5lbs. Organic Wood-Lover Substrate

High-yield, supplemented sawdust mushroom substrate

5lbs. Organic Wood-Lover Substrate
$30 - $45 suggested donation

A 5lb. bag of hydrated, sterilized organic rye grain in an injection-port spawn bag, ready to inoculate with the mushroom culture of your choice.

Our hardwood-based substrate is lovingly mixed by hand in small batches using only wholesome, natural and organic ingredients. High in nitrogen and packed with nutrients, this supplemented sawdust recipe is formulated for wood-loving mushrooms to maximize biological efficiency and keep the mycelium thriving for many consecutive harvests.

Perfect for both indoor and outdoor mushroom cultivation projects, sawdust spawn is versatile. It can be used as a stand-alone "fruiting block" for simple, small-scale mushroom cultivation (this is the base of all our wood-loving mushroom kits), and it can also be used for starting mushroom patches, inoculating logs or spawning into bulk substrates.

Ingredients: Spring water, wild alder sawdust, organic wheat straw, organic worm castings, organic coconut coir, vermiculite, organic wheat bran, gypsum, chalk, potash.

The specialized injection-port spawn bags make it easy to inoculate your grain with a liquid culture syringe. The 0.2 micron sir filter keeps it sterile while it incubates. Once the mycelium has a running start in sterile conditions, mature grain spawn is naturally resistant to contamination and can be handled directly for spawning bulk substrates like sawdust, wood chips, dowels and straw.

Make it a kit! Get a discount when you include a Fungaia liquid culture syringe with your substrate, or check out our all-in-one kits for growing Lion's Mane, Reishi, Oysters and more.

Organic Matters

Mushrooms bioaccumulate toxins at many times the ambient levels of their environment. While this is good news for our soils, it's not for our bodies. With ever-increasing concentrations of pesticides and other toxins in our soil, food and water, it's more important than ever to find sources we can trust. 

At Fertile Substrate, we are meticulous about our ingredients, from our spring water to the wood we burn for our homemade potash pH booster. We believe that every detail has significance, and we are dedicated to our craft. It won't be hard to see the difference, and we promise that your fungus will thank you, too.

Our Guarantee

We guarantee that your substrate will arrive intact and free of contaminants or we will replace it. Once it has been inoculated, this gurantee only applies if you use a liquid culture from Fungaia.


Info & Terms

We are committed to providing exceptional customer service.

How It Works

For both privacy and security, we do not process credit cards on this website. Instead, after you place an order, you will receive an email with a link to pay using a secure, trusted third party (or instructions if paying with cash). Unpaid orders will be cancelled after 7 days (30 days for cash orders).

We do our best to process invoices and ship orders within 1-3 business days.


We do not sell or distribute any personal customer data to any third party for any reason.

Cancellation Policy

Excluding custom orders, your order may be cancelled for a full refund at any time until they have been shipped. Once an order is shipped it will not be refunded.

Return Policy

Due to the perishable nature of live biological specimens, we do not accept returns. In the rare case that you should find, with reasonable assurance, that our products were compromised in any way upon arrival, we will promptly replace them at no cost to you. We do not offer refunds after products have been shipped.

Lost or Damaged Packages

When an order is shipped, we provide tracking information. If a package is lost or damaged in transit, we will work with the postal carrier to recover the cost and send a free replacement. However, we are not responsible for orders which are lost or misplaced after they have been delivered by the carrier.


We reserve the right to refuse service to anyone for any reason.