How To Clone Plants Using Rockwool - Happy Hydro

If you love your green thumb and have been wanting to learn how to clone plants, then this guide is for you! Cloning plants may sound daunting, but it's pretty easy - especially when using Rockwool. Rockwool is a growing medium made from spun basalt rock commonly used for hydroponics.  Rockwool provides an ideal environment for roots to thrive when it comes to cloning plants. Plus, it's easy to use and relatively inexpensive. Here's everything you need to know about cloning plants using Rockwool.

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Getting Started

To get started, you'll need the following supplies:

  • Rockwool cubes or slab
  • Plant cuttings (about 4-6 inches long)
  • Rooting hormone powder or gel 
  • Weakened nutrient solution
  • Sharp knife or scissors (sterilized)
  • Clear plastic cover (optional)

Once your supplies are gathered, sterilize your scissors/knife and it's time to take your plant cuttings.

Taking Cuttings for Clones

It's best to take cuttings from healthy, mature plants currently in veg. To do this, snip off a 4-6 inch section of stem with a sharp knife or scissors. Make your cut below a leaf node (the point on the stem where leaves branch out). Once you have your cutting, immediately dip the end into the rooting hormone. This will help encourage root growth.

As Rockwool is sterile and inert, which makes it an excellent medium, consideration for feeding/nutrients will need to be accounted for. Unlike seeds, which have stored nutrients within the seed itself, unrooted clones will need to start feeding as soon as possible. A weakened nutrient solution or specially formulated cloning solution will help the plant to root and begin new growth.

Preparing Rockwool & Rooting

Next, it's time to prepare your Rockwool. If you're using cubes, simply soak them in water or cloning solution for about 10 minutes until they're fully saturated. If you're using a slab, you'll need to cut it into smaller pieces that will fit into your propagator or growing tray. Once your Rockwool is ready, gently insert your plant cutting halfway into the medium. Make sure the hormone-coated end is pointing downwards. Repeat this process until all of your cuttings are in Rockwool.

Place the lid on top of your container to create a mini greenhouse effect if you're using a propagator or growing tray with a clear lid. This will help maintain humidity and prevent your cuttings from drying out. If you're not using a cover, simply mist your cuttings daily with water to keep them moist. Place your container in an area that receives indirect sunlight and wait for roots to form. This can take anywhere from 7-14 days. Once roots have started, you can transplant your cloned plants into pots filled with potting mix or a hydroponic system.

Author | Chris McDonald

With two decades of expertise, Chris leads Happy Hydro in redefining sustainable gardening and delights in backpacking adventures, mind-expanding journeys, and creating memories with his loved ones.

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