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2 Sterilized Rye Bags with Injection Port & 1 Bag of 5lb Manure Substrate
2 Sterilized Rye Bags with Injection Port & 1 Bag of 5lb Manure Substrate
$25.95
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Bulk Substrate

Bulk Substrates

Below you can find bulk substrate products for mushroom cultivation, available in 5 x 5lb bag sets, 12-pack jar sets, and multi-bag configurations. Out-Grow carries manure-based, wood-based, straw-based, and grain-based bulk substrate, all arriving fully prepared and ready for inoculation.

Manure-Based Bulk Substrate

Manure-based bulk substrate is available in 5 x 5lb bag sets in straight manure and 50/50 horse manure and straw blend formats.

Wood-Based Bulk Substrate

Wood-based bulk substrate is available in 5 x 5lb bag sets for wood-decay species.

Grain-Based Bulk Substrate

Grain-based bulk substrate is available in 5 x 5lb bag sets and 12-pack jar sets. Options include rye berry, popcorn, red milo, white milo, white millet, BRF, and Mega Mix formulations.

Bulk All in One Grow Bags

Our all-in-one grow bags are available in an 8-pack configuration for growers running multiple simultaneous grows.

Browse the full bulk substrate collection below.

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5 Pounds Pasteurized Manure Mushroom Substrate (5 x 1lb Bags)
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5 Pounds Pasteurized Manure Mushroom Substrate (5 x 1lb Bags)
$39.00
Five sealed rectangular blocks of 50/50 horse manure and straw mushroom substrate, each weighing five pounds. The blocks are tightly packed in clear plastic, showing a dark mixture of organic material with visible straw strands throughout.
50/50 Horse Manure and Straw Bulk Substrate (25 lbs)
$84.00
All In One Mushroom Grow Bags 8-Pack
All In One Mushroom Grow Bags 8-Pack
$129.95
Twelve half-pint jars filled with a sterilized mix of brown rice flour and vermiculite substrate, arranged in a grid. The jars feature self-healing injection ports on the lids, ideal for easy inoculation and efficient mushroom cultivation.
BRF Bulk Substrate Jars (12-Pack)
$63.00
Five sealed rectangular blocks of manure-based mushroom substrate, each weighing five pounds. The blocks are tightly wrapped in clear plastic, showing a dark, finely textured organic material. Ideal for bulk mushroom cultivation.
Manure Based Bulk Substrate (25 lbs)
$84.00
Twelve quart-sized jars filled with a sterilized mix of grains, including rye, milo, and popcorn. The jars are arranged in a grid and feature self-healing injection ports on the lids, designed for easy inoculation and optimal mushroom cultivation.
Mega Mix Bulk Substrate Jars (12-Pack)

1 review
$116.25
Five sealed mushroom grow bags filled with fully hydrated and sterilized popcorn grains, each weighing five pounds. The bags are tightly wrapped in clear plastic and feature self-healing injection ports, perfect for inoculation and bulk mushroom cultivation.
Popcorn Bulk Substrate Grain Bags (25 lbs)
$130.50
Twelve quart-sized jars filled with fully hydrated and sterilized popcorn grains, arranged in a grid. The jars feature self-healing injection ports on the lids, making them ideal for easy inoculation and efficient mushroom cultivation.
Popcorn Bulk Substrate Jars (12-Pack)
$116.25
Twelve quart-sized jars filled with fully hydrated and sterilized red milo grains, arranged in a grid. The jars feature self-healing injection ports on the lids, making them ideal for easy inoculation and efficient mushroom cultivation.
Red Milo Bulk Substrate Jars (12-Pack)
$116.25
Five sealed mushroom grow bags filled with fully hydrated and sterilized rye berries, each weighing five pounds. The bags are tightly wrapped in clear plastic and feature a self-healing injection port, ideal for inoculation and bulk mushroom cultivation.
Rye Berry Bulk Substrate Grain Bags (25 lbs)
$130.50
Twenty-five sealed mushroom grow bags, each filled with one pound of fully hydrated and sterilized rye berries. The bags are neatly arranged in a grid, wrapped in clear plastic with visible filter patches, perfect for large-scale mushroom cultivation.
Rye Berry Bulk Substrate Grain Bags (25-Pack)
$147.50
Twelve quart-sized jars filled with fully hydrated and sterilized rye berries, arranged in a grid. The jars feature self-healing injection ports on the lids, making them ideal for mushroom cultivation and inoculation in bulk.
Rye Berry Bulk Substrate Jars (12-Pack)
$116.25
Twelve quart-sized jars filled with fully hydrated and sterilized white millet grains, arranged in a grid. The jars feature self-healing injection ports on the lids, making them ideal for easy inoculation and efficient mushroom cultivation.
White Millet Bulk Substrate Jars (12-Pack)
$116.25
Twelve quart-sized jars filled with fully hydrated and sterilized white milo grains, arranged in a grid. The jars feature self-healing injection ports on the lids, making them ideal for easy inoculation and efficient mushroom cultivation.
White Milo Bulk Substrate Jars (12-Pack)
$116.25
Five sealed mushroom grow bags filled with wood-based mushroom substrate, each weighing five pounds. The bags are tightly wrapped in clear plastic, displaying the finely textured wood fibers used for growing wood-loving mushrooms. Ideal for bulk cultivation.
Wood Based Bulk Substrate (25 lbs)
$115.00