This All-Star Seaweed Fertilizer Can Be Used for Many Plants 

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Liquid Seaweed Fertilizer

Do you struggle to grow your garden or indoor plants despite all the love, attention, and expensive products you use? 

Vary of using more chemical-filled artificial fertilizers? 

 Looking for a product that will stimulate your plants beyond basic fertilizer? 

Why not try liquid seaweed fertilizer? 

It’s all-natural, harvested sustainably, and fast-acting.  

Better still, it benefits your plants and microorganisms without changing your soil’s pH levels or salt balance. 


Here’s everything you need to know about liquid seaweed fertilizers. 

Is Liquid Seaweed A Good Fertilizer? 

Yes, absolutely! 

Liquid seaweed fertilizers are rich in phytohormones like Cytokinins, Auxins, Betaines, and Gibberellins that are responsible for overall plant health.  

Since the plants sprayed with liquid seaweed fertilizer don’t have to produce these hormones, it means they can utilize energy to grow instead.  

So, not only will your plants grow faster, seed germination and budding will also receive a boost.  

In addition, these same phytohormones prevent the growth of harmful fungi in the soil, thereby promoting plant health.  

Seaweed is also beneficial to plants as it is rich in iron, magnesium, potassium, phosphorus, zinc, and nitrogen.  

These are important nutrients as they promote fruit and flower production and support the development of stronger root systems in plants. 

With over 60 vitamins, minerals, and enzymes in each spritz of liquid seaweed fertilizer, your plants will be stronger, healthier, and disease-resistant. 

Is Seaweed Fertilizer Organic? 

Yes, seaweed is 100% organic fertilizer that is produced by the processing of seaweed available from the ocean.  

Not only is seaweed natural, but it is also sustainable as it can be easily harvested without causing damage to the environment. It is a great source of nourishment for your plants. 

Can You Put Seaweed Straight On The Garden? 

Yes, absolutely!  

Liquid seaweed fertilizer is best used as a foliar spray as plant leaves can easily absorb it. Another advantage to using seaweed straight on your plants is that it deters insects.   

Since liquid seaweed fertilizer contains alginic acid, it helps soil retain water. Alginic acid also helps condition the soil.  

 If you’re having trouble with pH level, poor draining, or soil structure, a little liquid seaweed fertilizer can help.  

The acid also binds with metal particles in the soil, increasing their size. This allows for better air and water movement within the soil.  

So if you’ve got dry patches, use liquid seaweed fertilizer for lawns to improve grass quality. 

If you’ve got plant beds that need a little boost, liquid seaweed fertilizer will be beneficial as it is rich in calcium and iodine and can provide nutrition directly to your plant beds. 

The best part is that microorganisms in seaweed fertilizer release a sticky substance that binds nutrients and prevents them from being washed deep into the ground.  

 They’ll always be present in the top layer of the soil where plants with short roots can access them. 

Don’t have an outside garden? Have indoor plants instead?

Wondering, “Is liquid seaweed good for indoor plants?”

The answer is yes.  

Indoor plants benefit from fertilizer application, just like outdoor plants. And liquid seaweed fertilizer will help promote health, vigor, and structure of indoor plants too.  

Since potting soil has a limited number of microorganisms, which can die from over or underwatering, your indoor plants will benefit from liquid seaweed fertilizer’s soil conditioning and microorganism boost. 

What Plants Benefit From Seaweed Fertilizer? 

If you have a vegetable garden, then potatoes, tomatoes, sweet corn, peppers, oranges, apples, and strawberries, to name a few, will thrive from seaweed fertilizer. 

If you have plant beds overflowing with seasonal flowering plants, spritz some liquid seaweed fertilizer on them.  

All flowering plants, especially geraniums and gladioli, love liquid seaweed fertilizer. 

 Not only will you have more blooms per plant, but your flowers will also be bigger, more brightly colored, and sweet-smelling. 

How Do You Use Liquid Seaweed For Plants? 

Gardening enthusiasts must dilute commercially available fertilizer as per the requirement as the product is highly concentrated.  

The standard ratio for fertilizer to water is 1:50 parts, which roughly boils down to about 4-5 tablespoons per gallon of water.  

For houseplants, you may need the concentration to be stronger.  

Please always check the manufacturer’s recommendations before use. Too much of a good thing does cancel benefits. 
The actual application of liquid seaweed fertilizer isn’t very complicated—all you have to do is mix and use. 

