Why We Love Rockwool
Rockwool is one of favorite ways of growing anything. Rockwool originally started out in commercial growing applications, specifically with hydroponic growers. However, in recent years as home hydroponic and growing has become more popular we are seeing more and more people using Rockwool plugs.
So what is Rockwool?
Rockwool is exactly what it sounds like. Rockwool is made by taking molten rock/sand and spinning it, similar to when you make cotton candy. The end result is a dense wool like product that is inert, has no mineral, and is great at soaking up water and remaining saturated, but not too saturated.
Rockwool comes in a variety of sizes, ranging in small plugs perfect for starting seeds and propagating cuttings, all the way up large slabs which can be used for larger plants.
Why is Rockwool such a great product to use?
Rockwool is dummy proof and unlike using soil, Rockwool is almost impossible to over saturate thus increasing your chances of seed germination and reducing your chances of root rot.
Further to the above, Rockwool is super cheap and if you really wanted to you can even re-use your Rockwool plugs after your harvest.
The only downfall about Rockwool plugs is the need for frequent nutrient applications. Rockwool has no major nutrients in comparison to seed starting soil or potting mix which usually has slow releasing nutrients for up to 6 months.
How to use Rockwool
- Soak your Rockwool plugs for 10 to 20 min. Before you use your Rockwool plugs or slabs you will want to give them a good cleaning. This is not mandatory, but, is a good practice.
- Once your Rockwool plugs are cleaned place them in a hydroponic grow cup or in your growing bed. Note: I prefer to use expanded clay pellets for my growing bed.
- Insert your seeds or cuttings into your Rockwool plugs.
- Watering should be done every 4 hours, but this is dependent on the type of plants you are growing as well as other conditions such as temperature. The rule of thumb is to ensure that your grow beds water limit is slightly below the bottom of your Rockwool plug. This will ensure that the Rockwool does not wick water upwards and remain soaked 24/7.
If you choose not to grow hydroponically, you can also use your Rockwool plugs as seed and cutting starters. As long as you keep the Rockwool moist, you can fully root cuttings and start seeds. A few weeks after germination, you can place the plugs directly into a garden or soil filled container. The Rockwool is porous enough that the roots of your growing plants will slowly punch through it and into the soil.
If you ever grow lettuce you should use Rockwool plugs. You can thank us latter! I have never had so much success growing lettuce until I stared using Rockwool plugs.
If you have any questions about this post or about using Rockwool growing products feel free to leave them in the comment section below.