Seeing a cactus bloom is a highly rewarding experience only a few get to see, as these flowers are usually short-lived and only appear if conditions are just right. If your cactus has never produced blooms, how can you encourage it?
You can encourage your cactus to flower by keeping it in the right humidity, temperature, and lighting conditions, properly watering it, and using well-draining soil and pots. You should also double-check for root binding, diseases, and pests and treat them accordingly.
In this article, I’ll provide 12 useful tips for encouraging your cactus to flower. Let’s dive right in!
1. Determine if Your Cactus Has Matured
Before trying to encourage your cactus to flower, one of the first things you should do is to determine if your cactus has fully matured.
This is very important because some cacti species only blossom once they are completely mature. Every cactus species matures at different rates, with some maturing after a year or two. Other species, like the saguaro cactus, can take up to 50 years to reach maturity.
I recommend identifying the exact species of your cactus and trying to determine how long it’s been alive, so you can predict when it might be ready to bloom. If it’s not mature, you can’t expect it to bloom any time soon, and you’ll need to exercise patience.
If you really want to experience the pleasure of your cactus blooming, you should consider only buying cacti that already have flowers, so you can be sure the cactus has reached full maturity. Remember this the next time you visit your local plant or succulent nursery.
Once mature, various cacti species can also bloom at different frequencies. Here are some popular cactus species grown at home that bloom annually under the right conditions:
- Pincushion cactus (Mammillaria spp.)
- Spider cactus (Gymnocalycium spp.)
- Ball cactus (Parodia spp.)
2. Encourage Blooms in Spring or Summer
The next thing you should remember is that a cactus will only bloom if it’s actively growing. A cactus’s active growing season is in the spring and summer when temperatures and light levels are higher.
This growing season is the best time of year to encourage cactus blooms. While some regions stay warm throughout winter, most cacti will not bloom during this time to preserve energy for creating flower buds. If you want to put in some extra effort to get your cactus to flower, make sure you do this during the hotter months of the year.
3. Keep Your Cactus at the Right Humidity
The next tip for encouraging your cactus to bloom is to provide it with the correct humidity conditions.
Humidity refers to the amount of water in the air and is vital to plant growth. Each plant has different requirements, depending on where it comes from. For example, tropical plants require a higher humidity of about 60% or more because they originate from humid climates.
Desert cacti usually require lower humidity levels and will have better chances of blooming indoors if the humidity stays between 30 and 40%. On the other hand, 60% is the best overall humidity level for most epiphytic cacti.
Providing your cactus with suitable humidity conditions is key to creating an environment that encourages flower growth. A cactus will only produce flowers when all of its needs are met, and humidity is one of the most essential needs.
However, one thing to note is that you shouldn’t let the humidity in your home get too high or too low. If it gets too high, your plants will have difficulty making the water in their soil evaporate or absorbing the nutrients in that soil, which can lead to rot.
Conversely, if the humidity levels get too low, this can cause symptoms similar to underwatering because there isn’t enough water in the air for the plant to absorb.
So, it’s important to ensure that the humidity levels are just right because too much or too little is harmful to your cactus.
How To Control Indoor Humidity
Luckily, controlling indoor humidity is a relatively simple process, thanks to modern technology.
One of the first things you must do is ensure you have a hygrometer. A hygrometer is a device that allows you to check the moisture level in your home’s air. Thankfully, these are pretty easy to acquire and are usually pretty cheap.
Once you’re able to check the humidity in the air, you might need to make some adjustments, depending on whether your home’s humidity is high or low.
If you need to raise the humidity, you can use a humidifier to increase moisture levels. Here are some other things you can do to raise your home’s humidity without investing in a humidifier:
- Boil water in a pot
- Acquire more houseplants
- Take hot showers and leave the bathroom door open afterward
A dehumidifier will do the trick if you need to lower the humidity. However, like a humidifier, these can get pretty pricey and take up quite a bit of space.
If you want to lower the moisture levels in your home without investing in a dehumidifier, here are some tips:
- Use fans
- Take cold showers
- Run your AC
- Place litter boxes around your house to absorb the excess moisture in the air
By adjusting the humidity to meet the needs of your plants, you can promote a healthy environment for your cactus and encourage it to bloom.
