Blue Chalksticks, or Senecio mandraliscae, is a type of succulent known and loved for its unique shape and coloring. Washed with a frosty blue, this plant is easy to grow both indoors in a pot and outdoors as a beautiful groundcover. The Blue Chalksticks succulent thrives on neglect and is easy to care for, regardless of your plant care confidence!
Use this Blue Chalksticks care guide to help grow your plant into a large, eye catching specimen!
Table of contents
Succulents are the newest trend in contemporary gardening and for good reason. They are visually interesting, easy to source, and pretty low-maintenance. As popular as they are, the key to successfully keeping a succulent is to be educated on its needs, which will differ from most other houseplants.
With that said, one of the best species for beginners is the Blue Chalksticks plant. Resembling a curved, chubby stick of chalk, the Blue Chalksticks plant really stands out among its fellow succulents. Sporting a silvery blue due to a powdery, protective coating called farina, this succulent thrives in full sun.
Senecio ‘Blue Chalksticks’ is a creeping plant, identifiable by its spiky, blue-green foliage. The species is native to South Africa where it can be found in the arid, high desert. In the wild, these plants can reach a maximum height of eighteen inches. However, domestic specimens can be expected to reach an average mature height of eight to twelve inches, making them compact enough for raising in containers or small garden plots.
- Common Name: Blue Chalksticks
- Scientific Name: Senecio mandraliscae
- Mature Size: up to 18 inches tall
- Sunlight: full to partial sun
- Water: when top ⅔ of soil is dry
- Soil: well-draining, coarse, rocky soil
- Temperature: 40°F-80°F
- Propagation: stem and leaf cuttings, division
- Hardiness Zone: 9-11
- Toxicity: toxic to humans and pets
Growth Pattern and Habits
The Blue Chalksticks plant spreads by “creeping” and producing roots from its stems. The chubby, long leaves then grow up and out from these main stems. Because of this, it makes excellent groundcover for outdoor gardens in USDA planting zones 9-11. The plant is also useful for filling in empty spaces in your garden plot. If you’re not located in the appropriate planting zone, you can still raise your Blue Chalksticks indoors as a potted houseplant.
When planted outside and exposed to the natural changes of the seasons, a Blue Chalksticks plant experiences its active growth phase during fall and winter. During this time, you will note prolific growth both vertically and outwards as it spreads across your garden. In the summer, an outdoor Blue Chalksticks plant will very likely produce dainty white flowers, however you will note that the foliage growth will greatly decrease or stop.
If the temperature is kept at a consistent comfortable temperature all year round and exposed to ample light, an indoors Blue Chalksticks succulent will likely display active growth throughout the entire year. Flowers rarely bloom on Blue Chalksticks that are grown indoors.
Expert Tip – To keep your plant looking its best, you may choose to prune the flowers as they appear, along with any other dying or leggy stems. Use any healthy pruned stems to propagate your Blue Chalksticks!
You may have seen that the term Blue Chalksticks can refer to two different plants, known by their scientific names as Senecio mandraliscae and Senecio serpens. S. mandraliscae is larger and grows fast and vigorously. S. serpens is smaller (reaching a maximum height of three to five inches), more compact and has a noticeably slower growth rate than the S. mandraliscae.
While both species have frosty blue leaves, the S. serpens has a deeper hue. Luckily for us, both species have very similar needs, so this care guide applies to both versions of Blue Chalksticks!
Your Blue Chalksticks succulent should receive at least four to six hours of direct sunlight per day. If you plan to raise this plant indoors, a sunny, south-facing window would be the best place to put it. The Blue Chalksticks can tolerate shade reasonably well, but too much of it will cause it to grow slowly or result in leggy stems.
If you notice these symptoms in your plant, you can supplement natural sunlight with an additional grow light. While this will not fix the legginess, it will encourage new growth to be more compact and full!
Due to its succulent nature, Senecio ‘Blue Chalksticks’ has relatively low water needs compared to other houseplants. The easiest way to provide for its water needs is to use the “soak and dry” method. This entails adding just enough water to saturate the soil completely, then waiting until the soil dries out completely before watering again.
I prefer to bottom water all of my succulent plants, including my Blue Chalksticks. To water your Blue Chalksticks using this method, place your potted plant in a large container, such as a kitchen tupperware, or in a deep sink. Fill the container with approximately two to five inches of water depending on the number of pots you have added. Make sure the water isn’t higher than half the height of the pots.
Leave the pots in the water for ten to twenty minutes, or until the top of the soil is wet, to allow water to soak into soil via capillary action. At this time, remove all plants and let excess water drain out of the bottom hole before replacing the plant to its normal home!
Expert Tip – Drainage holes, drainage holes, drainage holes!!! These are a must when potting any succulent, including the Blue Chalksticks.
