Rapid Rooter vs Rockwool: Which is the Better Growing Medium?

It is no secret that growing medium is the foundation of any Plant growth success. When a grower puts a seed in any growing medium, he knows that even after following every recommendation, if this medium is not good, seed germination won’t take place. The two famous growing media are rapid rooters and Rockwool. To know which one is better for you, we have made Rapid Rooter vs Rockwool comparison. This comparison will help you in better understanding how you can do successful gardening

Growing media are of two types- one is sold by keeping in view the weight and the other is sold as a whole cube or cylinder. This cube or cylinder is known as a Starter plug. Both rapid rooter and Rockwool are starter plugs. Let’s formally introduce you to Rapid Rooter.

Rapid rooter Is a starter plug that is used in indoor gardening especially in hydroponics. It is made by General Hydroponics. There are 50 plugs in one bag. The rooters are:

Rapid Rooter

  • 1.5 pounds in weight
  • 10.5 inches in length
  • 12-inch in width
  • 3.5 inch in height

Want to know what are rapid rooters made of? Sphagnum Peat moss and a binder are used to make rapid rooters. Thus, Rapid rooter plugs are compact and don’t get loose or break apart.

Rapid Rooter vs Rockwool
Rapid Rooter Image

Due to compact rapid rooter plugs, the growing process is super fast and easy. Moreover, there are no complications when you use rapid rooters for seeds’ germinations.

Simply, put a rapid rooter plug out of the package and sow the seed in it. After some time, you will see seedling emerging along with the tap root.

You can also use this plug to grow clones and sensitive plants. For cloning, just cut it apart from the mother plant and plant it in the growing media.

Rapid Rooter Instructions: How to use it?

Rapid rooter plugs can be used in both soil and soilless system. Let’s have a look at how you can grow using rapid rooter plugs:

1) First of all, take out rapid rooter plugs from the bad and add pure water or nutrient solution. This hydration is necessary for the smooth germination of plants. If the plugs are already wet, then you can skip with the hydration.

Rapid Rooter is not a nutrient-rich medium. It is made up of peat moss which is not much nutritious. So, to meet up the nutrient requirement, you must add nutrient solution before sowing of seed. Here’s how you can do it:

a) Take a big container or tray where you can fit the rapid rooter plugs easily.

b) Then add nutrient solution to the level that every plug will receive the solution. Soak them from one hour to a day.

2) There will be a pre-made hole on the rapid rooter plugs. Put seed or cutting in those holes.

3) Every two to three days, pour 16 ounces of pure water into the rapid rooter tray.  

4) Lighting sources such as fluorescent bulbs or any other grow light should be placed six inches above the rapid rooter tray.

5) The micronutrients and excellent aeration capacity of this rooter lead to robust root growth. Rooted cuttings will become just like the mother plant.

After roots emergence, transplant the rapid rooter plugs into the hydroponic system or any other system.

Rapid rooter plugs need pots, cups, or something like that to hold them. The rooters can’t stand on their own and definitely needs some support. You can put each rooter into the net pot and then place the net pot at an appropriate location according to the system.

After knowing about Rapid rooter, it is time for you to know about Rockwool.


Rockwool is a wool-like material that is made after melting basalt rock and then spinning it into fibers. These fibers are shaped into cubes where you can sow seeds or plant cuttings.

Rapid Rooter vs Rockwool

Rockwool is carefully made and even sterilization is done to get rid of any weed or pathogen. Thus, Rockwool does not contain any harmful chemicals that may harm the plants. However, some humans may feel skin irritation after touching the cube.

The cubes of Rockwool have decent drainage properties and soil aeration. Oxygen and moisture level is optimum in them. But there are some concerns about them that make a grower wonder whether he/she should use Rockwool cubes or not. Rockwool cubes have no nutrients in them. So, the nutrient solution must be applied for smooth plant growth. Moreover, these cubes are not biodegradable, so they’re not considered eco-friendly either.

How to use it?

Let’s have a look at how you can effectively use Rockwool to grow Top quality plants.

1) Rockwool has a high pH ranging between 7-8. So, put the cube in the slightly acidic solution for about half an hour. You can use pH up by General hydroponics or you can yourself make a slightly acidic solution using lemon juice and then check it with pH strips.

2) Then put the seeds in the hole present on top of the Rockwool. If you are cloning, then cut the mother plant part, and dip it in the rooting hormone. Then put it in the Rockwool. You will see it growing roots after a few days.

3) When the roots start to emerge, you can transplant them to soil or the hydroponic system.

Rapid Rooter vs Rockwool
The seedling grows after transplanting into the soil.

Now, let’s have a look at Rapid Rooter vs Rockwool comparison.

Rapid Rooter vs Rockwool

Let’s compare them by analyzing their similarities and differences.

Rapid Rooter vs Rockwool: The Similarities

The similarities between the two growing media are:

  • Both Rapid rooter and Rockwool are starter plugs in which you can sow seeds or put cuttings.
  • Both starter plugs can be used in soil and soilless systems.
  • When you compare rapid rooter vs Rockwool germination (of seeds), then both provide ideal conditions for seeds to sprout.