4. Keep the Temperature Suitable for Cacti
The next thing you need to do to encourage your cactus to bloom is to ensure the temperature is just right.
Like humidity requirements, a plant’s temperature requirements must be met to promote good health and new growth.
Since most cacti are native to the desert, they need temperatures similar to this region. The best temperature range to keep your cactus in is 70-90 °F (21-32 °C).
If the temperature is too hot or too cold, it can have negative effects on your cactus’s blooming, so it’s crucial to ensure the temperature is perfect.
However, one thing to note is that the temperature at which your cactus is kept during winter is just as critical as the temperature in the spring and summer.
For a cactus to produce flowers, it needs to go through a dormant or resting period where it is not growing and can conserve energy to spend on producing flower buds.
However, if you keep your cactus at the same temperature year-round, it won’t go through its dormancy period. These are unsuitable conditions for a cactus and will decrease the likelihood of flowers.
Try to keep your cactus at lower temperatures to encourage this dormant period during the winter. The coldest temperature it can withstand is about 55 °F (13 °C).
To ensure your cactus’s temperature requirements are met, it’s worth investing in a thermometer. While some hygrometers have a combined thermometer setting, you can purchase a more advanced thermometer to give you better temperature-specific analytics.
Once you get a good sense of your space’s temperature, you can adjust it accordingly. Using space heaters and grow lights is a great way to increase the heat levels for your cactus.
By adjusting the temperature to make things comfortable for your cactus, you can encourage the growth of flowers and enjoy beautiful blooms.
5. Use Well-Draining Soil
Another vital part of curating ideal conditions for your cactus is to make sure you’re using well-draining soil.
A cactus cannot bloom if it’s not healthy, and without proper drainage, your plant will face several adverse effects that can make it difficult to grow flowers.
Because cacti are desert natives, they require rocky and well-draining soil that doesn’t retain too much water. Otherwise, their roots can rot or even drown.
Luckily, there are many cactus-specific soil options on the market. You can either make your own mix by combining one part pumice or perlite with one part dirt or purchase a store-bought mix explicitly designed for cacti.
By using well-draining soil, you can keep your cactus healthy and encourage it to grow flowers.
6. Check for Aerial Roots and Root Binding
Another thing you should do to encourage your cactus to bloom is to check for aerial roots and root binding.
When a cactus has overgrown its pot, its roots no longer have the space to grow properly, so they begin to grow in circles around the container. This can cause your cactus to become rootbound, which can result in many negative effects and lower the overall health of your plant. It will also decrease the likelihood of flower growth.
Sometimes, when a cactus is root-bound, it can grow aerial roots to try and absorb nutrients, water, and carbon dioxide from the air, as there is no more space for it to do so below the soil.
If you want your cactus to grow flowers, you should check for aerial roots and root binding, as these can be signs that your plant needs to be repotted. While aerial roots themselves are not really a problem, they can serve as an indicator that some care adjustments need to be made to keep the cactus healthy.
For more information, check out my article discussing whether cactuses like being root-bound: Do Cactuses Like to Be Root Bound? What You Need to Know
7. Treat Your Cactus for Pests and Diseases
Treating your cactus for pests and diseases is an additional way to promote good cactus health and encourage the growth of flowers.
As mentioned before, a cactus will only grow if it’s comfortable and the conditions are right. If a cactus is infested with pests or infected with a disease, it is not in good health and needs to be treated before you can expect it to grow flowers.
My favorite DIY remedy for treating plant pests is cinnamon. This is a super cheap, accessible, safe, and natural way to prevent and remove bug infestations. You can either sprinkle it directly onto the soil or mix it in with the dirt. It also has a lovely aroma.
Another great way to do this is to combine one part apple cider vinegar with one part water and spray the solution directly onto your cactus (just enough to remove the infestation). This will also help remove some fungal infections.
You can always use store-bought solutions if you don’t have cinnamon or apple cider vinegar on hand. Mixtures that contain neem oil are usually very effective.
