Grow Mediums: What's Best For Your Plants

How many times have you heard that growing in soil is better than hydroponics? Or that hydro is better than growing in soil? Or that coco core is superior or clay pebbles?

Growers will stick behind whatever gets them the best yields and before we go taking sides, we think it’s important to learn everything we can about grow mediums so we can make the best decisions for our plants.

In this article, we’re going to be going over a few popular grow mediums and their benefits- including clone and seeding mediums- and how they transplant into other mediums. Planting your garden in the right medium will make the difference between a thriving grow and a grow that barely hangs on until harvest, so we’re going to show you what’s what and let can decide what’s best for your plants. First, let's start with seed and clone mediums.

Rockwool vs. Starter Cells

Ah, the old rockwool vs. start cell debate. There are plenty of ways to start a clone or a seedling growing, but the most common techniques are using either rockwool cubes or rooting plugs.


Rockwool vs Starter Cells
Rockwool cubes are molten rocks that are heated to around 1600 degrees and blown with steam to create a fiber. This fiber creates the network needed for your clone or seedlings’ roots to travel through. They allow for higher amounts of airflow than other types of mediums, which will stimulate root growth better than most mediums.


However, rockwool is naturally high in pH, so when you soak your rockwool cubes you’ll need to check the pH and adjust right away. Otherwise, your pH levels will eliminate those baby plants in no time.

Rooting plugs are made of organic materials mixed and bound together. These are the most natural mediums for your clones and seedlings, and hold in plenty of water while promoting root growth.

However, you should be careful not to over-feed rooting plugs because if you think over-feeding your large plants is bad, you can’t imagine what over-feeding will do to your baby plants. Rooting plugs are more prone to root diseases because they can retain so much moisture, so if you’re going to use rooting plugs keep an eye on how often you feed them.

When your clones or seedlings are fully grown and are ready to transplant, we recommend rockwool going into clay pebbles or any loose hydroponic mediums. If you’re going with starter plugs, we suggest transplanting into soil, as your clones are already used to growing in a soil-like medium.

Soil Grown Plants

Growing in soil can be challenging at times, but for the most part, it’s the simplest medium to grow with. It’s far more forgiving than hydroponic mediums, and the great thing is if you have experience planting a seed in dirt and growing anything you’ve already got experience!

Small seedlings in soil

Unlike hydro where you’re constantly checking the pH and PPM levels in your reservoir water, soil usually only needs to be checked before feeding. As long as the nutrient-rich water’s levels are fine you only have to check them before you feed. However, where people go wrong is in the feeding of your plants- or rather, the overfeeding of your plants.

Soil doesn’t drain or recirculate like hydro, so if you overfeed your plants its roots may not be able to soak up all the nutrients you’re giving it. If that occurs one of two things can happen: the soil could become compacted and won’t allow water to drain down to the roots, or you’ll develop moldy roots that could cause root rot or damage.

Pest Issues- Growing in soil is also going to take a little more time to manage, as well. Pests are attracted to dirt, and soil gardens often have more bug problems than hydro grows. Yields aren’t as quick as with hydroponics, either, taking almost a month or longer to produce the same results. But despite its drawbacks, soil growing is the most natural way to grow your plants and pretty simple if you’ve got the time.

Growing Plants with Coco Coir

Using coco coir in your grow can be a little tricky since it’s relatively new on the growing scene. Though there’s not a ton of info out there at the moment about coco coir and how to use it, growers have seen that using it is similar to growing with soil- if not a little better!

The great thing about coir is that it can be used as its stand-alone medium, or you can use it with soil to help aerate the soil. On its own, you would use it just like you would soil: add a little perlite to the mix, add nutrients to your water, balance the water, plant your plants, and water. The great thing coco coir has over soil is that coir can hold more oxygen than soil, which will help prevent over or underfeeding of your plants.

Plants in coco coir

The Best of Both Worlds- What growers are saying is the best part of using coco coir is that you can essentially get hydroponic benefits in a soil setting. Water travels through coco coir pretty quickly, which means water will naturally fall on to the roots instead of the roots searching for water (like in soil). That means you’ll usually get faster harvests.

But it does come with its own sets of challenges. Most coir comes in bricks, so you’ll need to soak them to break them down, meaning you’ll be doing more than simply adding perlite.

For some reason, coir grows also need a Cal-Mag supplement added to their regimen to ensure your plants get the calcium they need. That may be because coir doesn’t have any real nutritional value, so you’ll need to start your nutrient regimen right away (which might e tricky, seeing as most nutrients tell you how to measure for soil or hydro, not coir)

Growing with Clay Pellets and Pebbles

Clay pellets: a staple in nearly any hydroponic grow you’ve ever seen. If a garden is grown with hydroponics, you can bet its plants will be surrounded by pellets of clay. This is a popular medium for transplanting clones grown in rockwool, as roots are used to having an abundance of water available to them.

Clay pellets allow your nutrient-rich water to flow directly down to your plant's roots so that they don’t have to search for water, like in soil. You can also get better root coverage with clay pellets because water will roll around and wall down on to the roots rather than sinking directly into the soil, where it could be soaked up before spreading out.

The Only Reusable Medium- Pebbles are reusable which makes them worth the investment over soil and even coco coir (which you’ll eventually need to throw out). You just have to make sure to wash them before using them in a new grow.

Note: Clay pebbles can carry harmful bacteria and nutrient imperfections that can affect your grow in a bad way.

The biggest challenge with pebbles and pellets- as with any hydroponic medium- is assuring you don’t overfeed your plants. Overfeeding soil can lead to nutrient lockout, but overwatering your hydroponic plants can kill them pretty quickly. With pellets there is little to no room for error, so if you’re using them make sure you've got some hydro experience under your belt.

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