A couple of weeks ago I started a fertiliser trial in the hydroponicum, pitting Hexafly frass against my regular Ikea feed. Today the plants look like this:

Top tier - Hexafly v Ikea feed

It’s the top tier that is running the experiment. The bottom tier is growing yummy lettuce (left) and pak choi and leaf celery (right).

The top left tier is the Hexafly frass:

Hexafly fed

And, as you can clearly see now, the plants there just aren’t growing as fast as the Ikea-fed ones:

Ikea fed

My original plan was to do a comparison of the growth, and then a taste test, but as it stands at the moment the two different trays aren’t going to be ready for harvest at the same time.

So what’s causing the difference? My guess at this stage is that the Hexafly Frass doesn’t contain enough phosphorus to encourage good root growth. Rather than ditch the experiment entirely at this point, Ryan recommended that I double the original Hexafly application rate and see if that helps. So I have added more Frass to the mix (and it pongs quite badly) and topped up the tray. I have topped up the Ikea tray with its feed at the same time.

I have checked the recommended application rate, and I did get it right originally. However, since I started the experiment, Hexafly has updated its website and changed the advice given for hydroponics. It originally said 1 cup (235ml) of frass in 10 gallons of water, now it says 365ml.

I am not massively hopeful that this extra feed will help, and certainly the Hexafly-fed plants aren’t going to be catching up with their Ikea-fed relatives. Wherever we go from here, it will have to be after Christmas.