Does Seaweed Fertilizer Help Germination?

Misconceptions have been around for years about whether seaweed fertilizer helps with seed germination or not. Some gardeners and farmers believe it does and swear by it, while others do not believe it’s true and use a different fertilizer to aid in the sprouting process. In order to put the debate to rest, the use of seaweed in a vegetable fertilizer or a crop fertilizer for sprouting has been tested.

Independent Testing

In 2007, a study was held at North Carolina State University to determine whether or not fertilization of seeds was aided by using fish/seaweed emulsions, seaweed extract or fish emulsion alone. Pepper and tomato seeds were soaked overnight in solutions of all of these fertilizers, and the control group was soaked in water. The horticulturists determined that there was no difference in germination from one solution to another, nor from one fertilizer to water.


However, though germination isn’t affected, the growth of the plant is influenced by the presence of the nutrients which can encourage strong and hardy development. This is extremely important in transplanting saplings and adolescent plants from a greenhouse environment (or, one that is controlled) to an outdoor one. It can reduce the chances of literally shocking your plant into stunted growth or even death. It’s key to maintain a consistent nutrient feeding even in transplanting to guarantee robust maturity of your plants.

And so, even though seaweed fertilizer doesn’t help with the germination process, it’s still a good idea to have it in the soil at the time of germination. This will aide the plant later on, making it a healthier plant once it starts to grow.