Chamaecereus sylvestrii
The peanut cactus, Chamaecereus sylvestrii (syn. Echinopsis chamaecereus and Lobivia sylvestrii), is a low-profile, mat-forming South American cactus with lily-like, fragrant, red-hued blossoms.
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It is suitable for outdoor cultivation in USDA Hardiness Zones 10 to 11 and makes an attractive, easy-care houseplant.
C. sylvestrii has fleshy, finger-like stems covered in vertical columns of short spines.
They are small and peanut-like when immature but grow longer, sprawling and winding as they age. Mature heights are three to four inches with a spread of 12 to 24 inches.
Peanut cactus is native to mountainous Argentinian regions.
Quick Look
Common name(s): Peanut cactus
Plant type: Cactus
Hardiness (USDA Zone): 10-11 (outdoors)
Native to: South America
Bloom time / season: Spring, summer
Exposure: Full sun, bright indirect light
Soil type: Sandy loam, succulent potting soil
Soil pH: 6.0-7.0, slightly acidic to neutral
Soil Drainage: Well-draining
Mature size: 12-24 inches wide x 3-4 inches tall
Best uses: Beds, containers, ground cover, houseplant, window box, xeriscape
Taxonomy
Order: Caryophyllales
Family: Cactaceae
Genus: Chamaecereus
Species: Sylvestrii
It has undergone several reclassifications since Italian-Argentinian botanist Carlo Luigi Spegazzini first identified it as Cereus silvestrii at the beginning of the 20th century.
In addition to the main species, there are two naturally occurring variations, C. sylvestrii f. cristata and C. sylvestrii var. giganteus, the latter with crested stems resembling wavy, flattened cockscomb flowers (Celosia spp.).
Read on to learn how to grow peanut cactus outdoors and indoors.
How to Grow Peanut Cactus
By cactus standards, C. sylvestrii is one of the faster growers, adding a few inches a year.
It’s beneficial to transplant seedlings, divisions, or nursery stock in early spring when growth is active, rather than during dormancy.
Light
Full sun is best for blooming, but plants also tolerate part shade, especially in hot climates.
Houseplants thrive in bright, indirect sunlight, about three feet from a south- or east-facing window.
Temperature
The ideal temperature range for growing peanut cactus is 50 to 80°F with low humidity.
Cool temperatures during dormancy and cool nights at the beginning of the growing season trigger late spring to early summer blooming.
Soil
If growing in the garden, loose, sandy loam with a pH of 6.0 to 7.0 is ideal.
Such non-compacting soil allows for healthy root development, and sharp drainage inhibits rotting.
Indoor gardeners should choose a substrate that contains about 50 percent organic matter and 50 percent gritty inorganic matter.
You can make your own succulent and cactus soil or buy a commercial product like Hoffman Organic Cactus and Succulent Soil Mix.
Hoffman Organic Soil Mix
This potting mix contains compost, limestone to regulate pH, peat moss, and sand for a loose, gritty, well-draining mix, ideal for cacti and succulents.
Hoffman Organic Cactus and Succulent Soil Mix is available from Hoffman via Amazon.
Watering
Cacti have shallow roots, so provide water when the top few inches of soil are dry.
In-ground cacti may need supplemental water once a month, depending upon rainfall and temperature.
If the top two to three inches of soil are dusty and the temperature soars, soak the ground around the plants, aiming the hose at the soil and not the stems.
For potted specimens, use the “soak and dry” method, letting a container dry completely before drenching the soil. Use a moisture meter to guide you.
Once established, C. sylvestrii are drought-tolerant.
Reduce watering in the fall and winter, lightly moistening the soil every month. In early spring, resume the dry and soak method.
Fertilizing
Peanut cacti don’t need fertilizer to survive, but many growers apply it once or twice during the growing season to encourage blooming.
Avoid overfertilizing, as it may burn tender roots.
For in-ground specimens, fertilize in the spring when the first new growth appears and again about eight weeks later.
Use a balanced granular, water-soluble product and water immediately after application. A product with a nitrogen (N), phosphorus (P), potassium (K) ratio of 4-10-10 is sufficient.
Lilly Miller Bulb and Bloom Food is a slow-release product that contains bone meal for strong roots and has an NPK ratio of 4-10-10.
Lilly Miller Bulb and Bloom Food
The low nitrogen and higher phosphorus and potassium promote flowering.
Lilly Miller Bulb and Bloom Food is available via Amazon.
For potted specimens indoors and out, use liquid houseplant food diluted to half-strength in early spring and apply again eight weeks later.
Schultz Cactus Plus supplies essential nutrients to succulent species. It has an NPK ratio of 2-7-7.
Schultz Liquid Plant Food
This product is available via Amazon.
Repotting
Repot container-grown plants every two to three years to replenish the growing media.
Go up a pot size if the roots start to protrude through the drainage hole.
Where to Buy
You are more likely to find peanut cactus seeds in a mix than packaged individually.
Gardeners in Zones 10 and 11 may find plants in stock at local nurseries, and growers outside this region can source bare roots online.
Note that they are often sold under the previous botanical name, Echinopsis chamaecereus.
Peanut Cactus
Three- to five-inch bare root starter plants are available from Crazy H Cactus via Amazon.
Upon receipt, place starter plants in individual three-inch pots filled with well-draining potting mix. Water until it drips from the drainage holes. Don’t water again until the pots dry out.
New growth signifies the specimen is ready to transplant to terra cotta pots or the garden as discussed in the propagation and growing sections above.
