Echinocereus – A genus for all

Echinocereus is a genus of popular specimen plants, containing over 70 species of ribbed, cylindrical and clump-forming cacti.  A favourite contender for the specialist collector and much loved around the globe, this genus is most recognised for its tight, colourful spines and breath-taking blooms. When I was told this prickly plant family had some of the most stunning flowers of all cacti, I was compelled to take a look for myself.

echinocereus viridiflorus
Echinocereus viridiflorus

Let’s discover what makes the Echinocereus genus such a winner, and see just how easy they are to grow at home.

Native Homelands

These 70 or so species of Echinocereus are commonly native to the rocky outcrops of Mexico and South Western America, the environment here is hot and dry with cold, fresh winters and minimal rain.  Temperatures can fall well below freezing, hence many species are fully frost hardy and capable of withstanding very cold temperatures down to minus 23 degree C, minus 9.4 F., though little rain.  Other species in the genus are frost tender characters, requiring temperate home environments for successful cultivation.

Echinocereus dasyacanthus
Echinocereus dasyacanthus

Growth Forms of the Echinocereus

Plant stature of most species tend to be of upright form and cylindrical in shape.  Sizes can vary from the miniature Echinocereus pulchellus at just 2 – 5 cm in height, to the large and impressive Echinocereus triglochidiatus, the Claret Cup Cactus, reaching from 12 – 18 inches high, that’s 30 – 45 cm.

Echinocereus pulchellus
Echinocereus pulchellus

Not all species are true to form though, there are occasional surprizes within the genus, one being the Echinocereus schmollii who’s thin, branching stems question its inclusion into this special plant genus at all.

Echinocereus schmollii
Echinocereus schmollii

Why are these such a popular collector’s plant?

In cultivation, you will find that all species of Echinocereus grow smaller than in the wild.  This makes them easy to house as pot plants in a greenhouse, conservatory, or even sunny windowsill.  Natively, many species will grow into great clumps, some with several hundred stems and reaching up to a foot tall.  These however, take many years to reach this size.

Echinocereus viridiflous

Echinocereus have an array of growing forms, spine diversity and flower interest.  Along with their compact habit and over seventy individual species, this makes for an attractive collection, all housed in a relatively small amount of space.

Blooming Lovely Echinocereus

A flowering champion and one of the most popular species is the Echinocereus knippelianus.  Typically, a solitary grower and native to Mexico, the “knippelianus” is quite unusual in that its very large, pale pink flowers are often formed from the centre of the plant, as opposed to the common side placement. Its spines are borne, long and solitary, down the body of the plant, its root system readily stores water, becoming swollen and fragile to overcome the cold, dry winter months.

Echinocereus knippelianus
Echinocereus knippelianus

One of the best yellow-flowering Echinocereus is a unique-looking individual with few ribs and spines, the Echinocereus subinermis.  Its columnar form bears the largest, showiest, butter-yellow flowers of the entire genus and is one of the easiest to grow.  Offsets are one of the simplest ways to propagate from the mother plant, these willingly take root with no complications.

Echinocereus subinermis
Echinocereus subinermis

Many species have two-toned flowers with one colour towards the centre and another colour on the outer petals.  In New Mexico, U.S.A. one particular population of naturally occurring hybrids, display this colour range over one hillside from plant to plant.  These blooms can be up to 3 inches in diameter, that’s 7.6 cm, each featuring spiny floral tubes.

Echinocereus hybrids
A selection of Echinocereus hybrids

Spine formation

There is a wide range of spine formation within the genus, including some of the most fierce-looking, dramatic spines that cover the entire stem.  Most however, have moderate sized, evenly distributed spines arranged on ribs, covering the plant body.  Some species have very colourful spines in alternating patterns, some have pectinate (comb-like) spines and others can be spineless.  This characteristic is very variety dependant.

Echinocereus rigidissimus
Interesting spine formation of Echinocereus rigidissimus rubispinus

Common Characteristics of the Genus

Throughout the genus, most flowers produced will usually have numerous green stigma lobes. These stigma lobes are the receptacles which receive pollen within the flower itself.  When the pollen grain lands on receptive stigma, the process of germination can then take place.

Echinocereus stigma lobes

Less Common Characteristics

Flower buds often burst through the outer epidermis (skin) of the plant body, leaving a prominent scar after flowering has ended.

Nomenclature History and Meaning

This popular plant genus “Echinocereus”, is derived from the Ancient Greek “echinos”, meaning hedgehog and the Latin “cereus” meaning candle.

Echinocereus panamesiorum

In some countries, they are commonly known as “Hedgehog Cacti”.

My Top Species

Echinocereus nivosus

Here we have one of the few white-spined varieties which grows quite quickly, freely producing offsets as a young plant. In time, you can expect a large clump of finely spined stems, each reaching up to about 12 cm, 5 inches, in length.  When given appropriate light and warmth, your plant will eagerly produce masses of red flowers from areoles on the sides of the stems.  A stunning specimen plant with tight, white spines and lovely clustering form.

Echinocereus nivosus

 

Echinocereus pectinatus

This is one of a number of pectinate-spined varieties which has spectacular cerise-pink flowers with a fading white throat.  In this case, the term pectinate refers to the spines being arranged in regular, comb-like rows.  Also known as the “Rainbow Cactus” and an abundant species throughout the U.S.A., here we have a low-growing and solitary specimen plant with an erect, rigid habit.  Commonly found growing on rocky, gravel hillsides and semi-desert grasslands, preferring soils with an acid pH level.  Interestingly, each year’s growth is differentiated by a different coloured band of spines.

