The UK's premium seaweed fertilizer

High quality, cold pressed British kelp
approved by Organic Farmers and Growers

Summary // In a nutshell

Carefully refined over a period of ten years, this is a premium organic fertilizer for discerning growers. Because when it comes to your plants, we know you don’t want to compromise.

We employ only the finest seaweed from the cleanest Atlantic waters and distil it without heat or chemicals. Then, we wait. Because some things shouldn’t be rushed.

Organic gardening does not have to be complicated: if you use quality products, the results will naturally follow.

  • Pure Ascophyllum nodosum from the North Atlantic coast
  • Unbeatable for vegetables and fruits. And lawns. Oh, and houseplants
  • Grow bigger, greener, higher, fatter. Show up your neighbours
  • Certified organic by OFG. Vegan-friendly. No nasties
  • Created in rural Shropshire. In a barn. One hundred miles from the sea
  • Available in 1, 5, 10 and 20 litre quantities

About // How it works

Seaweeds are some of the quickest growing plants on the planet with some species expanding by several feet in length every day. This growth is driven by the presence of hormones called auxins and cytokinins. Luckily for the gardener or horticulturalist, these active elements can be harnessed for use on practically any plant by using distilled seaweed fertilizer.

Regular application of seaweed fertilizer encourages growth in plants, grass, trees, fruits and vegetables. On top of this, seaweed contains some of the widest variety of macro and micro nutrients in the world which it draws in from its marine environment. These help to provide plants with a range and variety of the nutrients they need to thrive.

Besides the growth stimulants and wide range of nutrients, seaweed has also been shown to have an impact of the health and composition of root zones and boost chlorophyll levels in plants.

"If you can afford only one type of fertiliser make it seaweed." // Alys Fowler, Guardian garden writer

Application // Get the best from your bottle

Mix The Shropshire Seaweed Company Organic Fertilizer with water at the rates given below. Please note that 0.1% is equivalent to 1ml of seaweed in 1l of water. Use as a foliar spray or a root drench, whichever suits the job best. And remember, little and often is the way with seaweed.

Store in a cool place out of direct sunlight. Use within two years of opening for best results.

General rates

Plant Rate Frequency
Vegetables, herbs, chillies, tomatoes, potatoes 0.2 %  Every 10-14 days
Flowers 0.3 % Every 5-7 days
Trees 0.4 % Every 7-10 days
Hedges and Shrubs 0.3 % Every 7 days
Hard and Soft Fruits 0.25 % Every 7 days
Houseplants 0.2 % Every 5-7 days
1ml per square metre,
or 2ml per square for amenity or recovery
0.5 % Every 28 days

"And I'm a great fan of seaweed, and I feed all my containers with a weekly liquid seaweed feed from about June onwards." // Monty Don, BBC Gardeners' World

Seeds and seedlings

Soak your seeds in a weak concentration of The Shropshire Seaweed Company Organic Fertilizer and water (0.1%) for up to 12 hours before sowing. This will boost their germination by up to 80%. When transplanting seedings, dip their roots in a stronger seaweed extract solution (0.2%) to help their roots adjust to their new pot. Once the seedlings are three weeks old, they are ready for their first foliar feed. Again, use the 0.2% mix and mist them all over. Using seaweed at these three crucial stages lays the foundation for healthy and strong plants in the long-term.


Hydroponics is a rapidly expanding sector on the British growing landscape - and here too seaweed extract is a very beneficial supplement. The Shropshire Seaweed Company Organic Fertilizer should be added at a rate of 0.05% every seven days. Combine with a two-weekly foliar spray of the crops themselves at a rate of 0.2%.


The Shropshire Seaweed Company Organic Fertilizer is a low-cost way of keeping the grass in good condition for your animals. It's also totally organic and offers no threat to the health of horses, cows or sheep. You don't even need to clear them out of the field to apply it. Mix 2l of Shropshire Seaweed per acre (or 5l per hectare) and dilute at a rate of 1% with water. Apply evenly across the area once or twice a year for optimum results.


There are a wide range of uses for The Shropshire Seaweed Company Organic Fertilizer in the agricultural sector. Contact us for more information and we can send you a feed schedule based on what you're growing.

Technical Information // What's inside


Seaweed: Ascophyllum nodosum; Appearance: Golden to dark brown; Alginates: c. 30%; Suspended solids: c. 5%; pH: 5.3 to 6.0; Density: c. 1.05g/cm2; Solubility: Complete; Shelf life: 24 months


Macronutrients (%)

Calcium: 1.95; Chlorine: 3.42; Magnesium: 1.23; Nitrogen: 0.62; Phosphorous: 0.12; Potassium: 2.11; Sodium: 3.10; Sulphur: 1.56

Micronutrients (PPM)

Barium: 127; Boron: 194; Copper: 6; Iodine: 1200; Iron: 211; Manganese: 22; Selenium: 4; Zinc: 35

Active Agents

Auxins; Betaines; Cytokinins; Alginic Acid; Mannitol; Lamanarian; 18 Amino Acids; 10+ Vitamins

Buy now // Available in a range of sizes

Head over to our shop to grab your bottle and experience the difference for yourself. The product comes in a size for everyone - from window grower to Percy Thrower.

Get involved // Join our community

Social media

The Shropshire Seaweed Company Facebook and Instagram pages are where our growers can find advice about using the product. It's also where our loyal legion of advocates share their stories and experiences. Give us a follow and join the community.

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Cut the plastic // Refill at dozens of locations

In 2021 we launched our Organic Fertilizer as a refill product. It is part of our efforts to drive down the use of single use plastic. It has been a huge success with customers all around the country taking their used containers to zero waste shops, taking however much fertilizer they need, and paying by the weight.

Check the map below to see whether there is a location near you.

Interested in stocking the product?

If you run a zero waste store in the UK and are interested in stocking this product, please click here.