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Seaweed: Best used as a foliar spray. Excellent source of trace minerals. Should be used often. Contains hormones that stimulate root growth and branching. Many trace elements are found in seaweed in the proportions they are found in plants. Seaweed contains hormones and functions as a mild but effective insect control, especially for whiteflies and spider mites. It acts as a chelating agent, making other fertilizers and nutrients more available to the plants. Seaweed or kelp is available in liquid and in dry meals.


Ascophyllum nodosum kelp
photo by The Dozens (Wikimedia)


Seaweed is an excellent material for foliar feeding and is even better when added to compost tea, vinegar, molasses, and liquid fish creating Garrett Juice. Seaweed also provides soil conditioning substances that improve the crumb structure or tilth. It is a good natural source of copper and boron. Use at 20-40 pounds per 1,000 square feet or 300-500 pounds per acre.


Kelp and seaweed are the same. Large brown seaweed, especially the families Laminariaceae and Fucaceae have been found valuable as soil conditioners. Ascophyllum nodosum is the species that has the most university research. Kelp is available in liquid or dry meal form.


Seaweed Research


Dr. T. L. Senn of Clemson University



Seaweed and Plant Growth by Dr. T.L. Senn


Seaweed has been researched as much as any organic product over the years by Dr. T.L. Senn. Anyone who has ever used liquid or dry seaweed doesn’t need any more convincing, but for the "show me" crowd – the research is there.


Dr. T.L. Senn was a professor at Clemson University. In 1987 he published a book called Seaweed and Plant Growth. He not only did research about the efficacy of seaweed as a soil amendment and foliar feeding material but its power to increase plant production from the trace minerals as well as the growth regulators. The research also proved that seaweed is an effective spray to control spider mites on infested plants. This research has been around for a very long time but people recommending the chemical treatments for spider mites such as Kelthane which is no longer on the market and other toxic materials never mentioned even the possibility of using this wonderful product.  Dr. Senn has received many awards for his research and publications, twenty of which relate to seaweed research. Seaweed can be easily found in all quality garden centers and feed stores.





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