Powerfeed vs Seasol: Which to Choose?

When it comes to choosing a fertiliser, there are many great options on the market.

On the face of it, PowerFeed and Seasol look similar, but they have some distinct differences that make them each better suited for certain situations.

We’ll take a look at what these differences are below.

What is Powerfeed?

Powerfeed bottle | Plant care

PowerFeed is a fertiliser made from a base of fish, which then is fortified with a mixture of nitrogen, phosphorus, and potassium – the common 3 elements in garden fertiliser.

These nutrients are available in different quantities depending on the concentration of PowerFeed in water.

The ratio of these 3 elements is expressed as NPK (N = nitrogen, P = phosphorus, and K = potassium).

In Powerfeed, the ratio is N 12%: P 1.4%: K 7%. As you can see, Powerfeed is high in nitrogen and potassium.

Nitrogen promotes vigorous leaf growth and deep greening of plants, but too much can cause the burning of foliage.

Potassium, on the other hand, helps plants withstand stress and promotes overall hardiness and disease resistance, as well as root development and general vigour of plants.

Powerfeed is low on Phosphorus (compared to a balanced 5:5:5 fertiliser), which promotes root growth and flowering.

PowerFeed is also a clay breaker and encourages soil activity. It reduces leaching in sandy soils and helps increase the nutrients available to plants.

What is Seasol?

seasol bottle 3 | Plant care

Seasol is a specially formulated seaweed extract. It’s a mixture of Bull Kelp, Chile Bull Kelp and Knotted Kelp.

Seasol is not, strictly speaking, a fertiliser because it contains only low levels of nitrogen and phosphorus. Seasol can be used as an alternative to other fertilisers, such as nitrogen-based fertilisers.

Seasol is a seaweed-based garden health treatment that contains plant nutrients, trace elements and other bioactive compounds.

By encouraging beneficial soil micro-organisms, this seaweed concentrate promotes healthy roots and stimulates flowering and fruiting

It also improves plants’ resistance to pests, disease, drought and frost.

Powerfeed vs Seasol: What’s the Difference?

Powerfeed is a fertiliser

Aside from their base ingredient (seaweed vs fish), the main difference is that Powerfeed has been fortified with a mixture of nitrogen, phosphorus, and potassium.

These are commonly recognised as the essential components of general-purpose fertiliser.

Seasol, on the other hand, only includes small amounts of nitrogen and phosphorus.

Application times

Seasol, unlike fertilisers, can be applied year-round.

This gives you more flexibility in your application schedule.

Potential burning

Powerfeed, like all fertilisers, begins releasing nutrients when it is applied to the soil and when it is watered.

When granules remain in contact with the trunk or stem or a plant or tree, they may cause some minor burning, which can be a particular risk to young plants.

High-nitrogen fertilisers, in particular, pose this risk.

Therefore, ensure you water immediately after application, and avoid applying fertilisers directly on the main stem or trunk.

Suitability for natives

While the manufacturer does state both products are suitable for natives (look for PowerFeed products with “including Natives” on the label), Seasol contains almost no phosphorous, so it’s safe to use on any plant, including natives.

Many Australian native plants are highly sensitive to an overabundance of phosphorus.

This is because most Australian soils are phosphorus-deficient and our native plants have adapted to live happily in low-phosphorus soils. 

Powerfeed vs Seasol FAQs

What is PowerFeed used for?

Powerfeed fertiliser contains active liquid composts which improve soil structure, boost plant growth, stimulate flowering and fruiting, and help break down clay and reduce nutrient losses in sandy soils.

Is PowerFeed a fertiliser?

Yes, PowerFeed is a fertiliser. It has an NPK ratio of 12:1.4:7, meaning it is high in Nitrogen and Potassium.

Is PowerFeed OK for natives?

Many products in the Powerfeed range are suitable for natives. Look for “including Natives” on the label.

Is PowerFeed good for indoor plants?

Look for the product “PowerFeed 1.25L Ready To Use Indoor And Potted Plants Plant Food”. This fertiliser comes in a handy spray bottle and stimulates adds liquid compost to condition the soil and promotes vigorous plant growth.

What is Seasol good for?

Seasol promotes healthy roots and helps your plants thrive. It encourages beneficial soil micro-organisms; stimulates flowering and fruiting; and helps your plants cope with stresses like heat, drought, frost and pests and diseases.

Can you put too much Seasol on plants?

Seasol is a soil conditioner, not a fertilizer, so it won’t burn your plants or harm them in any way.

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Steve Kropp

Based in Melbourne, Steve's passion is vegetable gardening, and he’s been writing about it for almost 5 years. He also loves all things DIY and is always looking for a new project. When not working on his own garden projects or blogging, Steve enjoys spending time with his family, cooking meals with produce harvested from his garden, and coaching his son’s footy team.


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