Podcast Summary: "Meterse en un jardín | Cactus y otras plantas que lo parecen, pero no lo son"

Podcast: Hoy por Hoy (SER Podcast)
Host: Àngels Barceló
Featured Guest: Eduardo Barba
Date: September 30, 2025

Overview

This episode of "Hoy por Hoy" dives into the fascinating and sometimes confusing world of cacti and succulent plants, focusing on the differences between true cacti and plants that only mimic their appearance. Eduardo Barba joins Àngels Barceló in-studio, surrounded by an impressive variety of cactus specimens, to clarify misconceptions, share expert advice, and answer listener questions about plant care.

Key Discussion Points and Insights

1. Rescuing Plants at the "Hospital" de la Radio

• [01:08] Eduardo Barba describes the routine arrival of neglected and anonymous plants at the radio station, often left in poor condition with the hope of reviving them.
  • Quote: “Son plantas que esperan el milagro. Exacto. Están un poco desahuciadas.” (C, 01:10)
• Today’s rescue is a severely dried-out Nephrolepis (sword fern), which Eduardo sets out to revive by cutting away dead fronds and giving it proper care.
  • Quote: “Lo que haré hoy será cortar todo lo que está seco y vamos a darle buen cariño y a ver si rebrota este helecho.” (C, 01:49)
• Àngels humorously insists that the anonymous donor reveal themselves, comparing the act to abandoning a baby on someone’s doorstep.

2. The Cactus Collection: Origins and Donor

• [03:20] The studio receives a large gift of cacti and succulents from the Jardín Botánico Mora y Bravard in Casarabonela, Málaga, facilitated by Pepe Rubio.
  • Quote: “Gracias a sus fundadores... hemos recibido la donación de esta importante colección de cactus y de otras plantas suculentas.” (C, 03:27)
• Barba promotes the “Museo del Cactus” in Casarabonela as a must-visit location.

3. What Makes a Plant a "Cactus"?

• [04:26] Not all plants that resemble cacti are true cacti. The defining feature is the areola—a unique growth structure from which spines and flowers emerge.
  • Quote: “Para que una planta se le considere un cactus... tiene que tener una estructura que es única... la areola... el puntito del que surgen espinas, si es que tiene que tenerlas o no…” (C, 04:36)
• Some true cacti lack spines entirely (“inerme”), relying on other means for protection (toxicity, sap, etc.).

4. The Function of Cactus Spines

• Spines serve multiple purposes beyond defense:
  • Protection from herbivores: “Las espinas de los cactus son defensa para ellos.” (B, 06:12)
  • Temperature regulation and shading: Dense spines help lower body temperature and create microshades.
  • Dispersal: Some cacti have hooked spines that latch onto animal fur for seed/hybrid propagation.
  • Quote: “Esas espinas... también provocan un sombreo en el propio cuerpo... produce una bajada de temperatura.” (C, 06:14)
• Discussion about how some species, like mammillaria, can even cling to animals to spread.

5. Popular Cactus Varieties—What’s in the Studio

• [07:57] Astrophytum capricorne vs. Astrophytum myriostigma:
  • Only one bears spines (capricorne); the other is inerme (myriostigma).
  • Quote: “Uno tiene pinchos y otro no. Aquí es donde veríamos claramente como estas areolas... no han producido [espinas].” (C, 08:18)
• Kroenleinia grusoni ("asiento de suegra"):
  • Most recognizable and photographed cactus, known for its round shape and spines.
  • Quote: “Es el típico cactus que habréis visto mil y una veces, porque es la típica gran pelota... llena de espinas de un color amarillo dorado increíbles...” (C, 12:09)
• Mammillaria plumosa:
  • Soft, hair-like spines that protect against sunlight rather than from predators.
  • Quote: “Estas areolas han producido esta casi pilosidad espinosa suave, que protege del exceso de radiación solar.” (C, 13:41)

6. Caring for Cacti: Pot Size, Watering, and Light

• [08:49] Pot Size:
  • Smaller pots restrict cactus growth but don't harm the plant outright.
  • Larger pots allow better root spread, enhancing health and size.
  • Quote: “Si me pasas a una maceta un poquito mayor, yo te lo agradezco... va a estar siempre mucho mejor...” (C, 09:36)
• [09:59] Watering:
  • Reduce or stop watering in colder months when temperatures drop below 10°C, especially for outdoor cacti.
  • Indoors, light reduction—not just temperature—should dictate watering frequency.
  • Quote: “En los meses fríos... podemos ir acortando riegos o incluso detenerlos.” (C, 10:21)
• Finger test not always reliable—let the substrate dry between waterings.

