

Grodan Stonewool (rockwool) is made from molten rock spun into cotton candy-like fibers and then compressed into cubes, blocks, or slabs. Where other rockwool brand manufacturers cut all sizes from one batch of wool, Grodan is unique by making different types of fibers. The purpose is to support the requirement of the plant in the different plant stages. Grodan has a tremendous capacity for absorbing nutrient solution while retaining plenty of oxygen for rapid plant growth. Grodan comes in graduated sizes. Seedlings started in cubes are easily transferred to blocks and then onto slabs, if desired. Seedlings or cuttings started in the Grodan cubes can also be transplanted into more traditional planters and growing mediums. Grodan Blocks -Grodan Delta blocks are the most uniform blocks available on the market. They feature improved grooves at the base to promote better drainage. These growing blocks are used for direct sowing or "blocking on" of Macro and Multiblock raised plants. AO 36/40 plugs fit well into the hole sizes provided by the blocks. The blocks can then be placed on top of a slab to provide for a larger growing volume. It provides enough growing volume to support a larger plant, so it does not need to be placed on top of a larger slab. Review: best 4x4 veg cubes!! - Good quality as usual with Grodan cubes, had excellent results for a 3 week veg. Review: If you're in the know, it's the way to go. - These are great. Plants grow like crazy in rockwool. The Dutch refined indoor cultivation to an art. The only reasons for bad reviews are whining about price, not understanding that it's a pack of 6, and not knowing how to use the cubes.
| ASIN | B01AYRWWKY |
| Best Sellers Rank | #1,359,671 in Patio, Lawn & Garden ( See Top 100 in Patio, Lawn & Garden ) #12,265 in Garden Fertilizers |
| Customer Reviews | 4.4 4.4 out of 5 stars (247) |
| Is Discontinued By Manufacturer | No |
| Item Weight | 1.05 pounds |
| Manufacturer | Grodan |
| Package Dimensions | 11.9 x 8 x 4 inches |
T**M
best 4x4 veg cubes!!
Good quality as usual with Grodan cubes, had excellent results for a 3 week veg.
F**H
If you're in the know, it's the way to go.
These are great. Plants grow like crazy in rockwool. The Dutch refined indoor cultivation to an art. The only reasons for bad reviews are whining about price, not understanding that it's a pack of 6, and not knowing how to use the cubes.
J**A
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Genuine Grodan. Nice price and quality stonewool.
M**D
Too expensive
too expensive long delivery rough shape at delivery Not in a box blocks are still usable and not to bad of shape and other than cost they were what I was expecting..
L**E
Best for rooting any thing
I always use Grodan 4" cubes to start my seedlings. Every thing just grows so much better. I also use the round plugs.
J**S
Love
Great item at a good price, fast shipping
J**N
loved it
great product just wish it cost a little less is all
T**E
Expensive for a package full of crumbs upon delivery.
Very expensive for how many you get. Upon arrival the entire package was a mess of crumbles as the rockwool "GRO-Blocks" were all smashed up. Specifically because of the outrageous cost and the extremely poor shape they arrived in, I have decided to no longer use rock wool, even though it is a great product to use in hydroponic gardening. Do NOT recommend this product, at least not from this manufacturer.
Trustpilot
3 weeks ago
5 days ago