Echinocereus pectinatus v. rubispinus

 

Echinocereus russanthus

Quite an unusual specimen, the “russanthus” is one of few species with small green-brown flowers and typically difficult to distinguish.  Most specimens tend to form low clusters, all having an interesting and somewhat colourful spination, ranging from red to brown and yellow to white . Overall, this is an easy choice to raise from seed, flowering freely with strong growth and good cold-weather tolerance.  Native to areas from Texas and New Mexico, U.S.A.

Echinocereus russanthus

 

Echinocereus triglochidiatus

Also known as the “Claret Cup Hedgehog” because of its glorious deep red blooms, here we have a beautiful mounding plant with long-lasting, waxy scarlet cup-shaped flowers which bloom from April through to June, said to be the first cacti to bloom in its desert habitat.  The “triplochidiatus” is known as the most widespread species of all Echinocereus, abundant in varied habitats in the upper edge of the Mojave Desert. Its form varies from densely spined to no spines at all, with numerous stems growing together enabling greater tolerance of colder night time climates.  In cultivation you can expect a mature height of 6 to 14 inches tall, 15 – 35 cm, with a spread of 12 to 20 wide, 30 – 50 cm. This is one of the easiest of Echinocereus species to grow, flower and propagate, providing necessary light is given.

Echinocereus triglochidiatus

Planting your Echinocereus

Soil Preferences

If you choose a light, sandy growing medium with good nutritional values you can’t go far wrong.  Your Echinocereus needs a slightly richer compost than other plants in the Cacti family – this can be achieved by adding high nutrient soil improvers such as leafmold or well-rotted garden compost to your typical free-draining compost mix.

Site Preferences

All plants within the Echinocereus genus will accept a full or nearly full-sun site quite readily, which will in turn promote prolific flowering. Providing bright light from a west-facing aspect is perfect.  Plants which are grown in shaded conditions will never perform or flower as well.

Many species may be cold-tolerant, but generally all need relatively warm temperatures to thrive.

Echinocereus coccineus
Echinocereus coccineus

Temperature Preferences

Among Cacti enthusiasts, the Echinocereus genus is known for being a little easier to grow than their cousins, making them perfect for the novice home grower.  A glasshouse is essential for the serious collector, though smaller collections can be housed in a conservatory or even a sunny window ledge. The minimum temperature you decide to maintain is completely dependant on which plant species you decide to grow.  Small-growing species and tender species will need to be kept at a temperature of at least 50 degrees F, 10 degrees C.  Ideal growing temperatures range from 65 – 85 degrees F, 18 – 29 degrees C , while dormant plants do best at the minimum range.

Fruits

Echinocereus have typically hairy fruits, which are quite large in relation to the plants.  Certain species have edible fruits which have a similar taste to strawberries, so I am told.  Just to be safe, please check your species before you taste the fruits!

Echinocereus fruits

Caring for your Echinocereus

Watering

Ensuring you have planted your Echinocereus in a well-draining cacti soil mix, I would recommend watering your plant once every couple of weeks through the summer growing season.  It is best to water well, letting the excess drain away and allowing the compost to dry out a touch before watering again.  Throughout the winter time, your plant needs to be kept pretty dry and allowed to rest.  Only water once a month in the winter months.

Echinocereus x roetteri
Echinocereus x roetteri

Feeding

Throughout the summer growing period, feed your Echinocereus every couple of weeks with a well-diluted Cacti fertilizer from April to September.  When in dormancy, you will not need to feed your plant in the winter months.

Propagation

The easiest way to propagate from the Echinocereus genus is by way of offsets.  This is a very successful way of growing your plant collection and I have added a quick “How To” below:

  • Remove the plantlet and leave it to dry out
  • When a callous form over the cut, carefully prepare your small off-set pots, filling them with a suitable compost mix
  • Gently plant your cuttings in the prepared pots and moisten
  • Keep your cuttings warm and only water to barely moisten the compost
  • Your cuttings will root and create new growth
Echinocereus scopilorum
Echinocereus scopulorum

You can also produce new plants from seed in a shallow and free-draining seed compost.  Remember to keep your seeds moistened and warm until germination takes place.  This should be between 2 – 3 weeks.

Plant Problems

Pests

When it comes to plant pests, the sap-sucking mealy bugs and aphids should be the only culprits you need to watch out for.  If you do find an infestation, place the plant in isolation and set about treating your plant.

Organic pest spray

Mealy bugs and aphids can be eradicated by spraying your plant with an organic plant pest spray, spraying with neem oil, or choosing an effective insecticide available from your local garden centre.   You may need to give multiple applications to remove the pests completely.

Diseases

Root rot is common among succulents and cacti but totally avoidable. Echinocereus have weak root systems which are prone to root rot when over-watered.  It is best to allow your planting soil to adequately dry out before re-watering your plants.

Echinocereus spines
All images courtesy of Pinterest

Now that we’ve seen what the Echinocereus genus has to offer the Cacti enthusiast, why not have a look for yourself and start your own Echinocereus collection?