Overwatering this plant is more harmful than underwatering. Its delicate, fragile roots can become overwhelmed by soil that’s constantly wet, which increases the risk of root rot. Therefore, you should always give the soil enough time to dry out before watering again.
It’s crucial to use well-draining soil for your Blue Chalksticks. A commercial cactus or soil mix works extremely well. Alternatively, you can combine equal parts potting soil, perlite and pumice for extra drainage. It’s also pertinent to select a container with drainage holes for raising this plant.
Temperature and Humidity
The ideal temperature range for the Blue Chalksticks is 40°F-80°F. In general, this plant can tolerate extreme heat much better than extreme cold. While some specimens have been known to survive temperatures as low as 20°F, prolonged exposure to temperatures lower than 40°F will likely cause the plant to go into shock and die. On the other hand, it can tolerate temperatures well above 80°F as long as it has some shade.
Like many other succulents, the Blue Chalksticks is excellent at retaining water on its own, so it prefers drier air. In most cases, it thrives perfectly well with average household humidity and doesn’t require any additional steps for raising humidity. To keep this plant healthy and happy, aim to keep relative humidity at 40% or below.
Thanks to its compact size and slender, finger-like leaves, the blue chalksticks only needs to be fertilized once to three times a year. Use a water-soluble, liquid fertilizer low in nitrogen, which is the best fertilizer type for succulents. Make sure to dilute it to half-strength and apply it to your plant sometime during the active growing season.
Like most succulents, the Blue Chalksticks plant is easy to propagate. Blue Chalksticks propagation is so prolific that you will have a large amount of new plants in a short period of time! The best ways to propagate your Blue Chalksticks are by either stem or leaf cuttings and by division.
Propagation by Cuttings
In this section I will talk about how to grow a new Blue Chalksticks from cuttings alone! How cool is that? You can choose to use stem cuttings or individual leaves.
- To propagate with this method, simply use a pair of sterile shears to harvest stem cuttings from your mature plant. If you want to use individual leaves, gently pull the leaf at the base and twist back and forth until it separates from the stem.
- Dip the cut end of the cuttings in rooting hormone and leave it on a clean, dry surface for a couple days to callus over.
- After two days have passed, plant your cuttings cut-side down in a container prepared with well-draining soil.
- Aim to keep the soil damp until the cuttings form their own roots and begin to grow on their own. Keep in an area that receives full sun.
- Depending on the environment, it can take anywhere from one to three weeks for the cuttings to take root. To increase your chances of success, wait until the summer to propagate your blue chalksticks.
- If you so wish, transplant the newly rooted Blue Chalksticks plants into separate pots with well-draining, succulent soil.
Propagation by Division
Once the Blue Chalksticks matures and spreads, you will notice that it has a tendency to grow in clumps. You can easily propagate more Blue Chalksticks by dividing these clumps into separate, smaller plants. This is also a great way to thin out a Blue Chalksticks that’s outgrown its pot.
To accomplish this, carefully uproot the main plant and separate the clumps, gently pulling apart the attached roots. Plant each clump in its own pot. Pay special attention to the roots, which can become damaged if you pull the clumps apart too quickly. The best time to propagate via division is during the spring when the plant is just beginning to enter its active growth phase.
The Blue Chalksticks is highly susceptible to overwatering. The first symptom of an overwatered Blue Chalksticks is poor coloration or yellowing, mushy leaves. When the condition progresses, the fragile roots can become affected, resulting in root rot. To avoid this, always test the soil before watering your plant.
The Blue Chalksticks succulents are less likely to attract pests compared to other houseplants. However, it can still become vulnerable to infestation if it’s housed near an already infested plant or if the plant is in poor condition. The two pests most likely to be drawn to this plant are mealybugs and scale, both of which subsist on plant sap.
You can tell if your plant has pests if you see unexplained, coffee-like residue on the leaves, which are insect droppings. An infested plant will also look wilted, pale, or in otherwise poor health, even if your husbandry is up to par. If you believe your plant is infested, pick off any visible insects and wipe the surface of your plant with some alcohol until its condition improves.
As a preventative measure, you can apply a solution of neem oil once a month as a safe and chemical-free treatment. Mixing in some diatomaceous earth with your soil can also discourage unwanted pests from infesting your plants. Avoid using pesticides unless the infestation is too severe for natural remedies.
The Senecio ‘Blue Chalksticks’ is known to be slightly toxic to humans or animals. It’s not considered to be an edible plant and has an unpalatable taste. Like most succulents, the leaves have a tough and thick skin, making the plant difficult to chew and digest as well. To keep your family and pets safe, always supervise young children or animals around your houseplants.
I hope this care got you as excited as I am about Blue Chalksticks! This is a fabulous succulent that loves full sun and can tolerate long periods of neglect. While this is a great succulent choice for anyone who loves houseplants, the Blue Chalksticks is especially ideal for those who tend to chronically forget to water their plants!