Peanut Cactus Propagation
You can start your own peanut cactus from seed, offsets, or purchase a potted plant from the nursery.
Let’s talk about each.
From Seed
Cacti started from seed are the slowest to mature. Some take more than a year to display recognizable species traits.
Because potted plants are readily available and it’s easy to divide offset pups, starting from seed is the least desirable propagation method.
However, it can be fascinating to compare propagation methods and cultivate patience in the process if you are gardening with children.
- To grow a peanut cactus from seed, you’ll need to source seeds from a reputable purveyor.
- Purchase or make your own potting mix.
- Fill a three-inch diameter plastic pot three-quarters full of media. Don’t use the biodegradable pots, as your seedlings will spend many months in these starter pots and they may begin to break down.
- Moisten the soil.
- Surface sow three seeds an inch apart in each starter pot.
- Place a heat mat under the pots and set it between 70 and 80°F.
- Put the mat and containers in bright, indirect sunlight.
- Keep the soil moist, but don’t oversaturate it.
- When seedlings emerge, select the most robust and thin them to one per pot.
When the finger-like stems fill the soil surface area and/or roots protrude from the bottom of the container, transplant them to individual four- to six-inch vessels or garden soil, as discussed below in the transplanting section.
Dividing Offsets
Dividing peanut cactus is easy. If you have a plant with multiple stems, you can separate one or more of these to create new specimens.
- Grasp a young peanut-like offset that has grown up beside a trailing parent stem.
- Twist it slightly to disconnect it from the main plant.
- Set the offset on a paper towel out of direct sunlight for about three days to form a thin callus over the “wound.”
- Fill a three-inch plastic pot three-quarters full of appropriate potting mix.
- Bury the stem slightly in soil up to the second set of spines – just enough to support it so it doesn’t flop over. Roots can grow from the callused base and the areoles.
- Lightly moisten the surface of the media and maintain even moisture as roots form. Don’t let the potting medium become waterlogged as this can cause rotting.
Signs of new stem growth signify a successful division transplant.
Transplanting
Whether you go to a garden center and purchase a potted plant or receive a bare-root specimen by mail, you’ll want to transplant it to the garden or a permanent container as soon as possible.
The same instructions apply to seedlings that outgrow their starter pots and offsets that have rooted.
- Water the plant the day before transplanting unless the soil is already moist.
- Prepare the garden soil to a depth of about four inches until it is crumbly and free of debris such as rocks.
- Set the contents of the nursery pot in the ground so the plant sits at the same depth as it was in its original container. Set bare rootstock deep enough to bury the roots and hold the plant upright.
To transplant into a container, select one made from porous ceramic, like terra cotta, for optimal airflow and to allow for excess moisture evaporation.
The size should be about two inches wider than the plant and two inches deeper than the roots. Avoid using a large container that may cause the excess soil to stay wet too long and promote rotting.
Make sure that the container has adequate drainage holes.
Remove the peanut cactus from its nursery pot and set it into the new container at the same depth as it was previously. Backfill with potting mix.
Tamp the soil and do not water or fertilize at this time.
Space plants 12 to 24 inches apart to accommodate mature dimensions without overcrowding. Ample airflow aids in inhibiting pests and pathogens.
Now, let’s consider the cultural requirements for in-ground and potted specimens.
Managing Pests and Disease
While this species is not particularly prone to problems with pests or disease, there are some to be familiar with.
Houseplants are more vulnerable to infestation than outdoor specimens because there are no natural predators indoors and pots are more likely to become oversaturated than ground soil.
Healthy plants are least vulnerable to pests and disease. Provide adequate sunlight and avoid moisture stress from over- or underwatering.
Insects
Pests that may feed on these plants include:
These sapsuckers extract juices, leaving flora desiccated and disfigured.
See our guide to controlling 11 cactus pests for management details.
Disease
The most likely disease to afflict your peanut cactus is rotting from Fusarium and/or Neocosmospora pathogens that proliferate in oversaturated conditions.
Telltale signs are soft stems and collapsed, malodorous, slimy roots.
Keep organic fungicidal, insecticidal, and miticidal neem oil on hand to treat sapsucking pests and fungal pathogens.
Neem oil is derived from the fruit of the neem tree. Use it as a preventative measure or treatment application for a host of pests and diseases. Note that it has a strong garlic-like odor.
Bonide Neem Oil
Bonide® Neem Oil is available from Arbico Organics. Choose a ready-to-spray quart, ready-to-spray gallon, or pint concentrate.
With pests and disease addressed, let’s discuss the best placements for this low-profile, sprawling species.
Best Uses for Peanut Cactus
In-ground outdoor peanut cacti are well-suited to low-water xeriscape beds and borders where they provide a nectar source for bees and other beneficial pollinators in a water-wise environment.
Let them sprawl as a ground cover or insert them between the stones of a rockery.
You can display in outdoor containers, in window boxes, or hanging planters with the stems creeping downward for vertical interest.
Indoors, enjoy potted specimens in locations about three feet from south- or east-facing windows where they can bask in bright, indirect sunlight.
A Cactus with Character
With its meandering stems and bold red flowers, peanut cactus will surely be noticed in spring-to-summer landscapes or home decor.
Provide full sun or bright indirect sunlight and fertilize twice during the growing season to get the most out of this easy-care, water-wise succulent species.
Do you grow peanut cactus? Please tell us about it in the comments section below.
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