Genus Reference
Cactus
Cactaceae identification and cultivation: barrel cacti, prickly pears, columnar species, epiphytes, and the rare collector forms.
The Complete Cactus Guide: Family, Cultivation & Care
A practical Cactaceae guide covering cactus anatomy, major genera, light, water, mineral soil, winter dormancy, propagation, and common problems in cultivation.
Read the guide →Species & Cultivars
All articles in this section
Cactus Rot Treatment: How to Cut, Dry & Rescue a Rotting Cactus
A practical cactus rot rescue guide covering root rot, basal rot, stem rot, when to cut, how long to callus, and when a plant is no longer salvageable.
Cactus Sunburn Recovery: Scorch Signs, Treatment & Prevention
How to recognise cactus sunburn, stop scorch from worsening, distinguish it from rot and corking, and acclimate cactus plants safely to stronger sun.
Cactus Soft Spots: Staging Rot Before It Spreads
How to stage cactus soft spots from early surface discolouration through core rot, when to cut versus monitor, and how to callus and repot a salvaged…
Cactus Corking: Normal Aging or a Warning Sign?
How to distinguish normal cactus corking and woody basal browning from rot, sunburn, and physical damage, with a diagnostic table and identification criteria.
Cactus Etiolation Fix: How to Stop Stretching and Recover Shape
How to diagnose etiolation in cactus plants, correct low light safely, decide when to cut stretched growth, and prevent weak pale cactus growth indoors.
Cactus Turning Yellow: Causes, Diagnosis & Recovery
Why cactus stems turn yellow, how to separate stress colour from rot, sunburn, nutrient problems, pests, and cold damage, and what to do next.
Cactus White Fuzzy Spots: Mealybug, Wool or Mold?
How to identify white fuzzy spots on cactus plants, separate natural wool from mealybugs and mold, treat infestations, and prevent reinfestation.
Cactus Shriveling: Drought, Root Loss, Rot & Recovery
Why cactus stems shrivel, how to tell normal drought contraction from root loss or rot, and how to rehydrate safely without over-watering.
Cactus Spider Mites: Identify Webbing, Treat & Prevent
Isolate the affected plant immediately, then inspect all other plants in the collection for fine webbing and moving dots.
Cactus Not Flowering: Age, Dormancy & the Dark Period Fix
Identify whether the plant is a desert cactus or a jungle epiphyte before adjusting care, since the flowering triggers are opposite for each group.
Cactus Turning Purple or Red: Cold Stress vs Sun Stress
Why cactus stems turn purple, red, or pink, distinguishing cold and UV anthocyanin from sunburn, drought stress, nutrient deficiency, and pathological…
Rhipsalis baccifera (Mistletoe Cactus): The Old-World Cactus
Rhipsalis baccifera, the mistletoe cactus, is the only cactus native to both the New and Old Worlds. Care notes for this trailing epiphyte with white berries.
Astrophytum myriostigma (Bishop's Cap Cactus): Profile & Care
Profile of Astrophytum myriostigma, the bishop's cap cactus: Mexican limestone habitat, five-rib form, yellow flowers, seed propagation and safe pot care.
Opuntia humifusa / compressa (Eastern Prickly Pear): Profile & Care
Profile of Opuntia humifusa, the eastern prickly pear: identification, cultivation, propagation, and the cold-hardy mat-forming Opuntia of the East.
Cereus forbesii 'Spiralis' (Spiral Cactus): Profile & Care
Cereus forbesii 'Spiralis', the Spiral Cactus, is a stable cultivar with contra-clockwise twisting ribs, blue-green columns, and reliable cutting propagation.
Selenicereus undatus (Dragon Fruit Cactus): Profile & Care
Selenicereus undatus, the dragon fruit cactus, is a climbing tropical vine cactus with three-winged stems, huge nocturnal white flowers, and edible pink fruit.
Parodia leninghausii (Lemon Ball / Yellow Tower): Profile & Care
Profile of Parodia leninghausii: south Brazilian native lemon ball with golden soft spines, mature size, flowering age, ID against P. magnifica and Notocactus.
Mammillaria hahniana (Old Lady Cactus): Identification & Care
Field guide to Mammillaria hahniana, the old lady cactus: white wool, pink flower ring, Mexican origins, and cultivation tips for beginners and collectors.
Cleistocactus strausii (Silver Torch Cactus): Profile & Care
Cleistocactus strausii, the silver torch cactus, is a slim columnar species from Bolivia and Argentina with dense white bristly spines and a silver sheen.
Cereus repandus / peruvianus (Peruvian Apple Cactus): Profile & Care
Cereus repandus, the Peruvian apple cactus, is a fast growing columnar tree cactus from South America with edible fruit and large white nocturnal flowers.
