What exactly is Calendula and why is it so popular?

Calendula, scientifically known as Calendula officinalis L., is a plant valued for both its medicinal and ornamental uses. It belongs to the Asteraceae family and is known for its healing, antiseptic, and anti-inflammatory properties, making it useful in health and personal care products. Specific varieties are also grown for ornamental purposes, such as in gardens.

What are the benefits of using Bahia grass in calendula cultivation?

Bahia grass (Paspalum notatum) improves soil quality by adding biomass through its roots and rhizomes. It also increases nitrogen levels through biological fixation, thanks to its relationship with the Azotobacter paspali bacterium. This grass also provides a natural way to control weeds, reducing the need for herbicides, which are not ideal for medicinal plant production.

Why is organic fertilization important when growing calendula?

Organic fertilization is important for enhancing calendula production, as demonstrated by a study that used Bahia grass as a living mulch. The study examined the effects of different levels of cured bovine manure on calendula plants grown in Cambisol soil to see if organic inputs could improve the yield and quality of calendula flowers without relying on chemical interventions.

What is Cambisol soil and why is its composition significant for growing calendula?

Cambisol soil, used in the study, has specific characteristics relevant to calendula cultivation. This soil type had a pH of 6.8 and a loamy texture, comprising 30% sand, 22% silt, and 48% clay. Understanding the soil composition is crucial for optimizing planting and fertilization strategies to support healthy plant growth and flower production.

What are sustainable agricultural practices and how do they relate to calendula farming?

Sustainable agricultural practices are methods that aim to balance productivity with economic and environmental sustainability. Minimal tillage and direct planting are examples that protect the soil and reduce disturbance. Utilizing Bahia grass as a natural weed control and organic fertilization are key components of a sustainable calendula farming approach.

Calendula flowers growing in a Bahia grass field with organic fertilizer.

Unlock the Power of Organic Calendula: Grow Vibrant Marigolds with Bahia Grass

Samir D’Costa in Climate & Environment December 2025 • 4 min read.

"Discover how to boost your calendula production using organic methods and Bahia grass cover for healthier, more abundant blooms."

In recent years, agricultural practices have shifted towards methods that enhance productivity while minimizing environmental impact. Techniques like minimal tillage and direct planting are gaining popularity for their soil protection benefits and reduced disturbance of the arable layer. These approaches are especially valuable in regions where balancing productivity with economic and environmental sustainability is crucial.

Calendula (Calendula officinalis L.), also known as marigold, is a versatile plant celebrated for its medicinal and ornamental properties. This annual, erect, and branched plant, belonging to the Asteraceae family, typically grows to a height of 30-60cm. Calendula is known for its healing, antiseptic, and anti-inflammatory actions, making it a valuable ingredient in various health and personal care products. It's also commonly grown for ornamental purposes, particularly in southern Brazil, where specific varieties have been developed for gardens.

Bahia grass (Paspalum notatum) enriches the soil by adding substantial biomass through its roots and rhizomes. It also boosts nitrogen levels via biological fixation, thanks to its association with the diazotrophic bacterium Azotobacter paspali. Cultivating calendula over Bahia grass offers a natural method for controlling weeds, reducing the need for herbicides, which have questionable use in medicinal plant production. This method aligns with sustainable agricultural practices, promoting ecological balance while maintaining productivity.

The Power of Organic Fertilization for Calendula Production

Calendula flowers growing in a Bahia grass field with organic fertilizer.

To assess the impact of organic fertilization on calendula production, a study was conducted using Bahia grass as a living mulch. The experiment, carried out in Montes Claros, MG, examined the effects of different levels of organic fertilizer on calendula plants grown in a Cambisol soil. The goal was to determine whether organic inputs could enhance the yield and quality of calendula flowers while minimizing the need for chemical interventions.

The experimental design involved randomized blocks with four treatments: 0, 3, 6, and 9 kg of cured bovine manure per square meter. Each treatment was replicated six times. Calendula seedlings were transplanted into the Bahia grass, with each experimental unit consisting of three plants. The grass was periodically cut to 5cm to minimize competition, and the plants were irrigated as needed using a perforated plastic hose system.

Soil Preparation: The experiment was performed on a Cambisol soil (pH 6.8) with a loamy texture (30% sand, 22% silt, and 48% clay).
Planting: Calendula seeds were sown in 128-cell styrofoam trays filled with commercial Plantmax substrate. Seedlings were transplanted when they reached 5 cm in height into 30 x 30 x 30cm holes, spaced 50cm apart.
Maintenance: The Bahia grass was cut regularly to reduce competition, and the calendula plants were irrigated using a laser-perforated plastic hose system.

The calendula flowers were harvested daily from the beginning of flowering, shortly after the inflorescences opened, during dry mornings. The harvested flowers were then dried in a forced-air oven at 40°C, and the dry matter was evaluated. The data was subjected to regression analysis to determine the relationship between organic fertilizer application and flower yield.

Embrace Sustainable Calendula Farming

While growing calendula with Bahia grass offers benefits like reduced weed control, it also requires more organic fertilization. It is important to assess the economics of this method in your particular setting. Future research should look into improving yields through fertilizer and cultural techniques to ensure sustainable and efficient production.