How Long Do Cacti Live?
Cacti belong to the Cactaceae family and come in over a thousand species. Each of them might have varying lifespans depending on their environment and structures.
To find out about how long cacti do live and what makes them live for this long, you can go through the following sections.
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How Long Can a Cactus Plant Live?
How long do cacti live, really? Their lifespan can range from 10 to 200 years, making them some of the longest-living plants.
It is not possible to accurately tell the lifespan of a cactus plant due to the fact that there are lots of species that belong to this family, each of which has different characteristics and lifespans.
However, you should note that cacti that can grow in their ideal conditions outdoors tend to live much longer than indoor cacti. This is because the conditions are much more restricted indoors.
To date, the longest living cactus is believed to be the saguaro (Carnegiea gigantea). This cactus can live up to 150-200 years in their natural habitats.
Why Do Cacti Live So Long?
Cacti have a relatively longer lifespan as compared to other plants due to reasons that you can go through below.
Shallow Roots
Cacti tend to live for a long time because they have shallow roots that can quickly absorb water from the soil. The roots are also dispersed well in the soil, allowing them to cover a large enough area.
In this sense, whenever it rains or whenever you water the cactus, the roots can rapidly take in as much water as they require, even if the water level is not that high.
The roots of cacti also tend to have a good concentration of salts, which can enable this absorption even more. Some species might also have fleshy roots that can help them store water.
Read also:
Understanding Cactus Root Systems: 4 Types of Cactus Roots
Fleshy Stems
For a large number of cacti species, their stems are the main component that retains and stores water for a long time, causing a large part of their structure to be filled with water.
This water can last in the stems for much longer than what other plants are able to retain. Thus, even if the cacti receive a small amount of water, they will absorb as much of it as possible so that their stems can store it.
The exact shape and size of the stems can vary from species to species, but the fleshiness is pretty common. Thus, all the water that the cacti need to survive is present in their stems, making them rely less on frequent rainfall or watering.
Read also:
6 Cactus Adaptations in the Desert
Low Water Loss
Due to the shape of the stems of the cacti, the potential for water loss is also quite low. Since the stems are usually in the shape of a cylinder, there are fewer chances of the water evaporating into the atmosphere because the surface area is not that high.
In comparison, the capacity of these stems is much higher, allowing the stems to store the water for a long time. Even if the heat levels are high, there will be a high amount of water retention, allowing the cacti to survive for a long time.
To compensate for water loss as and when it occurs, the shallow roots absorb as much of it as possible whenever the water becomes available.
Metabolism
Cacti generally have a different metabolism rate as compared to other plants which allows them to live longer. In fact, while other plants absorb carbon dioxide that they then use to carry out photosynthesis, cacti make use of a system that allows them to absorb carbon dioxide at night instead of the day.
This also reduces the amount of water that is lost to the atmosphere since the nighttime temperatures are pretty low. When photosynthesis occurs during the day, the cactus plant makes use of the carbon dioxide that the plant saved throughout the night.
This system of the cacti is known as the Crassulacean acid metabolism (CAM).
Spines
Usually, when plants have thin leaves with a large surface area, the water loss tends to be quite high. However, cacti plants do not have such leaves on their structures, allowing them to retain water for a long period of time.
Instead, cacti have prickly spines throughout their bodies. Even though these spines are exposed to the sun and air, there is no water loss since spines do not usually hold water.
The spines also serve a protective function when it comes to cacti. They prevent animals from eating the plant since the spines can hurt the animals. This allows the plants to be safe from dying due to such external factors as well.
How Long Can a Cactus Live in a Desert?
In a desert, cacti plants usually have unrestricted growth conditions, allowing them to live to their fullest extent. For instance, if they have a lifespan of 50 years, then it is likely that they will live for that long since they have more space to grow.
Further, they will also be able to receive plenty of sunlight with the temperatures being suitable for their growth and survival. Cacti are also quite resilient plants and are built to survive in the extreme conditions of a desert.
This allows them to absorb and retain plenty of water for a long enough time. This makes them live much longer outdoors in a desert as compared to indoors.
How Long Do Indoor Cacti Live?
Growing cacti indoors tend to restrict their lifespan to around ten years, sometimes even less or more. How long they live will not only depend on their species but also on the care conditions you provide.
You can find out more about these factors below.
Watering
The amount of water that you should provide to an indoor cactus plant depends on the species as well as the temperature and humidity conditions. At all costs, you should avoid overwatering a cactus since this can lead to root rot.
Besides, the stems will store the water each time, so you do not need to water it too frequently.
As a rule, however, you should water the cactus whenever the soil becomes completely dry while minimizing watering during the dormancy period.
Light and Temperature
Once again, how long an indoor cactus will live depends on the light and temperature conditions. While cacti are used to plenty of direct sunlight and extreme temperatures, you should still try to regulate this to an extent by providing regular shade during the afternoons.
Make sure the temperature ranges between 40°F and 90°F, although some species might be able to withstand the cold much better and might even prefer it. Make it a point to check the individual species’ requirements before you cultivate the plant.
You can also check the corresponding USDA zones here. Too many fluctuations in light and temperature might reduce the lifespan of the cactus.
Fertilizing
Cacti can usually survive even if you do not feed fertilizer regularly. However, if you are growing cacti indoors, then fertilizing the plant once or twice during the growing season can allow it to absorb the required nutrients from the soil so that it can live longer.
Make sure that you always dilute the fertilizer for cactus and use a balanced one, otherwise its strength will end up reducing the lifespan of your indoor cactus.
Soil
As long as you provide well-draining, loose and coarse soil for your indoor cacti, you can expect the plant to survive for a long enough time under the right conditions.
Since the roots of cacti are quite shallow, they can quickly absorb the water from the soil. Thus, by draining out the rest of the water, you can prevent the roots from rotting.
You can use a regular cactus potting mix from the store and add some sand, pumice, clay or perlite to it. You can also increase the organic content to improve the lifespan, although make sure you check the requirements of the species you are growing.
You should also use a pot with a drainage hole to ensure that the water runs out properly.
Read more here:
What Kind of Soil do Cacti Need?
Pests and Diseases
Another factor that can affect the lifespan of indoor cacti is the presence of pests and diseases. Pests such as mealybugs, thrips, flies, mites and scales can affect the health of the cactus, causing its lifespan to reduce significantly.
Various kinds of bacteria and fungi might also come into contact with the cactus, causing it to wither and die. Make sure you keep an eye on your cactus so that you can use pesticides or natural oils to get rid of them.
In case the pesticides do not work, then it might be difficult to revive the cactus. You should also keep your pets away from the cacti.
How Long Do Cacti Live without Water?
Cacti can last anywhere up to two years without water. However, this depends on the species of the cactus, since some might only be able to survive a couple of weeks without it.
If the cacti are outdoors, then this can increase their chances of survival without water. If indoors, you should ensure that you water the cacti once the soil dries out.