Make your garden thrive with Unco Industries Wiggle Worm Soil Builder Pure Worm Castings. It's an organic fertilizer that's chock full of the nutrients that your plants need. These wiggle-worm castings are ideal for use in all manner of indoor and outdoor gardens. They're completely nontoxic and free of the odors that come with other, manure-based fertilizers. It takes only a small amount of these castings to feed your plants, and it comes in a 30-lb per bag.