Skip to content

Rockwool / Stonewool 8 Inch Big Mama Block






Made in Denmark since 1969, Grodan rockwool (also called stonewool) is widely recognized as the ideal soilless substrate. For any growing application, rockwool offers speed, ease of use, and cleanliness. Rockwool is an alternative to coco coir and expanded clay for hydroponic applications.

  • 8″ Big Mama Blocks can be used as an intermediary, but are an excellent final container for planting.
  • Individually wrapped cubes hold the rockwool’s shape and prevent algae growth.
  • Grodan A-OK Staters and Macroplugs fit snugly into the pre-formed hole on the top of the 8″ Big Mama Block.

In stock

Your Garden's Success is our #1 Priority

HTG Supply is committed to providing you with the very best products, pricing and service in the industry. We will ship your order fast and discreetly packaged to protect your privacy. Buy with confidence knowing your HTG Supply purchase includes simple returns as well as lifetime product support. Call our team of real growing experts with your purchasing or product use questions, and we will be here to help!

See it for less somewhere else? Give us a call and we’ll beat any online competitor’s price!

Customer Service:  1-866-710-GROW (4769) | | Hours: Mon-Fri 9:00 a.m. to 5:00 p.m.


Big Mama is the largest block ever produced by Grodan. It is 8″ square and contains over twice the amount of wool as the popular Hugo block. This block is big enough to grow a large plant for its entire life! When your plant outgrows its current block, just place it on top of Big Mama. Big Mama is solid wool and does not have a precut hole thus making it suitable to hold any size smaller block on top (even a Hugo).

1. Pre-soak and flush to waste as recommended for all blocks.
2. Start with a well established plant with roots just beginning to come through in minimum 3” block.
3. Place the plant on the Big Mama.
4. Due to the height of Big Mama, top watering systems are recommended.

Weight 1.5 lbs


There are no reviews yet.

Only logged in customers who have purchased this product may leave a review.