing cacti. Seedlings need some ventilation as well. Without that ventilation, they won’t be able to grow and they may die.
Top Tips to Boost Cacti Growth
If you haven’t made any care mistakes and feel that your cactus is not showing any significant signs of growth then there are some things you can do to boost cacti growth. Here are some tips on how to do it;
- Ensure that your cactus is being kept in a container that has more space than it actually needs. This ensures that the cactus has room to grow and can grow just fine. Having a larger container also reduces the need for repotting, which is going to put less stress on your cactus. Your cactus will slowly but surely grow if you keep it in a good home.
- Keep the cactus in a well-draining mixture. They thrive best when kept in a mixture of potting soil, perlite, and coarse sand. This mixture also reduces the potential for overwatering, which is one of the worst things that can happen to a cactus. We mentioned earlier that too much moisture kills their roots.
- Cacti grow best in sunny environments. You should keep yours in a bright area where they can get lots of light. Also, make sure that you rotate the cactus every week so that the entire plant absorbs some much-needed light.
- Keep the temperature at the right level for cacti to survive. Indoor cacti are at their best between 65 and 80 Fahrenheit. You’ll have to be extra careful about too much heat or direct sunlight if you keep your cacti by a south-facing window. Outdoor cacti can survive at wintertime temperatures between 45 and 55 Fahrenheit. This threshold goes up to between 65 and 85 degrees when the summer hits.
- Keep your cactus fed with a succulent fertilizer during the spring and summer. It should be a low-nitrogen liquid fertilizer.
By following these tips, you can make sure that the growth of your cactus is kept on track.
Don’t be worried if your cactus is taking a while to grow. It really does take that long. Avoid overwatering and overstressing them and they’ll grow just fine at their own pace. You will now have a much idea of what to expect when growing these iconic and magnificent plants. Growing your own cacti can be one of the most rewarding experiences, and we highly recommend it for all plant enthusiasts. It can take some patience and dedication, however, the end result makes it well worth it.