7. Cactus Myths: Bad Luck and Superstition

• Some believe cacti bring bad luck. Eduardo shrugs this off humorously.
  • Quote: “Las supersticiones están hechas para creérselas y si no te las crees... la vida te va genial.” (C, 07:37)

8. Propagation: Should You Root Cuttings in Water or Soil?

• [14:27] Listener Question: María from Alcalá de Henares asks if it’s better to root cuttings in water or soil.
• Eduardo’s Advice: Try both; water is quick and easy for most, but professionals use substrate for stability. For cacti/succulents, let the cutting dry before planting to avoid rot.
  • Quote: “Ante la duda, prueba las dos vertientes... normalmente en agua van a sacar raíz muy rápidamente...” (C, 14:38)

9. When “Fake” Cacti Fool Us: Euphorbia Obesa

• Appears to be a cactus but is a convergent-evolution euphorbia and actually related to the poinsettia.
  • Quote: “Si yo te digo que esta planta es pariente de la flor de Pascua, ¿Qué me dices?... Es que dices, pero si es un cactus.” (C, 16:13)
• Discussion of "living stones" (Lithops), another non-cactus with cactus-like features and remarkable flowers.

10. Do All Cacti Flower?

• Yes, but some take years to mature before blooming, while others (like mammillaria) can flower when young. Blooms are often brief but spectacular.
  • Quote: “¿Y todos los cactus florecen? Claro que sí... es una belleza absoluta...” (C, 17:17)

Notable Quotes & Memorable Moments

• On Plant Rescue:
  • “Son plantas que esperan el milagro... están un poco desahuciadas.” — Eduardo Barba (01:10)
• On Plant Abandonment:
  • “Esto es como cuando se dejaba antiguamente esos bebés a la puerta de alguien... cuídalo tú. Esto es un poco así.” — Eduardo Barba (02:12)
• On Cactus Structure:
  • “Tiene que tener una estructura que es única... la areola...” — Eduardo Barba (04:36)
• On Spines’ Functions:
  • “Esas espinas... provocan un sombreo... produce una bajada de temperatura.” — Eduardo Barba (06:14)
• On Superstitions:
  • “Las supersticiones están hechas para creérselas y si no te las crees a lo mejor la vida te va genial.” — Eduardo Barba (07:37)
• On Euphorbia Obesa:
  • “Si yo te digo que esta planta es pariente de la flor de Pascua, ¿Qué me dices?... Es que dices, pero si es un cactus.” — Eduardo Barba (16:13)
• Moment of Pain:
  • “Uy. Te acabas de pinchar.” (B, 16:50)
  • “Bueno, el Astrophytum Capricornio. Sí, me ha dado un viaje.” (C, 16:51)

Timestamps for Important Segments

• 01:08 – Rescue mission: The fate of the anonymous sword fern.
• 03:20 – The story behind the cactus collection and its origins.
• 04:26 – What defines a real cactus? The role of the areola.
• 06:12 – Spines as defense and microclimate regulators.
• 07:57 – Astrophytum species in the studio.
• 08:49 – Cactus care: Pot size, watering practices.
• 09:59 – Ideal watering methods and seasonal adaptation.
• 14:27 – Listener question: Cuttings—water or soil?
• 15:52 – Euphorbia obesa, the “fake” cactus.
• 16:50 – A painful encounter with Astrophytum spines.
• 17:17 – The surprising beauty and timing of cactus flowers.

Conclusion

Eduardo Barba demystifies cacti, unpacks their care, and corrects a few popular misconceptions, transforming “cactus confusion” into curiosity and awe. The episode is a lively, good-humored guide to caring for cacti and succulents, with practical advice for beginners, as well as delightful trivia for plant aficionados.

Listeners are left with practical insights:

• Don’t overwater or rush to repot cacti.
• Not all spiny plants are cacti and not all cacti have spines.
• Experiment with propagation, and debunk the myths—cacti are lucky if you care for them right!

For plant lovers and cactus novices alike, this is a down-to-earth and informative episode that brings the desert to life.