  • If you have a lawn or front yard to cover, prepare a larger amount of solution and use a sprayer.  
  • For indoor plants, pour the prepared mixture in a spray or mist bottle and spritz directly on your plants. 
  • Studies have shown that seaweed extract increases the rate of germination of seeds when used at a lower concentration, if you’re just starting on your garden or seasonal plants, prep your seeds with a little liquid seaweed fertilizer. 

When To Use Liquid Seaweed Fertilizer

While how to use is important, when to use fertilizer is just as crucial.  

After all, giving your plants a growth boost during their dormant stage, especially during winter, will do more harm than good.  

Not sure when is the right time to fertilize your plants?  

Remember to fertilize shortly after the last day of frost—it’s when your plants are shaking off their winter slumber and preparing for growth. 

Other great times to use liquid seaweed fertilizer include: 

  • Before planting seeds 
  • Before cutting flowers for your home 
  • Before repotting plants 
You can collect seaweed from the beach for free

Liquid Seaweed Fertilizer & NPK  

What Is NPK? 

(N) nitrogen, (P) Phosphorous, and (K) Potassium are essential nutrients for plants. These are the primary nutrients without which plants cannot survive.  

N-P-K helps plants store and utilize energy efficiently, resist disease, build better root systems, and produce more flowers and fruits. 

Why Is It Important? 

Commercial fertilizer always contains N-P-K, albeit in varying proportions.  

It is crucial to understand this – if the numbers in the series are higher, it means the more concentrated the nutrient is in the fertilizer.  

For instance, if the product is listed as 20-9-7, it has four times more nitrogen than phosphorus and potassium. 

Understanding these and learning how to read N-P-K values will help you determine which fertilizer is good for your plants.  

Of course, it helps to first identify what nutrient deficiency your plants are facing. 

 Leaves turning yellow, purple, or bronze, spindly plants, stunted growth, interveinal scorching, etc., are some indications of NPK deficiency. 

Does Liquid Seaweed Have NPK? 

Yes, liquid seaweed has N-P-K. However, the N-P-K quantities are lower than commercial fertilizers.  

That is no reason to discard liquid seaweed in favor of commercial fertilizers.  

Why? Because nutrients from commercial fertilizers aren’t as readily available to your plants after application.  

And that means some will get lost, and some will get washed away or go deep into the ground (leaching) where your plants can’t get to them.

And since liquid seaweed doesn’t have any of these issues, it is a “complete” fertilizer. 

Want to give it a try, but not sure where to get liquid seaweed fertilizer?

That’s an easy answer. You can choose to visit your local retail store or even buy it from Amazon. 

What Is The Best Organic Liquid Fertilizer? 

To make sure your garden gets the best it deserves, I did some research and rounded up some of the best fertilizers available for you. 

1. Neptune’s Harvest Fish & Seaweed Fertilizer – Best Liquid Fertilizer  

Neptune’s Harvest is a combination of both fish and seaweed, making it a great product. 

I prefer the brand as it is all-natural and organic. It has an N-P-K ratio of 2-3-1, which is great since I have a lot of flowering plants.  

It’s available online for a modest cost.
You only need a tablespoon of it for indoor plants and 1/8th a cup for everything else lawns, raised vegetable beds, etc. 

2. Blue Planet Nutrients Liquid Seaweed for Plants 

Blue Planet Nutrients’ product is all organic, with an N-P-K ratio of 3-2-1. It’s specifically formulated to boost nutrition for plants in soil-less mediums.

Per gallon, this liquid seaweed fertilizer has a reasonable price, you can check the current price on amazon here  

Aside from these, you can check out other top-rated brands such as Bloom City, Seaweed Bliss, Epsoma Organic Kelp, and Organic Dews, just remember to understand what your plants need and match their requirements to the N-P-K ratio before making your purchase.  


If you live close to the sea, you can collect seaweed from the beach and make DIY fertilizer at home.  

This can be used directly as garden mulch that will gradually break down, supplying essential nutrients to the soil. It is great when mixed with other fertilizers and micro-organisms. 

And if you’re not beach-side, check out the recommendations shared above, or simply browse online for liquid seaweed fertilizer available in your area. 
So, what are you waiting for? It’s time to give your plants a “sea makeover!”