Whether you are growing in soil or hydroponically, there are a number of grow media available to you. Certain growing mediums will suit your needs better than other, and it can be tough to choose one.
The reality is, many forms of grow media can work for you, but there are definitely some that won't. Knowing which one is optimal for your growing environment can make your break your grow.
What is growing media?
The growing media, or medium, is responsible for anchoring your plants in their pot or container. Some growing mediums will provide roots with nourishment, such as soil, while others are completely inert, such as rockwool.
What is the most common type of growing media?
A growing media can be anything these days. People have had success with tactics such as cultivating in newspapers, gravel, and other things you would never have guessed.
For high-quality cultivation, you should stick to one of the traditional grow media options.
What are some common types of growing medium used for rooting cuttings?
While you can certainly cultivate seedlings or clones in traditional soil or one of the other options, this is not ideal. There are specific growing mediums for seedlings and cuttings, such as root plugs or rockwool starting cubes.
The cool thing about these is that as your clone or seedling sprouts and hardens off, they can be planted into a new growing medium without transplanting. These will degrade on their own in a safe and timely matter.
Soil is as simple as growing mediums get. It’s a natural grow media with most of the elements you need to grow healthy plants.
In your soil, you will often find peat, sand, vermiculite or perlite, and sometimes even mycorrhizae for root enhancement. Garden soil contains nutrients that plants can start consuming immediately, unlike inert media such as coco.
Soil is often heavier than other media, because it compacts pretty densely. Growing in soil presents the opportunity for you to grow organically. You can also add certain soil amendments to improve conditions even further.
Best for: Beginners
Soil acts as a buffer, shielding plants from over or under applying nutrients to your plants. Soil will also retain moisture longer, allowing you to water less frequently. It is also more forgiving to water adjustments.
Coco coir is quickly becoming one of the most popular media to grow in. This growing medium retains moisture well, allow roots to breathe, and provide a good support structure.
There are many names for coco such as coir, coconut fiber, coco peat, and coco husks.
Soilless mixes are a balanced growing medium. Often times, a soilless mix will consist of coco coir, perlite, and other organic compounds. Coco will make up the bulk of this mix, up to 50% usually.
Using a soilless mix is one of the best ways to cultivate plants. You are providing your plants with tons of natural compounds to jump start their life.
They are very similar, but vary slightly in size and the exact location on the coconut that they are taken from. Higher quality coco husk is is pH balanced, and treated to remove salts.
Best for: Intermediate to advanced
Coco offers great aeration and moisture retention but does require you to make sure it is pH neutral.
Clay pebbles and growstones are great for hydroponic systems since they support the plant while allowing roots access to nutrients, water, and air.
Also known as hydroton, and sometimes called lightweight expanded clay aggregate (LECA), this is a traditional media for hydroponic setups. They offer good drainage and are pH neutral. Many growstones are pH neutral or will become pH neutral once soaked in a pH balanced solution prior to use.
Growstones are made from recycled glass, and are extremely porous. If properly cleaned and sterilized, they can be reused between growing cycles. One of the benefits of their porous nature is that it forces roots to shoot off in more directions creating a denser root mass.
To learn more about the difference between clay pebbles and growstones, check out this guide.
Best for: Advanced
Clay and growstones require constant watering. These are best suited for a grow system that will provide constant liquid nutrients directly to the roots of plants while still allowing them access to oxygen, such as hydroponics.
Rockwool has many hydroponic friendly qualities, such as being able to retain moisture well while providing good root aeration.
Rockwool maintains well throughout the growing cycle. This is important in hydroponic systems where grow media might clog or damage water pumps and equipment. It can be used from germination to harvest, making it an all around excellent grow media.
Best for: Intermediate
Rockwool requires a continual application of water and nutrients to plant roots. It retains moisture well, but should only be moist, not damp (think a rung out sponge).
Perlite is lightweight and porous, and can be used on its own or in combination with other grow media. Featuing a long life-span, perlite is easily renewable. Perlite offers good water retention, aeration and drainage. It has a natural pH of 7, making it a neutral growth medium. The porous nature of perlite makes it a good temperature insulator for roots.
Best for: Beginner - Advanced
When used with other soil or soilless media, its a great amendment for beginners. When used alone it should be in a grow system that will continually water roots and provide nutrients in solution.
Amendments can add nutrition, stability, or drainage benefits depending on what you choose.
You can augment your grow media by adding nutrients or additives to emphasize specific traits of characteristics of your plant that make it appealing to you.
For the organic grower, look for the OMRI Certified label on products to ensure that you are organically growing from germination to harvest. Common amendments include:
Bone Meal: Great for a slow release of phosphorus and protein.
Blood Meal: Excellent source of nitrogen and is often used as a composting activator.
Kelp: Promotes cell division and growth in plants.
Bat Guano: Contains high levels of nitrogen, phosphate, and potassium.
Seabird Guano: Contains higher levels of nitrogen, phosphate, and potassium than bat guano.
Perlite: Contains high levels of silicon dioxide and aids in aeration and filtration. Acts as an alternative to diatomaceous earth to deter insects and pests.
Mycorrhizae: Forms a symbiotic relationship with plant roots to promote growth and sugar/water/mineral exchange.
Worm Castings: Improves aeration of soil and enriches with micro-organisms. Attracts deep burrowing earthworms already in the soil and improves water retention.
Humic Acid / Hummus: Increases update of nutrients and can filter some toxins
Click here for our full guide on organic dry amendments!
Best for: Beginner - Advanced
Amendments are a great way to specifically target characteristics of your gardening and dial them in. Beginners can get experience with different additives and how they affect their plants. Advanced growers can emphasize specific traits of their plants that they wish to highlight.
If you have a need for bulk grow media, Hydrobuilder has a great supply that can meet any of your needs no matter how large. Buying in bulk is a great way to take advantage of volume discounts and unique shipping offers. Call us at 888-815-9763 for a custom quote on any large or bulk purchase. Bulk media can be black wrapped for security and discretion, and often comes in pallets.
Best for: Intermediate - Advanced
We recommend that you call us for a custom quote anytime you are considering buying bulk so we can save you money.
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Our commercial customers get special pricing, and the assistance of an expert grower throughout their grow.
Questions? Call us at 888-815-9763 or email firstname.lastname@example.org.