Rapid Rooter vs Rockwool: The Differences

These are the Rockwool cubes vs rapid rooter plugs differences:

Rapid RooterRockwool
Neutral pHSlightly basic (alkaline)
Made up of Peat mossMade up of rock
Expensive than RockwoolCheap
Excellent water retention abilityWater retention is good
BiodegradableNot Biodegradable
Rapid Rooter vs Rockwool

After looking at the comparison, Rapid rooter seems to be the better choice. It has neutral pH, contains some nutrients of its own, and is also biodegradable. But that doesn’t mean Rockwool is not good. Rockwool has shown tremendous results and you can get a high yield if you do everything right. But its slightly alkaline nature and non-decomposing character make it a little less desirable than rapid rooter. However, it is cheap, so you can use it if you have a low budget.

Let’s have a look at some other Rapid rooters alternatives you can use!

Rapid Rooter Alternatives

If for some reason rapid rooter is not available, then you should go for its suitable alternative. Rapid rooters’ alternatives are Jiffy Pellets, Oasis Horticubes, and a variety of other soilless mixes.

Jiffy Peat Pellet

Jiffy Peat pellet is either made up of peat moss or coco coir. The key features of this product are:

  • This growing media is super effective in minimizing the transplant shock and any sort of root damage
  • Due to better aeration, root development is easy and fast
  • Due to its low volume, it is easy to transport and store.
  • They are very similar to the rooters with few differences.
Rapid Rooters vs Jiffy Pellet
Jiffy Peat Pellet Image

Let’s have rapid rooters vs peat pellets comparison.

Rapid Rooters vs Jiffy Pellet

Rapid RooterJiffy Peat Pellet
Held together by the binding form which is invisibleHelf together with plastic
Bio-degradablePlastic in it is not degradable
Rapid rooters vs Peat pellets


Horticubes is a growing medium that is foamy in composition and is specifically used in hydroponics. If you use this medium, then you will witness the smooth seed germination of vegetables and herbs. The key features of this product are:

  • It is an excellent addition in hydroponics as it still provides air even if you add excess water.
  • The drainage is also good in this medium which causes the top surface to remain considerably dry and only the root zone will have moisture. This reduces the growth of Algae and plant will grow out to be healthy and of top quality.
  • It does not cause harm to harm or humans. You don’t even have to wear gloves for protection while holding it. Moreover, it is sterilized, so there are no chances of any pathogens and diseases.
Horticubes vs Rapid rooter

Let’s compare it with Rapid rooter:

Horticubes vs Rapid rooter

Rapid RooterHorticubes
They can be used in soil or soil-less systems. It is specifically designed for hydroponics systems only
You can grow many types of crops with the help of the rooters.Only vegetables and herbs can be grown.

There are some other soil-less mix media that you can also use as an alternative. These are Pro-mix, vermiculite, rice husk, or any other organic material.

Final Words

All-inclusive, a top-quality growing medium is super important for proper plant growth. From seed germination to fruit production, the growing medium has a hand in every plant stage success. The two famous growing media are Rapid rooter and Rockwool. We made a Rapid rooter vs Rockwool comparison to reach a conclusion about which one you should use. Rapid rooter biodegradable and pH neutral characteristics make it the best choice for growing plants.

However, Rockwool is also an excellent option to opt for. It is cheap and has excellent aeration and water retention ability. You can also use Jiffy Pellets or Horticubes as a Rapid rooter alternative. Just follow the recommendations we have described above related to these growing media and enjoy high yield!


Are rapid rooters better than Rockwool?

Yes, rapid rooters are considered better than Rockwool due to two reasons. One is that these are biodegradable, so they are environmentally friendly. The other reason is that the pH of the rapid rooter is neutral. So, you don’t have to add any slightly acidic solution as you do while using Rockwool. But Rockwool is cheaper than rapid rooter. So, if you have low-budget, you can go for Rockwool.

Do rapid rooters decompose?

Yes, rapid rooters are biodegradable and they decompose. This is a great thing for the environment as non-biodegradable plastic is already causing enough damage to the ecosystem already.

Are Rockwool cubes good?

Yes, Rockwool cubes are good in what they do. They have a good water retention capacity and sufficient aeration. Moreover, the cubes are sterilized too, so there are no chances of any pathogens or insects in them. They are also cheap and you can easily buy them online or at any nearby gardening store.

How long do you soak Rapid Rooter?

Take a big container or tray where you can fit the rapid rooters properly. Then add nutrient solution to a level that every rooter receives enough solution. This will make the medium nutritious and will lead to robust growth. Soak the rooters from one hour to a day.

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I am a graduate in Agriculture Sciences and have been doing gardening for over 7 years. I am also a professional and certified Article & Blog Writer. I am happy to share my years of experience in gardening with all of you through my writings. In addition to this, I do extensive research on every topic to enrich readers with valuable knowledge.