The use of high-quality nutrient sources is key during the cannabis grow cycle. Keeping an accurate flow of nutrition into the soil of your plants will ensure maximum health, vitality, and yield. It will mean that you avoid the risk of your plants encountering deficiencies, which will wind up damaging their health, slowing their growth, and reducing the prized end result of the harvest.

There are numerous options to select when it comes to nutrients for your crops, from waste food items all the way to commercial product lines. Well, we want to introduce the idea of using a unique yet effective choice of nutrients: seaweed.

As it happens, seaweed is absolutely crammed with beneficial nutrients that your cannabis plants will happily utilise to achieve optimum health, size, and growth. Seaweed is available to growers in numerous forms. The first form is easily the cheapest and most accessible for those who live near the coast. We’re talking about fresh seaweed, which can simply be harvested during a trip to the beach.


Many different types of seaweed have been employed all over the world for centuries in agricultural settings. Fresh seaweed contains a plethora of major and minor plant nutrients and trace minerals that it absorbs from the ocean. These include minerals such as sulphur, magnesium, boron, and calcium.

When ground up and incorporated into meal, seaweed may also contain beneficial vitamins such as A, C, B12, K, and E. Seaweed also contains substances that regulate plant growth, contributing to rapid and explosive development of crops.

Seaweed also helps soil to retain moisture and may reduce the amount you have to water your plants. When used as a mulch, seaweed may also reduce or eliminate the need to weed your garden, acting as barrier against the formation of intrusive plants.

It’s not only weeds that seaweed offers defence against; the lifeform also produces compounds that are effective against certain fungi, viruses, and bacteria. It’s almost like a medicine for your cannabis plants. As well as fighting off bad bacteria, seaweed can help to condition the soil and encourage the growth of beneficial bacteria.

Seaweed As A Fertilizer Of Soil For Organic Cultivation


Considering you live relatively close to the ocean, the easiest way to obtain seaweed is to forage it for yourself. This eliminates any cost and is a perfect chance to go and immerse yourself in nature for a while.

Before you do so though, it’s worth doing some quick research into the area you plan to forage at. Taking seaweed from a polluted area is not advised, as this may introduce undesirable substances into your garden. It’s also worth checking if there are any restrictions in place that prohibit taking seaweed from the local environment.

If you’re in the clear, head to the beach with a bag and collect a bounty. Use a species guide to identify what you take. Kelp is a very popular choice among gardeners, along with knotted wrack.

Once harvested, head home and give your bounty a wash. Next, it’s time to decide what to do with it.


Most seaweeds can be directly applied to the soil via mulching and will break down quite fast. Simply layer seaweed over the top of your soil and let nature takes its course.


Given all of the nutritional benefits, it's quite obvious that seaweed will make an excellent addition to any compost bin. Be sure to mix in the seaweed well with the rest of the materials to prevent any slime from reducing airflow.


Liquid fertiliser is very easy to make and extremely easy to apply to plants. It can also be made highly concentrated, so less volume needs to be used at a time. Simply add your seaweed and other composting material into a barrel with a small amount of water, and wait for it to break down over the course of several months.

Once ready, it can be sprayed onto your crops to help defend against disease and to assist during the flowering phase.

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