By addressing issues involving pests and disease, you can promote good cactus health and create an environment that encourages flower blooms.
8. Use Plant Food or Fertilizer for Nutrients
Another fantastic way to boost the health of your cactus and promote flower growth is to use plant food or fertilizer to provide it with extra nutrients.
Plant food is an effective way to give your plant an extra nutrition boost during spring and summer when it’s using a lot of its energy, food, and water reserves to grow. This can also be an efficient method for encouraging cactus flowers to bloom.
Opt for a cacti fertilizer that’s high in phosphorus. A granular fertilizer with an NPK ratio of 5-10-10 is excellent for encouraging cactus blooms. You can apply it once in spring and again in early summer.
9. Place Your Cactus in a South-Facing Window
Your cactus’s light conditions can also affect whether or not it will produce flowers.
We all know that plants use photosynthesis to produce food from light. When a plant doesn’t have access to enough light, it can be difficult for it to create enough food.
This is especially important for cacti, as most of these plants are used to living in the desert and require desert-like conditions to thrive. If your cactus doesn’t have access to enough light, it’s not likely to grow flowers.
The best location for cacti is in a south-facing window. This area receives plenty of sunlight throughout the day and provides your cactus with optimal light conditions that can encourage it to flower.
10. Use Artificial Grow Lights for Poorly-Lit Spaces
If you don’t have a south-facing window to place your cactus in, don’t worry. There are other ways to address light-related issues.
If you cannot place your cactus in a south-facing location, you could always invest in some grow lights. Using artificial grow lights is an easy solution to light deficiency problems and can help create an environment for your cactus that will encourage flower growth.
Opt for grow lights with a good balance of red and blue light with an intensity of 4000 foot candles. The red light is necessary to promote flowering. Place the light at least 12 inches (30 cm) above the cactus and leave it on for at least 10-14 hours a day from spring to late summer.
11. Stick to a Suitable Cactus Watering Routine
Another crucial part of encouraging your cactus to flower is sticking to a proper watering routine.
While this step might seem simple, it’s actually one of the most important parts of cactus care—and the trickiest to get right.
A cactus is famed for its ability to survive through harsh, drought-like conditions common in desert regions. However, it still needs to be watered regularly. You should water your cactus after the soil dries between waterings.
A good rule of thumb is to water your cactus once every 2-4 weeks:
- Once every 10-14 days in the warmer months
- Once every 4 to 6 weeks in the colder months
However, your region’s climate and your home’s light, temperature, and humidity conditions can influence the frequency.
The best way to ensure your cactus is properly hydrated is to check the soil moisture before watering. Check how long it takes for the top half of the pot to dry out. Only water your plant when the soil is dry enough.
Although underwatering can be detrimental to the health of your cactus, so can overwatering. Watering your cactus too often can lead to rot and other issues you want to avoid.
By sticking to a proper cactus watering routine, you can keep it healthy enough to inspire it to bloom.
12. Use Pots With Drainage Holes
The last tip on my list for encouraging a cactus to flower is to use pots with drainage holes.
As previously mentioned, water drainage is a vital part of cactus care. Without well-draining soil, your cactus can rot. However, in addition to drainage-supporting soil, your cactus’s container should have holes for water to escape.
There are many decorative pots on the market that are fun and aesthetically pleasing, but these don’t always have proper drainage holes and are usually meant to serve as an outer pot, also known as a cache pot
Unless you’re using a terracotta pot with a drainage hole and tray, you should keep your cactus in a plastic container to keep inside a cache pot if you’re going to use a decorative one without holes. Ensure that the excess water has drained out completely before returning the plastic pot to the cache pot.
By ensuring that your cactus is placed in a well-draining container, you can keep it healthy and encourage it to bloom.
Cactus flowers are usually short-lived, but that doesn’t mean they aren’t rewarding to experience. If you want to encourage your cactus to produce beautiful blooms, try determining if your cactus has fully matured, waiting until spring or summer, keeping conditions just right, giving your plant a boost with fertilizer, and treating for pests and diseases.
By following these tips, you can help encourage your own cactus to flourish and produce rewarding blooms this growing season.