Mushroom Compost Bulk Bag

Our quarter-tonne Mushroom Compost Half Bulk Bag is an excellent natural soil enhancer. It’s made from a well-balanced blend of wheat straw and horse manure, carefully composted to create a nutrient-rich amendment.

Incorporating mushroom compost into your garden is an effective way to improve soil health and boost plant growth. This organic material enhances soil structure, increases moisture retention, and enriches the soil with vital nutrients. Additionally, its natural disease-fighting properties help protect plants from infections, fostering healthier growth. Packed with beneficial microorganisms, mushroom compost supports soil fertility and improves nutrient absorption. By using this eco-friendly compost, you’re repurposing agricultural by-products that would otherwise go to waste, contributing to sustainable gardening while improving soil quality and plant productivity.

Our half bulk bag measures 45 x 85 x 85 cm, holds approximately 250 kg, and is available for UK-wide delivery straight to your door.

For larger orders, please get in touch with us to discuss pricing and delivery options.

FAQs About Spent Mushroom Compost

What is spent mushroom compost?

Spent mushroom compost (SMC) is the leftover material from mushroom farming. It consists of organic ingredients like straw, manure, and gypsum that have been used as a growing medium. While it's termed "spent," it still holds valuable nutrients for soil improvement.

How is spent mushroom compost produced?

SMC is created by composting a mixture of organic materials, including straw, horse or poultry manure, and gypsum. After serving as a substrate for mushroom growth, the remaining compost is collected and repurposed for gardening and landscaping.

What are the advantages of using spent mushroom compost?

• Enhances soil structure and aeration
• Improves moisture retention, reducing the need for frequent watering
• Adds essential nutrients to the soil
• Helps suppress some soil-borne diseases
• Provides an eco-friendly alternative to synthetic fertilizers

Can spent mushroom compost be used for all plants?

It benefits a wide range of plants, such as vegetables, flowers, shrubs, and trees. However, due to its slightly alkaline pH, it may not be suitable for acid-loving plants like blueberries, rhododendrons, and azaleas.

How should I apply spent mushroom compost in my garden?

It can be used as:

• A soil conditioner by blending it with garden soil (recommended ratio: 1 part compost to 3 parts soil)
• A mulch to help retain moisture around plants
• A lawn top dressing to improve soil health
• A potting mix additive when combined with other compost types

Can spent mushroom compost harm plants?

While generally safe, excessive application may lead to high salt concentrations, which can affect sensitive plants. To prevent this, mix it with soil or allow it to age before use.

Does spent mushroom compost have a strong odor?

Properly aged spent mushroom compost has a mild, earthy scent similar to fresh soil. If it smells strongly of ammonia or sulfur, it may need further curing.

Is spent mushroom compost organic?

It is made from organic materials, but whether it is officially certified as organic depends on the production process. If organic certification is a priority, check with your supplier.

Can I make my own spent mushroom compost?

Yes! If you cultivate mushrooms at home, you can reuse the leftover compost by allowing it to mature for a few weeks before incorporating it into your soil.