Second Fertilization With A Kelp Product

Q: Following a pruning of our camellia hedge the professionals did a deep root fertilization and recommended a second fertilization with a kelp product. What do you think? 

A: The use of biostimulants (including humic substances, seaweed extracts, and beneficial bacteria and fungi) in agriculture and horticulture certainly has a lot of marketing and hype associated with it. Although there is a lot of potential and hope, I have not yet seen research that shows conclusively the usefulness or effectiveness of biostimulants outside of a laboratory. It seems to me that you could achieve the same results using proper landscape management, including mulching and conventional fertilization.