Do Hydrangeas Like Mushroom Compost?

Do Hydrangeas Like Mushroom Compost

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Do you have a green thumb? Love to garden? Hydrangeas are very popular flowering shrubs and can be relatively easy to take care of as long as you know what they need. One question that often comes up is whether or not these delicate blooms will enjoy mushroom compost.

Hydrangeas only like mushroom compost if the alkalinity of the compost raises the soil pH to between 6.0 to 6.2 for the plants to thrive. The other aspects of mushroom compost, such as the slow release of nutrients, improvement of soil structure, moisture retention, and drainage, benefit hydrangeas.

Hydrangeas are grown for their impressive floral displays from early spring to late autumn, but the compost you use to feed the plants can affect the flowering. Mushroom compost has different characteristics than normal compost, which means you must use it judiciously with your hydrangeas.

Can You Use Mushroom Compost For Hydrangeas?

Hydrangeas are a popular choice for gardeners because of their beautiful flowers. But what type of soil do they need? Can you use mushroom compost with these showy plants, or would an alternative be a better choice?

The gardening community has a love-hate relationship with mushroom compost, with some gardeners saying it is the best compost to use, while others say you should stay away from it because of the pH and the salinity of the mixture.

The reality is in the middle ground and understanding the characteristics of mushroom compost and the needs of your plants.

Mushroom compost can be used with hydrangeas, and the hydrangeas will love it if the characteristic of the mushroom compost produces an ideal growing environment for the plants.

In certain circumstances, mushroom compost can be detrimental to your hydrangeas, which is why you need to understand the needs of the plant and what mushroom compost offers before you use it on your plants.

Is Mushroom Compost Too Alkaline For Hydrangeas?

One of the characteristics of mushroom compost is the relatively alkaline nature of the compost. Most plants prefer a soil pH in the range of 5.5  to 6.5, whereas the pH of mushroom compost is 6.6, or 6.7, and in some cases, higher.

This can be a problem for plants that love acidic soil, but it is good news for plants that prefer slightly less acidic soil.

Mushroom compost’s alkalinity makes it ideal to amend soil that is too acidic and raise the pH to more tolerable ranges for the hydrangea plants.

If you’re wondering whether mushroom compost is too alkaline for hydrangeas, the answer is yes and no, since it depends on the type of mushroom compost you use. 

If you use a well-aged mushroom compost that’s been sitting for a while, it is less likely to dramatically affect your soil’s pH. However, using fresh mushroom compost can raise the pH of your soil, making it more alkaline.

This makes it important to know your soil pH before using mushroom compost with your hydrangeas. Hydrangeas prefer soil with a pH range of between 6.0 and 6.2, which is more acidic than mushroom compost.

Raising the growing medium pH to above 6.4 can limit the hydrangea’s ability to absorb iron, negatively affecting the plants.

If your soil is naturally alkaline, using mushroom compost is not a good idea since it may raise the overall soil pH to a detrimental level to the hydrangeas.

However, if you’re growing hydrangeas in an area with a naturally low pH, like peat soils, then using mushroom compost can raise the soil’s pH level to the ideal range for hydrangea growing. 

Certain species of hydrangea will produce different colored flowers based on the soil’s pH level. With these hydrangea species, using mushroom compost to raise the alkalinity of the soil slightly will inhibit the absorption of aluminum ions, causing the plant to produce pink or red flowers.

Hydrangeas can absorb aluminum ions more easily when the soil is more acidic, which has a bluing effect on the flowers, causing the flowers to bloom blue.

Can Hydrangeas Tolerate The Salinity Of Mushroom Compost?

Another characteristic of mushroom compost is the high salinity, which can burn plants that are not salt tolerant.

Hydrangeas are salt-tolerant plants, but tolerance levels vary between the different hydrangea varieties. This means that you should choose the hydrangea varieties that are more salt tolerant if you will be using mushroom compost in your garden. 

The hydrangea varieties with the highest salt tolerance are the Ayesha, the Sabrina and Selina hybrids, Mathilda Gutges, and Merrit’s Supreme.

How To Use Mushroom Compost With Hydrangeas

Mushroom compost can help to keep these beautiful flowers looking their best. However, you don’t want to go overboard with the mushroom compost, as too much can actually harm your hydrangeas. So, how much mushroom compost can you use with hydrangeas?

A good rule of thumb is to use no more than 1 part mushroom compost to 10 parts soil. So, if you’re mixing up a pot of soil for your hydrangeas, you would only add 1 cup of mushroom compost for every 10 cups of soil.

Mushroom compost can be used as a top dressing as mulch or mixed into the soil before planting. To use it as a mulch, apply a thin layer of compost to the soil’s surface around the base of the plant. Water thoroughly to help distribute the nutrients.

Mushroom compost can also make a compost tea or liquid fertilizer for your hydrangeas. Steep 1 to 2 cups of mushroom compost in a gallon of water for 24 hours. Strain and apply to the soil around the base of the plant every 2-4 weeks during the growing season.

What Type Of Soil Do Hydrangeas Prefer?

Hydrangeas are garden plants that prefer slightly acidic soil to thrive. This means that if you want to raise healthy hydrangeas, you should aim for soil that is slightly acidic but not too acidic. One way to manage the soil pH is by using mushroom compost in your garden to control or amend the pH.

Hydrangeas prefer soil with good organic content for soil structure, aeration, and moisture retention. Mushroom compost offers a good level of moisture retention and improves soil structure and drainage. 

This makes it a good compost to use if you have done your research on the current pH of your garden soil.

 If you’re not sure where to find mushroom compost, your local gardening center should have it in stock. Your hydrangeas will be healthy and beautiful with the right amount of mushroom compost. 


Mushroom soil offers many benefits for hydrangeas, but you need to know the condition of your garden soil before applying mushroom compost. Mushroom compost can amend the soil to provide the ideal pH for growing hydrangeas, providing good moisture retention and a slow release of nutrients. 

In some instances, using mushroom compost with your particular soil type may not be good for your hydrangeas, so be sure to test your soil pH before choosing this compost for your hydrangeas.


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