Executive Summary

In our simple experiment we started last November, our mealworm frass performed just as well as the traditional organic fertilizer. Frass also performed well as compost, acting as a soil amendment, in restoring old potting soil. In short, container gardeners can replace either their compost or organic fertilizer with Frassilizer™ when refreshing their soil.

Background on the Test

As a reminder from the prior post, we set up 3 treatments to compare.

• A - Soil + Compost + organic fertilizer.
• B - Soil + Compost + Frassilizer.
• C - Soil + Frassilizer.

In each container, we planted 2 lettuce starts, 2 chard starts, and 1 radicchio (center of the pot). As you can see from the pictures taken 68 days after planting, the size and quality of the different plants is very similar across all three treatments. On the more interesting side of things, the radicchio did not turn red. It seems we didn’t get cold enough weather, as this requires some freezing temperatures or frosts. Our mild SF Bay Area temperatures just didn’t do the trick.

We did get 197mm of measured rainfall during the test period, but had to supply a bit of water early January during a dry spell. Each treatment had the same water, temperature, and lighting conditions.

Each container had a protective layer of wire mesh surrounding it to protect the plants from deer, squirrels, birds, and other animals that might have been curious or hungry.

Results & Conclusions

Based on visual observations, we noticed the following:

1. Frass + Compost (B) and Frass alone (C) performed similarly to Fertilizer + Compost (A) for lettuce
2. Frass + Compost (B) and Frass alone (C) under performed to Fertilizer + Compost (A) for chard

We thought doing a taste test would be interesting too, but highly subjective and limited. What the heck, we did it anyway. What did we find? One subject (me) couldn’t tell any difference among the 3 taste samples. The other taste tester said that (B) tasted slightly bitter compared to the others and that C tasted the best.

The Chitin in frass provides a lot of powerful benefits to plants, especially leafy greens. Unfortunately, for our experiment, we didn’t notice any differences in how Chitin hardens up plants against pests or deterring insects by making them “itchy.” Why? Well we just didn’t have any observations of insects or other pests during the entire test period, nor was there any damage to any of the leaves on any of the treatments.

We’ll say it again, if you have an idea for a frass experiment of your own, let us know and we’d be happy to send you some free Frassilizer (up to 10 lbs) if you are willing to document and share your experiment results with us and our community. Or drop us a line and let us know what experiment you’d like us to run next.