Can Marigolds Grow In Ericaceous Compost?

Can Marigolds Grow In Ericaceous Compost

Reading Time: 5 minutes 🍃

Marigolds are a gardener’s friend because they are beautiful and benefit the garden by keeping unwanted pests away. If you have an acidic bed for other acid-loving plants, can you grow marigolds in ericaceous compost?

Marigolds cannot grow in ericaceous compost because the pH of the growing environment is too low and outside of the ideal 6.0 to 7.0 tolerance range for the plant. Ericaceous compost can be used to amend alkaline soils above 7.0 pH to within the ideal range for growing marigolds. 

Marigolds are a plant with so many benefits that every gardener should consider planting them in their gardens or containers. Understanding the plant’s needs will give you the information to discover whether marigolds will grow in ericaceous compost or if it is a bad idea. 

Is Ericaceous Compost Good For Growing Marigolds?

When considering the best soil or compost for growing any plant, you must understand the environmental conditions that provide the optimal growing potential for the plant.

This gardening principle applies to marigolds and any other plant you are contemplating for your garden, container, or growing system.

Soil pH is one of the environmental factors that many gardeners forget to consider, which can impact the plant’s growth and overall health. Gardeners familiar with growing acid-loving plants are more familiar with this concept.

To determine if ericaceous compost is suitable for growing marigolds, we need to know the optimal soil pH that results in thriving marigold plants.

What Is The Ideal Soil pH For Growing Marigolds?

Marigolds are easy to grow if provided with conditions resembling their natural habitat. What this means for us as gardeners is that we need to create an environment in which the plant can make use of all the nutrients available to it in the soil or growing medium.

The soil pH affects the availability of certain nutrients and minerals in the soil and the plant’s ability to absorb these nutrients via its root system.

The ideal soil pH for marigolds is between 6.0 and 7.0, with an average of 6.5 being the optimal pH where the plant can thrive. 

If the soil pH is towards the upper or lower end of the marigold’s pH tolerance, it will still grow, but the plant may not be as healthy or productive as it can be.

So how does ericaceous compost fit into the needs and requirements for marigolds to grow well in your garden or container?

Can Ericaceous Compost Benefit Marigolds?

Ericaceous compost is designed to have a low pH because it is intended as a soil amendment compost to create the ideal growing environment for acid-loving plants.

The ideal soil pH for marigolds is 6.5, which is only slightly acidic, compared to the low pH of ericaceous compost, between 4.0 and 5.0.

The low pH levels of ericaceous compost will amend alkaline or slightly acidic soils to a pH of about 5.5, which is too acidic for marigolds to flourish.

Consequently, marigolds will not grow well if they are grown in soil modified by ericaceous compost for acid-loving plants.

This does not mean that ericaceous compost has no value for gardeners that want to grow marigolds. If your soil is particularly alkaline, such as in more arid climates, ericaceous compost can be used to lower the soil pH to within the ideal range for growing marigolds.

When ericaceous compost is used in this way, it not only provides the right pH, but the other characteristics of the compost will benefit the marigolds.

What Are The Other Growing Requirements For Marigolds?

Many plants fall under the marigold name, from Calendula to African Marigolds and Mexican and French Marigolds. They all have similar environmental requirements for ideal growing conditions.

As we have mentioned, marigolds are easy to grow, especially if you have average soil that is not too acidic nor too alkaline, but the plant has some other basic requirements that will result in the plant growing to its best potential.

Soil Requirements For Marigolds

Besides the correct soil pH, the best soil type for growing marigolds is well-draining. The soil should have organic matter for water retention, but not too much.

However, do not add too much organic matter, as marigolds do not like super nutrient-rich soil. The plants grow better if they have to work a little for their nutrients.

This aspect of marigolds is where ericaceous compost can be beneficial if you have used it to amend the pH for growing these flowers. Ericaceous compost is typically not as nutrient-dense as other standard compost types.

Water Requirements For Marigolds

Young marigold plants or seedlings should be watered regularly, and the soil should not be left dry for more than a day or two, particularly in hot weather.

Once the plants have had a few weeks of growth to establish their root systems, they are tolerant of drier conditions and will grow well and bloom with a once-a-week watering regimen.

Light Requirements For Marigolds

Marigolds are heat and light-loving plants and require full sun to grow to their maximum potential. If they are shaded, the marigold plants will reach for the light and become leggy and weak.

Less light will also reduce the flowering potential of the marigolds, and you will have a less-than-spectacular floral display.

Temperature Requirements For Growing Marigolds

Marigolds prefer warm climates and consequently grow well in USDA zones 2 through 11. Marigolds prefer to grow in temperatures above 40°F or 4°C, so you should only plant them once the outside temperature does not drop below this level.

Marigolds tolerate a wide range of climate humidity levels but tend to develop powdery mildew in excessively humid conditions. Planting them in a breezy, sunny location will prevent mildew from developing on the leaves.

Why Should You Grow Marigolds?

Marigolds bring many benefits to your garden, so I recommend that every gardener try growing these phenomenal plants.

Some of the benefits of marigolds include the following.

  • The flowers are edible. The colorful flowers can be added to a salad or included in soups, drinks, and pesto, bringing a delicate mild flavor. Marigold flowers can also be used to make herbal tea.
  • Soil nematode control. Marigolds discourage nematodes in the soil responsible for various rooting ailments in other plants.
  • Attract beneficial insects. Marigolds attract predatory insects such as ladybugs to your garden to control insect pests.
  • Repel mosquitoes. Marigolds discourage mosquitoes, so planting them under windows is a good option.

Check out: Do Broom Plants Need Ericaceous Compost?


Marigolds do not like very acidic soils or growing environments, so in normal circumstances, ericaceous compost is not an ideal addition to their growing environment. Ericaceous compost can be used in extremely alkaline soils to lower the pH to within the tolerance levels of marigolds.

Marigolds offer many benefits to your garden and can be used as a natural health food and treatment for certain ailments as well as for pest control. 


Was this article helpful?

Team Leafy

Hi! Thanks for reading our article, we hope you enjoyed it and helps make your garden grow greener. If you found this article helpful, please share it with a friend and spread the joy. Plant small. Grow big!

Recent Posts