Cold-pressed seaweed, liquid organic biostimulant
Regular price
$18.00
Regular price
Sale price
$18.00
Unit price
/
per
| Conditionnement | Price | Price per L | vs 500 mL |
|---|---|---|---|
| 500 mL | $18.00 | $36.00 | — |
| 1 L | $29.00 | $29.00 | −19 % |
| 5 L | $121.00 | $24.20 | −33 % |
$6.00 × 3 with no fees
Klarna.
This Ascophyllum nodosum seaweed extract, obtained by cold pressing, is added to irrigation water or nutrient solution during growth, from the first true leaves through to flowering. It is dosed at 5 ml per litre when watering and at 3 ml per litre when spraying the foliage.
It is suitable for use in organic farming, in soil, in coco fibre, and in hydroponics.
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The summary
- What you receive: a 500 ml or 1 L bottle, or a 5 L container, of liquid seaweed extract.
- The dose: 5 ml per litre of irrigation water, or 3 ml per litre as a foliar spray.
- The timing: from the first true leaves through to the end of flowering.
- The material: 100% cold-pressed Ascophyllum nodosum, approved for organic farming.
Liquid seaweed extract for growth, applied as a root drench or foliar spray
Seaweed extracts are among the oldest biostimulants in horticulture: kelp was already being spread on coastal fields long before synthetic fertilisers existed. This product takes that same principle and delivers it in a concentrated liquid form, which you dilute at watering time. It does not replace your fertiliser, as it supplies very little nitrogen, phosphorus or potassium, but it complements it throughout the vegetative growth phase, when the plant is building its roots, stems and foliage.
🌊 A cold-pressed seaweed
The raw material is Ascophyllum nodosum, a brown seaweed from the shores of the North Atlantic, known in Brittany as goémon noir. It is milled and cold-pressed, without heating or chemical hydrolysis, which preserves the compounds that are sensitive to temperature. The resulting liquid contains polysaccharides such as alginic acid and mannitol, trace elements, and the seaweed's natural phytohormones. It is fully water-soluble, with a pH of 4.5 and a density of 1.1.
The extract stimulates root and foliage development, and helps the plant cope better with a cold snap, a brief dry spell, strong winds, or water with too high a salt content. These effects depend on many factors, so a biostimulant should be assessed over several weeks of cultivation rather than after a single application. Use it on vegetables, herbs, flowering plants and young transplants, which often go through a period of slow growth immediately after being moved. For a cutting that has not yet developed roots, a rooting stimulant is more appropriate.
💧 Watering or spraying
For watering, dilute 5 ml of product per litre of water, that's 50 ml for a 10-litre watering can, and apply it to the base of the plant with every fertilising watering. In hydroponics, add the same dose to the reservoir nutrient solution before the fertiliser, then check the pH with a pH drop test kit, as the product is slightly acidic. For foliar spraying, reduce the dose to 3 ml per litre, once a week or after a stress event, applied to dry foliage. Both methods can be used together, as spraying acts through the leaves while watering acts through the roots.
Add the flowering booster as soon as the first buds appear
This extract can be used right through to the end of flowering. The organic flowering stimulator, formulated from the same seaweed, is added from pre-flowering through to fruit ripening, also at 5 ml per litre. Both are used together during pre-flowering and flowering, then the stimulator continues alone during ripening, giving you a plant-based biostimulant throughout the entire cycle.
Shake the bottle and rinse the sprayer
Shake the bottle before each use, as the extract contains suspended matter that settles to the bottom. Replace the cap firmly after each use and store the bottle in a dry place, between 5 and 30 °C. When spraying, apply at the end of the day rather than in full sun, then rinse the sprayer and its nozzle thoroughly with clean water.
🗓️ From seedling to flowering
The first application is made as soon as the first true leaves appear, those that follow the seed leaves, or as soon as a cutting has rooted and resumed growth. Continue with every feed watering throughout the growth phase, then stop feeding at the end of flowering and foliar spraying at pre-flowering. For a lettuce or a herb grown for its leaves, continue right through to harvest, as there is no flowering stage to wait for.
500 ml bottle
It prepares 100 litres of feed water at 5 ml per litre, enough to maintain a few trays or a balcony setup.
1 L bottle
It prepares 200 litres of feed solution, enough for the grow stage of a small hydroponic system.
5 L container
It prepares 1,000 litres of irrigation water for a vegetable garden or greenhouse throughout the season.
🐟 In aquaponics
In aquaponics, the plants receive fish water rather than a prepared nutrient solution, and anything added to the circuit also passes through the fish tank. Foliar spraying at 3 ml per litre sidesteps this issue entirely: treat the foliage during the cooler parts of the day, directing the spray away from the water, and the extract works without affecting water quality in the system. This method is also the most useful when your plants lack vigour in spring, while water temperature is still slowing bacterial activity and nutrient availability.
The product is made in France, in the Gers, from 100% plant-based ingredients. It is approved for use in organic farming under EU regulations 2018/848 and 2021/1165, and it falls under the category of natural substances for biostimulant use. Its safety data sheet does not classify it as hazardous. Store it for up to 2 years from the date of manufacture, in its original packaging, in a dry place between 5 and 30 °C, away from frost, which affects its texture.
Technical specifications
The product
- Active ingredient
- Extract of Ascophyllum nodosumCold-pressed
- Origin of ingredients
- 100 % plant-based
- pH
- 4.5
- Density
- 1.1
Use
- As a drench
- 5 ml/LFirst true leaves through to flowering
- As a foliar spray
- 3 ml/LEvery week, up to pre-flowering
- Crops
- Soil, coco fibre, hydroponics
- Organic farming
- Suitable for useRegulations (EU) 2018/848 and 2021/1165
The packaging
- Formats
- 500 ml, 1 L, 5 L
- Prepared solution
- 100, 200 or 1,000 L
- Storage
- 2 years, from 5 to 30 °C
- Manufacturing
- France
To budget for separately
- Switch at flowering
- An organic bloom stimulator
- pH measurement
- A pH test kit in drops
6 further specifications are available in the detailed view.
In the box
- 1 bottle of 500 ml or 1 L, or 1 container of 5 L, depending on the format chosen
Composition, pH, density, doses, application period and storage details recorded on 02/10/2026 from the manufacturer's product sheet, their safety data sheet V8 dated 17/07/2026, and their 2025 application chart. The product is also sold under the name Seaweed.
Documents & manuals
Safety data sheet for the seaweed extract
The data sheet details the composition, pH, and storage conditions of the liquid seaweed extract.
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Bottle or drum sent by tracked parcel from France. The exact costs and final delivery times are displayed at checkout once the address has been entered. Outside the European Union, import duties and taxes remain the responsibility of the recipient.
Frequently asked questions
6 questions
6 key questions
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