Has anyone experimented with using Florel and B-9 as a tank mix on poinsettias? I have used it on geraniums with great success with Florel at 500 ppm and B-9 1250 ppm. I like the consistancy that you get with Florel, but I need a little more growth regulation due to the high temperatures in Texas. Any ideas of rates to use on poinsettias?

This combination is unusual for poinsettias. In most cool climates it would be too strong. In hot climates the question is do you get any benefit from Florel, so I usually suggest keeping them separate so you can make better decisions about what is working. But if you know that you need more height control on a vigorous variety at the same time you are spraying Florel you could add another growth regulator. For B-Nine alone or in combination with another product use 1,000 to 2,500 ppm. Do not go higher since there can be significant phyto in hot climates

An issue with combining Florel and B-Nine is spray solution pH. For Florel you want the pH below 5 to keep it active. However, B-Nine will go out of solution at a pH of about 4. Florel is a strong acid. There is a strong buffer in the B-Nine formulation to keep the pH up. So the two work against each other in the spray tank. Jim