Carnegiea gigantea (Saguaro): Habitat, Cultivation Limits
Profile of Carnegiea gigantea, the saguaro of the Sonoran Desert: 12 to 18 m, 150 to 250 year lifespan, identification, cultivation limits, legal status.
Mammillaria spinosissima (Spiny Pincushion Cactus): Profile & Care
Profile of Mammillaria spinosissima, the spiny pincushion cactus: Mexican volcanic habitat, variable spines, flower crown, care and propagation notes.
Mammillaria plumosa (Feather Cactus): Profile & Care
Profile of Mammillaria plumosa, the feather cactus: Nuevo León limestone habitat, feathery white spines, winter flowers, CITES status, ethics and care.
Astrophytum ornatum (Star Cactus / Bishop's Hat): Profile & Care
Profile of Astrophytum ornatum, the largest Astrophytum: Mexican limestone habitat, tall ribbed body, curved spines, yellow flowers, and safe pot care.
Ferocactus cylindraceus (California Barrel Cactus): Profile & Care
Profile of Ferocactus cylindraceus, the California barrel cactus: native range, ID by straight centrals vs F. wislizeni hooked spines, CITES II, and care.
Opuntia ficus-indica (Indian Fig / Prickly Pear): Cultivation
Profile of Opuntia ficus-indica, the Indian fig or prickly pear: identification, cultivation, propagation, and the species behind nopales, tunas, and cochineal.
Epiphyllum oxypetalum (Queen of the Night): Profile & Care
Epiphyllum oxypetalum, the queen of the night, is an epiphytic cactus native to Central America with huge fragrant white flowers that open for one night only.
Mammillaria elongata (Lady Finger / Gold Lace Cactus): Profile & Care
Field guide to Mammillaria elongata, the gold lace cactus: golden spines, clustering stems, Mexican highland origins, and cultivation tips for beginners.
Echinocactus platyacanthus (Giant Barrel Cactus): Profile & Care
Profile of Echinocactus platyacanthus, the giant barrel cactus of central Mexico: largest barrel species, flat curved spines, very slow growth, and care notes.
Astrophytum asterias (Sand Dollar / Sea Urchin Cactus): Profile & Care
Profile of Astrophytum asterias, the sand dollar cactus: Texas and Mexican origins, endangered status, starry spineless body, summer flowers, and care.
Gymnocalycium mihanovichii (Moon / Ruby Ball Cactus): Profile & Care
Profile of Gymnocalycium mihanovichii: Paraguay and Bolivia native, wild type ID, why chlorophyll deficient Hibotan moon cactus must be grafted to survive.
Parodia magnifica (Balloon Cactus): Profile & Care
Profile of Parodia magnifica, the South Brazilian balloon cactus with 11 to 15 ribs and golden summer flowers. ID, cultivation, frost limit, and propagation.
Mammillaria zeilmanniana (Rose Pincushion): Profile & Care
Profile of Mammillaria zeilmanniana, the rose pincushion cactus: Guanajuato canyon habitat, hooked central spines, magenta flower ring and care notes.
Ferocactus wislizeni (Fishhook Barrel): Profile & Care
Profile of Ferocactus wislizeni, the fishhook barrel cactus of the SW USA: hooked central spines, southward lean, CITES II status, identification, and care.
Opuntia basilaris (Beavertail Cactus): Profile & Care
Profile of Opuntia basilaris, the beavertail cactus: identification, cultivation, propagation, and the cold-hardy magenta-flowered Mojave desert species.
Echinocactus grusonii (Golden Barrel Cactus): Profile & Care
Profile of Echinocactus grusonii, the golden barrel cactus: Mexican origins, endangered wild status, golden spines, flowering age, and practical care.
Astrophytum capricorne (Goat's Horn Cactus): Profile & Care
Profile of Astrophytum capricorne, the goat's horn cactus: Mexican gypsum habitat, twisted papery flat spines, yellow red-throated flowers, and pot care.
Rebutia minuscula (Red Crown Cactus): Profile & Care
Profile of Rebutia minuscula, the Argentine red crown cactus with lateral-basal flowers and high-elevation frost tolerance. ID, cultivation, propagation.
Opuntia microdasys (Bunny Ears Cactus): Care & Glochid Safety
Field-guide profile of Opuntia microdasys, the bunny ears cactus: identification, cultivation, propagation, and how to safely handle its barbed glochids.
Schlumbergera truncata (Christmas / Thanksgiving Cactus): Profile & Care
Schlumbergera truncata, the Thanksgiving cactus, is a Brazilian epiphytic cactus needing high humidity, bright indirect light, and short days to flower.
Gymnocalycium baldianum (Spider Cactus): Profile & Care
Profile of Gymnocalycium baldianum: Argentine origin, magenta-red spring flowers, cultivation, propagation, and how to separate sibling species.