Gardens that breathe: plants that capture CO2 and withstand drought

When it comes to the fight against climate change, plants are among our most silent but essential allies. Every plant we grow, even in our own garden, helps to capture carbon dioxide from the atmosphere and return it to the soil, improving its fertility and contributing to so-called carbon sequestration.

However, not all plants do this in the same way. Some species have evolved to absorb CO2 even in difficult conditions where most plants slow down or stop photosynthesis, such as during long periods of drought or heatwaves. Among these, the most interesting for anyone wanting a sustainable garden are CAM plants and C4 plants.

• CAM vs C4: which is more efficient in a dry garden?
• The CAM plants in your garden: hardy, beautiful and sustainable
• A garden that looks to the future

CAM vs C4: which is more efficient in a dry garden?

C4 plants – such as maize, sorghum or sugarcane – are highly efficient at capturing large amounts of CO2, especially in hot, sunny environments. However, these plants grow best with abundant irrigation and are not always suitable for domestic settings or low-maintenance gardens.

The real stars for sustainable gardening in increasingly dry climates are, instead, CAM plants (Crassulacean Acid Metabolism). These plants use a surprising strategy: they absorb carbon dioxide at night, when temperatures are cooler and evaporation is minimal. During the day, however, they close their pores to prevent water loss while continuing to use the stored CO2. This makes them incredibly drought-resistant and able to continue photosynthesis even when other plants “stop.”

In short, they do not necessarily absorb more CO2 than other plants in ideal conditions, but they do so when other plants stop, in the difficult climatic conditions that characterize our gardens in summer. And that is precisely what makes them valuable in a world that is becoming increasingly hot and dry.

The CAM plants in your garden: hardy, beautiful and sustainable

At Botanical Dry Garden, you will find several CAM species perfect for Mediterranean gardens or sunny terraces.

• Sedum spectabile and Sedum sexangulare: with their fleshy rosettes and abundant flower heads, they create flowering carpets that thrive without continuous irrigation.
  
  
• Malephora lutea and Malephora crocea: ground-covering succulents, ideal for embankments or low-maintenance flowerbeds, with bright, long-lasting flowers.
  
  
• Suaeda vera, although not a CAM plant, is highly adapted to extreme conditions such as salinity and heat, and is perfect for coastal or arid environments.
  
  
• Anthyllis barba-jovis, finally, is a hardy Mediterranean plant that is not a succulent but enriches the soil and promotes biodiversity.
  
  

These plants not only reduce the need for water and fertilizers, but also continue to help the climate even during the driest months, helping to keep local carbon capture active.

A garden that looks to the future

Creating a garden with CAM plants means building a more resilient ecosystem. It does not require continuous irrigation, does not fear long summer droughts and, at the same time, helps improve soil health and reduce CO2 in the atmosphere.

Choosing plants like these is not just an aesthetic decision or a practical choice for a low-maintenance garden: it is also a climate choice, perfectly in line with the environmental challenges that lie ahead.