Do Dahlias Like Mushroom Compost?

Reading Time: 4 minutes 🍃

Each plant you grow in your garden has a preferred growing environment in which it will thrive. Dahlias are no different and have certain requirements that promote strong, healthy growth. Can you use mushroom compost on dahlias to give them a suitable growing environment?

Dahlias like some types of mushroom compost but not others. Well-aged mushroom compost with lower salt and nitrogen content is the best choice for growing dahlias. This promotes good flower growth rather than foliage without the risk of high salt content damaging or killing your dahlias.

Many gardeners have a favorite compost, but not all compost types are suitable for all plants. If your favorite compost is mushroom compost, you may wonder if this choice is best for your dahlias.

To get a better perspective on this, we need to understand the needs of the dahlia plants and whether mushroom compost caters to these requirements.

Table of Contents

Can You Grow Dahlias In Mushroom Compost?

Dahlias are bushy flowering plants native to Mexico and Central American countries. In 1963, Mexico declared the dahlia as their national flower.

The beautiful blooms of the dahlia have captured the eye of avid gardeners worldwide, resulting in the dahlia becoming a favored plant in gardens from the US to the UK, Africa, and Eurasia!

Dahlias can be a little picky regarding their growing environment, but they are not difficult to grow.

Dahlias are grown for their flowers, which means you need to give them compost that will promote flowering rather than foliage growth.

Mushroom compost comes in various forms, some of which can negatively impact the growth and flowering of your dahlias.

Mushroom compost can be used to grow dahlias, but you must be discerning in your choice of mushroom compost to get the best results from your dahlias.

Mushroom compost is known for its soil amendment properties, slightly less acidic pH, and high salt and calcium content.

Mushroom compost can be purchased with these characteristics in varying degrees, making it important to choose the right mushroom compost to avoid causing problems for your dahlias.

Best Soil pH For Growing Dahlias

There are varying opinions on the best soil pH for growing dahlias, with some reports promoting that dahlias thrive in a pH range of between 6.0 and 7.5. This range varies between the slightly acidic and the slightly alkaline.

In my experience, dahlias grow better when the pH is kept in the slightly acidic part of the scale. My recommended soil pH for growing dahlias is in the 6.0 to 7.0 range, not venturing into the alkaline side of the range.

Dahlias are versatile and easy-to-grow flowering plants that thrive in various soil conditions. However, keeping the soil pH slightly acidic works best for me.

Mushroom compost generally has a pH of 6.6 or 6.7, which makes it ideal to amend the soil to the correct pH level for growing dahlias.

Knowing your current soil pH before using mushroom compost is important; otherwise, the mushroom compost could push the soil pH outside the ideal range for dahlias, making the soil too alkaline.

A soil with a lower pH of 5.5 can benefit from a treatment of mushroom compost to raise the pH to a range of 6.0 or 6.2, which would be better for growing dahlias.

If your soil pH is already 6.5 or above, using mushroom compost can make your overall soil pH too alkaline, reducing the expected flowering and health of your dahlias.

Are Dahlias Salt-Tolerant?

Mushroom compost is known to have higher salinity than other compost types, which can be detrimental to plants that are not salt tolerant.

Dahlias fall into the category of plants that are not salt tolerant. This means that fresh mushroom compost, which typically has a higher salt content than aged mushroom compost, can be a problem for your dahlias.

Plants that are not salt tolerant can experience various ailments, varying from leaf burn to the plant dying from the high salt content.

If you use mushroom compost on your dahlias, it is important to select a well-aged product with lower salt content. Your local plant nursery or garden center should be able to advise you on the various mushroom composts available and which ones have a lower salinity, making them best suited for growing dahlias.

Can Mushroom Improve Soil For Dahlias?

Dahlias are not tolerant of soggy soil, which can result in the tubers suffering from rot and causing the plant to die.

Dahlias prefer moist, well-drained soil, which is where mushroom compost can be beneficial for these plants.

Mushroom compost introduces organic matter, which improves the soil structure, giving more texture to the soil. The improvement in soil structure promotes better drainage, lowering the risk of root rot while retaining enough moisture to keep the dahlias happy.

This aspect of mushroom compost is beneficial in clay and sandy soils, which may be too soggy or too dry for growing dahlias.

Mushroom compost provides a good mix of valuable nutrients for dahlias, but certain types of mushroom compost can have nitrogen levels that are not helpful during the flowering season.

Higher nitrogen levels in any compost will promote strong foliage growth but will limit fruiting and flowering in plants. Since dahlias are grown for their flowers, you should avoid any nitrogen-rich compost, which will limit their flowering potential.

Fresh mushroom compost has higher nitrogen levels, which could limit the flowering of the dahlias. Use a well-aged mushroom compost that will offer a slow release of nitrogen to limit the effect on flowering, and do not add more mushroom compost when the plant is about to start flowering.

Conclusion

Dahlias bring beauty and elegance to a garden with the exquisite blooms they are famous for and why they are featured in many gardens. While they are easy to grow, they need an environment that will encourage their flower production.

Mushroom compost can be a good choice for dahlias as long as you are selective with your mushroom compost choice and you know your current soil pH.

Dahlias are a bit particular regarding their soil needs, but they can benefit from the informed use of mushroom compost to help them flourish!

References

https://davesgarden.com/community/forums/t/582677/#b

Was this article helpful?

YesNo