Grodan Rockwool Cubes, Indoor Gardening and Seed Starting Usage, (1 inch) 100 Cubes

These 1" cubes can be used as an alternative to the peat-based grow sponges in the Aerogarden Harvest hydroponic system. They are roughly 1/3 the cost. You can easily trim them using scissors to taper the bottoms for a better fit in the Aerogarden grow baskets. The one downside to this is that they will not compost after use like the peat ones do but could still be dug into garden beds where they will eventually break down. They seem to work well but do tend to grow some algae on the top surface, a little more than the peat ones do.

great quality. did everything it’s supposed to!

After researching what to use in my new hydro kit, this came out on top. the sponges that were supplied have not done a thing, while these almost all have great growth. I just ordered more to replace the sponges.

Be careful to use a scissors to separate these from each other. Such instructions were not found in the packaging. Otherwise they rip to shreds if just pulled away from each other. Also, from what i learned on videos, there is no need to close up the rockwool around the seeds. Just leave it open. I did this and my lettuce sprouts are coming up after 2 days with no issues. Note: I would be happier if I could find rockwool that tapers and fits snug into my net cups.

The rockwool arrived on time, but I have serious concerns about the packaging so I had to take off stars. It was entirely unwrapped! Literally just a square of rockwool cubes sitting plain on the floor of the cardboard shipping box! No plastic wrapping, no BRANDING of any kind so who knows if it's even Grodan brand as it claims to be. This is a big problem, guys - these things are meant to stay sterile to grow plants in. They are ABSORBENT. Leaving them unwrapped in a cardboard box means they will soak up every liquid the cardboard box comes in contact with. Rain. Dew from your porch. Road run-off in your driveway. Chemicals from your damp lawn. Not good. Plus, the cardboard box it came in was, well, just a normal cardboard box, which means that there were little holes at the corners. Which means potential for insects, which would just love to lay eggs in something like rockwool. Seriously...the packaging issues are a BIG problem with this kind of product. Next time I'm going to buy directly through the Grodan website, and I highly recommend everyone else does as well.

These are good standard rockwools. Beware that these are the smaller one inch ones and will not fit snugly in the standard 2 inch netcups. The seed hole is also larger than other ones I've bought so the seed planting is quite easy

I bought my product in October of 2024. I am almost positive that what I received is not a Grodan product (unless it came from the dumpsters at the quality control lab). My product came unwrapped in a homemade box sans manufacturer's labeling. The rockwool is poor quality and I experienced the usual issues for poor quality rockwool. The rockwool won't hold together. The holes are too large and won't close over the seeds. Unsure of the actual material used.

I really like the price. I used these last winter for an indoor hydroponic garden. They worked great. They were smaller than I thought, and will be buying larger ones this year. Also, the material felt more brittle compared the spongier feeling materials that I was used to buying in the past.