In Types

Silver Arrows Cactus (Mammillaria nejapensis) Care Guide

Silver Arrows cactus
Sun ExposureFull sun to Partial sun
Water NeedsMinimal
Mature Size6-8″ tall indoors
Temperature Tolerance25°F
Propagation StyleCuttings, offsets
Dormant PeriodWinter

Basic Information about Silver Arrows Cactus (Mammillaria nejapensis)

Common Name- Silver Arrows or Royal Cross

Origins- Oaxaca, Mexico

Description- Flowering cactus in the Cactaceae family

Sun exposure– Partial shade to full sun 5-6 hours a day

Water needs– Once a week in warm months, once every two weeks in winter

Mature size– 6-8 inches

Temperature tolerance– Tolerates down to 25 °F

Propagation style– Cuttings or Offsets 

Toxicity– Non-toxic to humans and pets 

Dormant season– Winter

How do You Take Care of a Silver Arrow Cactus (Mammillaria nejapensis)

watering a succulent

Are you thinking of adding a Silver Arrows cactus to your collection but aren’t sure how to take care of it? Silver Arrows is a slow-growing cactus with a cylindrical stem that often branches into two. 

The stems are dark green and covered in sharp silvery bristles. Mammillaria nejapensis, as it is scientifically known, is not only fun to grow but also easy to care for. 

Should You Grow Your Silver Arrow Cactus Indoors or Outdoors

Silver Arrows does best when grown outdoors, but it can still thrive indoors as long as it gets all the requirements for growth. Whether grown indoors or outdoors, ensure that your Mammillaria nejapensis has enough lighting, enough water, and well-drained soil. 

Light Requirements

Silver Arrows require about 5-6 hours of sunlight a day. If you’ve placed it indoors, consider moving it around until you find the perfect spot where it can receive enough light. 

Spots near windows are best because, on sunny days, the plant receives enough light and, on humid days, there is enough air circulation. 

If grown outdoors, Mammillaria nejapensis can tolerate partial shade to direct sun. Don’t expose young plants to direct sun before acclimatizing them gradually. 

The Silver Arrows cactus loves a window to stay in

When acclimatizing, expose the plant to full sun in the morning when the sun is not too hot and provide shade in the afternoon when the sun can get too hot. 

Even for fully established plants, watch out for heat waves when the sun is extremely hot because they will sunburn your plant. 

Frost Tolerance

The Silver Arrows cactus is tolerant of frost up to temperatures of about 25 degrees Fahrenheit. If your area is prone to cold winters, consider growing your cactus in a terrarium so it’s easy to move indoors where it’s warm. 

If your cactus will be out in cold temperatures, make sure that the soil remains dry and gets enough lighting during the day. 

Soil Needs

Mammillaria nejapensis thrives in well-draining cactus soil. To increase drainage, consider adding some perlite and coarse sand in equal parts. Like any other succulent, Silver Arrows will suffer root rot if it sits in water for long periods. 

cactus soil

Watering Requirements

The Silver Arrows cactus requires little water to thrive. Ideally, you should water them once a week on hot days. During spring and fall when it’s a bit cool, watering once every two weeks should be sufficient. In winter, minimize watering to once a month, so the plant remains dormant for proper blooming. 

It’s important to note that Mammillaria nejapensis grown indoors may not need as much watering as those grown outdoors because they don’t respirate much. Before watering indoor plants, poke your fingers into the soil to ensure that the soil is dry. 

How Big do Silver Arrow Cactus Get? 

Mammillaria nejapensis will grow to about 6-8 inches tall and 4-6 inches wide. Initially, the plant grows as one round piece and later branches into two stems, forming clusters. Generally, it is a slow-growing plant. 

Does a Silver Arrows Cactus Flower? 

silver arrows cactus bloom

Yes, Silver Arrows produces white, cream, and pink blooms. Blooming happens in spring and summer after dormancy which happens in winter. Not all Silver Arrows will bloom depending on the environment and the conditions provided for growth. 

If you want to encourage blooming, reduce watering in winter and ensure that the soil has proper drainage. During spring and summer, increase watering sessions gradually to break the dormancy. 

Fertilization is also necessary during this period of active growth. A fertilizer suitable for cacti diluted in a quarter or half strength and applied every two weeks should be sufficient. 

How to Propagate the Silver Arrows Cactus (Mammillaria nejapensis)

The best way to propagate Silver Arrows is by using offsets that cluster around the mother plant’s base. Uproot the offsets, ensuring to remove as many roots as you can and taking care not to damage them. 

Place the offsets on a dry surface to allow the cut edges to form a callous. Then, dip the cut edges into a rooting hormone before planting them in a pot filled with well-drained cactus potting soil. 

Keep misting the soil whenever it gets dry, and also place the pot where it can receive enough sunlight until new roots emerge. Roots will establish in about 3-4 weeks, after which you can either place the plant outdoors or indoors near a window. 

Do not overwater your propagation or it will quickly rot

Remember not to place the young plant in direct sunlight without a shade before acclimatizing it first. The shock could kill your plant, rendering all your efforts futile, and of course, you don’t want that to happen. 

Is the Silver Arrows Cactus Toxic?

Silver Arrows cactus is considered non-toxic to pets and humans. However, the plant has some sharp spines that could puncture your skin or pets. Handle the plant using gloves or thick clothing to prevent pricks. 

Alternatively, you should grow the succulent in a terrarium so that it doesn’t pose a risk to pets and children who are often curious. Regardless of its non-toxicity, you shouldn’t ingest any parts of the plant. 


The Mammillaria nejapensis is a beautiful cactus that is easy to care for whether you’re a beginner or an experienced gardener. Provide it with enough sunlight, properly drained soils, and enough water, and your plant will thrive. 

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