Seasol is a concentrated liquid seaweed treatment designed to improve overall plant health, encourage strong root development and help plants cope with environmental stress. It can be used throughout the garden on vegetables, herbs, flowers, fruit trees, lawns, indoor plants, Australian natives and established trees.
Made from a blend of brown kelps, Seasol contains naturally occurring plant nutrients, trace elements, alginic acids and other bioactive compounds that support healthy plants and beneficial soil microorganisms.
When Should You Use Seasol?
Seasol is particularly useful when you want to improve plant health and establishment rather than simply supply large amounts of fertiliser.
- Planting new seedlings, shrubs and trees
- Reducing transplant shock after planting or repotting
- Helping stressed plants recover from heat, drought or frost
- Encouraging strong root development
- Supporting flowering and fruiting
- Improving seed germination
- Supporting beneficial soil microorganisms
- Helping plants make better use of applied fertilisers
- Maintaining general plant health throughout the year
Is Seasol a Fertiliser?
Seasol contains nutrients and trace elements, but it is primarily a plant and soil health treatment rather than a high-analysis fertiliser. Typical analysis of Seasol Liquid Seaweed Concentrate is approximately 0.1% nitrogen, 0.01% phosphorus and 1.5% potassium.
If your main goal is to supply nutrients for stronger plant growth, Seasol is best used alongside an appropriate fertiliser rather than as the only fertiliser.
For example, PowerFeed is a higher-nutrient liquid fertiliser containing nitrogen, phosphorus and potassium and is designed to actively feed plants. Seasol and PowerFeed can be applied together in the same watering can. Seasol helps improve nutrient uptake, making it an excellent companion to regular fertilising.
Seasol or PowerFeed – Which Should You Use?
| Choose Seasol When You Want To | Consider PowerFeed When You Want To |
|---|---|
| Encourage strong root development | Provide more substantial plant nutrition |
| Reduce transplant shock | Promote vigorous leafy growth |
| Support stressed plants | Feed vegetables, flowers and established plants |
| Improve general plant and soil health | Supply higher levels of nitrogen and potassium |
| Improve nutrient uptake | Encourage strong growth and productivity |
For general garden care, Seasol and PowerFeed can also be used together to provide both plant-health benefits and additional nutrition.
Key Benefits of Seasol
- Stimulates strong root growth and beneficial soil microorganisms
- Promotes healthy flowering and fruiting
- Helps plants cope with heat, drought and frost
- Supports plant resilience during pest and disease pressure
- Improves seed germination
- Helps reduce transplant shock
- Improves nutrient uptake from applied fertilisers
- Safe for all plants, including Australian natives
How Seasol Works
Seasol is produced from a blend of brown kelps including King Island Bull Kelp, Chile Bull Kelp and North Atlantic Knotted Kelp. These seaweeds provide naturally occurring compounds that support root development, plant health and beneficial biological activity in the soil.
Seasol can be applied to both the foliage and the soil around plants, allowing it to be used across a wide range of gardening situations.
Seasol Application Rates
| Application | Rate per 9 L Water | Frequency |
|---|---|---|
| Indoor Plants, Ferns & Foliar Application | 20 mL | Every 2–4 weeks |
| Transplanting & Planting | 40 mL | At planting and again 1 week later |
| Vegetables, Herbs & Annuals | 40 mL | Every 2 weeks |
| Established Gardens | 40 mL | Every 2–4 weeks |
| New Lawns | 60 mL | Every 7–10 days while establishing |
| Established Lawns | 100 mL | Every 2–4 weeks |
| Large or Stressed Trees | 100 mL | Monthly around the dripline |
A 9 L diluted mixture treats approximately 2–4 square metres of garden or lawn.
Planting and Transplanting
For new plants, apply Seasol at planting and again approximately one week later. Seedling trays or potted plants can also be soaked in diluted Seasol before planting to help establishment and reduce transplant shock.
Seeds can be soaked in diluted Seasol before sowing to help improve germination.
Using Seasol During Hot or Cold Weather
During summer, apply Seasol in the early morning or early evening before the hottest part of the day. During winter, apply in the morning after frost has cleared so plants have time to dry before nightfall.
Suitable Plants
Seasol is suitable for use on virtually the entire garden, including Australian native plants, vegetables, herbs, annuals, flowers, fruit trees, shrubs, indoor plants, ferns, lawns and established trees.
General Precautions
Keep out of reach of children. Not to be taken. May irritate skin and eyes. Wash hands after use. Wash edible plants before eating and use diluted mixtures within 24 hours of mixing. Avoid contact with porous surfaces and rinse immediately with water if spills occur.
Frequently Asked Questions
Is it safe to put Seasol on a lawn that a pet rabbit lives on?
After contacting a representative from Seasol, we were advised that using Seasol on a lawn where a rabbit lives would very likely be fine, as Seasol contains virtually no nitrogen or phosphorus compared with conventional fertilisers. Apply Seasol according to the label directions. As an additional precaution, allow the treated lawn to dry before allowing pets back onto the area.
Can Seasol be used on vegetables and other edible plants?
Yes. Seasol can be used on vegetables, herbs, fruit trees and other edible plants. Seasol advises that there is no withholding period after applying Seasol before harvesting fruit or vegetables. As with all plant treatments, wash edible produce before eating.