Unco Industries Earthworm Castings Garden Fertilizer

Last updated: June 1, 2023


Earthworm castings set this garden fertilizer apart from the competition. This organic fertilizer provides a nontoxic, odorless alternative for gardeners. The healthy bacteria in these castings promote plant growth.

We looked at the top Garden Fertilizers and dug through the reviews from some of the most popular review sites. Through this analysis, we've determined the best Garden Fertilizer you should buy.

Product Details

Key Takeaway: If you want a natural fertilizer, the earthworm castings in this organic garden fertilizer make it a great choice.

In our analysis of 26 expert reviews, the Unco Industries Earthworm Castings Garden Fertilizer placed 12th when we looked at the top 14 products in the category. For the full ranking, see below.

From The Manufacturer

Soon to be known as the “World’s Greatest Organic Fertilizer!” Wiggle Worm Soil Builder PURE earthworm castings are surely Mother Nature’s best kept growing secret. You need only use a small amount in or around your houseplants, vegetables and flowers. The miracles of the earthworm are easily seen in the beautiful growth and yields of your plants. The nutrients in our earthworm castings are plentiful. Most importantly, these nutrients are perfectly balanced in two forms. One form can be immediately absorbed by the plant as if it were directly injected and the other is able to provide nutrition which slowly feeds the plant for long periods of time. This soil builder is very cost effective because small amounts provide incredible results and last a long time.

Our Expert Consultant

Vicki Liston 
Home Improvement Expert

Vicki Liston writes, produces, and narrates “On The Fly…DIY,” an award-winning home improvement and DIY show of unique project tutorials for the casual DIY’er.

Home improvement and all things DIY have been Liston’s passion since she bought her first house in 2007 and she started making video blogs in 2014. She’s performed hundreds of DIY projects, from small ones to major, wall-smashing renovations and can teach you how to make a trendy DIY barn door for cheap. The proceeds earned from “On The Fly…DIY” are donated to no-kill animal shelters and rescue organizations.

Expert Reviews


What reviewers liked

They have lots of healthy bacteria that grows from the waste, which helps increase plant growth at a high rate of speed. The product has been sifted through before shipment, so there’s less work for you to do when it arrives.
The nutrients in our earthworm castings are plentiful. Most importantly, these nutrients are perfectly balanced in two forms. One form can be immediately absorbed by the plant as if it were directly injected and the other is able to provide nutrition which slowly feeds the plant for long periods of time.
Earthworm castings (i.e. their dung) contain water-soluble nutrients that come out of the worm in a richer format than they had before going into the worm, and the result is plant food gold.
The pure earthworm eastings offer great fortification and support for the soil base, and I found it useful for growing not only my vegetable crops, but also flowers on the side.
The worms from Unco are fed with organic materials that are rich in organic material, which usually contains traces of elements and different types of minerals.
Their Wiggle Worm soil builder ingredients come from straight nature with no alteration. It contains varieties of minerals and trace elements will nourish your garden to the fullest.
The wiggle worm soil builder has the ability to improve soil structure which allows the roots of your garden plant to grow fast. It also increases soil water retention capacity because it contains absorbent organic matter which holds only the required amounts of water needed by the plant roots and it is odorless.

What reviewers didn't like

Growth may start slowly in the early stages.
My first bag did come with some mold on the top layer.
Mystery seedlings might pop up.
View our Garden Fertilizer buying guide for in-depth advice and recommendations.

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