Growing broccoli

[Michael Hause]

I started some broccoli from seed in small soil pots about 2 months ago. Once the plants were about 2 inches tall I transplanted them to my grow bed. The plants have grown so tall that they tipped over. I was expecting a shorter plant that would form flowers by now. Is there something that I need to do to trigger flower formation?

[Rob Tolette]

Broccoli is one of those plants that tends to be a bit trickier to grow in aquaponic systems.  I've done it in the past, but wasn't too happy with the flowering results I got.  It formed a head, but it was much smaller than what you find in stores (probably just poor crop/nutrient management on my part).  If your plant just keeps on growing without flowering, that is probably a sign of excess nitrogen and a lack of potassium and phosphorus in the system (which are the macronutrients required for fruiting/flowering growth).  

Some easy ways to increase P&K levels are to use potassium carbonate or potassium bicarbonate when you buffer your pH.  If you need to bring the pH down, you can use phosphoric acid.  Another option is to use a fish-safe hydroponic nutrient that is intended for flowering crops.

I hope this helps!

[Michael Hause]

Thanks Rob I will definitely see about supplementing my water chemistry. Hopefully my plants aren't too mature for this to work. I attached a photo. 

Rob Tolette said:

Broccoli is one of those plants that tends to be a bit trickier to grow in aquaponic systems.  I've done it in the past, but wasn't too happy with the flowering results I got.  It formed a head, but it was much smaller than what you find in stores (probably just poor crop/nutrient management on my part).  If your plant just keeps on growing without flowering, that is probably a sign of excess nitrogen and a lack of potassium and phosphorus in the system (which are the macronutrients required for fruiting/flowering growth).  

Some easy ways to increase P&K levels are to use potassium carbonate or potassium bicarbonate when you buffer your pH.  If you need to bring the pH down, you can use phosphoric acid.  Another option is to use a fish-safe hydroponic nutrient that is intended for flowering crops.

I hope this helps!