While Fairy castle cactus doesn’t require any changes in temperature to enter different growing phases, it is important to stay consistent. Wild temperature fluctuations can slow down its growth regardless of its current phase, so it's always better to keep them in a controlled environment. That optimal temperature range of 77°F and 90°F (25-32℃) is vital to maintain, especially staying above the lower limit. Going above 90°F isn’t ideal, but as tropical plant it won’t suffer too much. On the other hand, going below 77°F (25℃) (and especially 41°F/5℃) will begin to directly damage this heat-loving plant species.

Fairy castle cactus does not need different temperatures for different growing seasons. The most important step in seasonal care is to keep the environment within the optimal temperature range. That's why it's always best to keep this plant indoors. That way, you can control the temperature no matter what the climate is like outside.

Light is also important for tropical species, with all of these plants preferring a partial side level of sun exposure. This means any light they receive needs to be dappled or filtered, with bright but indirect light being the best option when growing your plants indoors. Too much direct sunlight can negatively affect your plant’s leaves, reducing its growth potential.

Tip #1: Don’t Leave Your Plant Near Windows in Colder Months
If you want to make sure your plant isn’t exposed to colder temperatures, you may want to keep them away from windows. In colder months like late fall and winter, even the smallest draft can leak cold air into your home through cracks in your windows. While this air usually dissipates and warms up as it travels throughout your home, any plants placed in close proximity to the window will be affected. Move your tropical plants into an area where they will still get bright but indirect light, while making sure they won’t be affected by potential drafts.

Tip #2: If You Find Dry Patches, Your Plant May Be Getting Too Much Sunlight or Heat
You may notice the leaves become white or even scorched on a sunny day. These discolorations and unusual markings usually indicate that a plant is getting too much heat or sunlight, and it may be dehydrated. Excess light and heat will dry out the soil, stopping plants from getting the moisture they need to support their cellular structure. It also slows down or stops the process of photosynthesis, further hindering growth. If ignored for too long, these dry spots can spread and eventually result in the death of your plants.

Tip #3: Avoid Frost at All Costs
Colder temperatures and frost can damage your plants by causing ice crystals or disrupt normal physiological activity. This makes it nearly impossible for water to move freely throughout plant tissue, creating a deficit of moisture in their stems and leaves. You can tell a plant has been damaged by frost if it begins to suffer from hydrosis (it will appear as though it's soaked with water.) If the problem persists, your plants may begin shriveling and turning a dark brown or black hue. After that, the plant will almost certainly die.

The best way to maintain the right temperature range for Fairy castle cactus is by keeping an eye on both the climate and humidity. You’ll want to try to keep each species in a room where you have access to climate control, keeping the heat in the temperature range best mimics its natural habitat. The humidity levels will also have a direct effect on temperature, so it's important to monitor these as well. You can artificially raise the humidity of your growing space by using a humidifier or lightly misting the leaves with water.

If you intend to grow this species outside, you may find it difficult to maintain the right balance of temperature and humidity. If temperatures begin to drop or the air becomes too dry, your best option is to find room within your home and move your plant inside. An indoor growing space will allow you to control the climate more closely, helping your plant reach its full potential.

For this tropical plant to thrive, you’ll want to keep them between 75°F and 90°F (25-30°C). Each species can handle temperatures outside of this range, but keeping it within several degrees of these limits will ensure they grow to their maximum potential.

As for its extreme temperature limits, any environment below 41°F (5℃) or above 104°F (40℃) will begin to hinder its growth and cause various aberrations to its leaves and stems. This is especially true with low temperatures; even a light frost can cause your tropical plants to perish. Cellular death can begin to happen at a rapid pace, with some species dying in as little as 12 to 24 hours.

Fairy castle cactus and other summer dormant plants require some care in the spring.

Tip 1: Water the plant whenever the top layer of soil begins drying out to help support its vigorous spring growth. Do not allow the soil to completely dry out and avoid getting moisture on the plant’s crown (center).

Tip 2: Apply a balanced fertilizer every two weeks until summer to encourage blooming.

Tip 3: Move container plants into the sunlight, ensuring the plant receives several hours of light a day.

Tip 4: Prune back any dead growth but do not remove green stems.

Since Fairy castle cactus and other cool weather plants are dormant in the summer, they do not require a lot of care.

Tip 1: Allow the soil the top layer of soil to dry out before watering and do not continue fertilizing.

Tip 2: Removing any spent flowers and dead leaves can encourage reblooming in the fall.

Tip 3: Move a container plant into a shady area during its summer dormancy period.

Your Fairy castle cactus will wake up during the cool fall.

Tip 1: Give your plant a good cleaning as it wakes up, pruning away dead or diseased branches and yellowing leaves, or even weak branches, in order to encourage fresh and strong growth and keep the plant looking its best.

Tip 2: This is the time to repot your plant if you choose to move its location.

Tip 3: Begin regular watering once again to keep the soil slightly moist, but not soggy.

Tip 4: Continue your regular fertilization schedule during the fall, and make sure it's receiving adequate amounts of light to support its growth.

Your cool-loving Fairy castle cactus will be at its most active during the winter.

Tip 1: Watering is essential. Make sure the soil is moist during this active growth, keeping up with a regular watering routine.

Tip 2: Your plant should receive adequate sun, but plenty of shade is also important, so make sure the plant is in a location that’s shady in the afternoon.

Tip 3: Continue your regular fertilization schedule, feeding it once or twice during this season or using a slow-release variety.

Tip 4: You may also choose to propagate or repot the plant during this time, when it’s actively growing.