The uselessness of high P fertilizers
Some of you may recall that I have long maintained that high phosphorus(P) fertilizers are pointless.
I also am a fan of Dyna-Gro fertilizers for container usage.
I was asked recently 'If high P fertilizers are so useless then why does Dyna-Gro make and market them?'
My answer was simply to have a product that people wanted, but that was just my opinion. I decided to ask the company (Dyna-Gro) about this. At first I got a very brief response from a representative that wasn't at all satisfying so I asked that rep to forward my question to someone responsible for deciding what their formulations would be. I ended up getting a response from the CEO. Here it is, I think you will find it interesting.
You are correct. We market a high P (Liquid Bloom) "believe" they need this. As you have noted, our Foliage-Pro does a great job start to finish. However, it is simpler to give the market what they think they need than to try to reeducate it. There is some evidence to believe that low N helps to convince a plant to stop its vegetative growth and move into its reproductive phase (flowering), but environmental factors are probably more important. P is typically 5th or 6th in order of importance of the six macronutrients. There is little scientific justification for higher P formulas, but marketing does come into play for the vast majority of users who lack any real understanding of plant nutritional requirements. Therefore, the market is flooded with a plethora of snake oil products that provide little benefit and can actually do harm. For example, one exhibitor at a hydroponic trade show had a calcium supplement with 2% calcium derived from calcium chloride. Can you guess what continued application of 2% chloride would do to plants?'\
I hope this answers your question and am sorry for Zina's inaccurate response.
Dave Neal, CEO
Dyna-Gro Nutrition Solutions
2775 Giant Rd.
Richmond, CA 94806
800-Dyna-Gro, Fax: 510-233-0198