Buying Guide for Bulk Worm Castings - Price, Size, & What to Know When Buying Castings in Bulk

In this guide to buying bulk worm castings, we’ll take a look at the key considerations - including price, sizes, shipping/delivery, castings quality and lab tests, and even how to store your castings – before you decide to take the plunge on a large bag of worm poop!

Bulk Worm Castings Weight & Size Options

One of the first things you will likely notice when shopping for bulk castings is that some sellers sell by weight (1,000 lbs) and others by cubic volume (e.g., 1 yard). For example, you might see the following options:

• 1,000 Lb (1/2 ton) Bulk Worm Castings in a Super Sack for Sale – Shipping included - $900

Or,

• 1 Cubic Yard Bulk Worm Castings in a Super Sack for Sale – Shipping included - $900

So, which one should you buy if price was your only consideration? The answer is you need more information before making a decision! Worm castings can vary significantly by weight from seller to seller, from 800 lbs per cubic yard to 1,600 yards per cubic yard. These differences are mainly due to feedstock used (bedding and feedstock will impact the final castings density) and moisture content (worm castings can hold a lot of moisture especially when fresh).

In the example above, the 1,000 lb sack and the 1 cubic yard sack could very well hold the same amount (by volume) of castings, but it is also possible (based on density and moisture content) that the 1,000 lb bag contains much less castings than the 1 cubic yard sack.

With the above in mind, we recommend buying worm castings in bulk by volume – or at least asking the seller what the approximate volume of the castings bag is – as volume gives a truer indication of the actual amount of castings in your bulk purchase.

In terms of sizes, most bulk buying options will be at least ½ cubic yard with bigger options including 1 yard, 1.5, yard and 2 yards. At times you will also see bulk options of 1000 lbs and 2000 lbs. In our experience a 2,000 lb (1 ton) size is between 1 and 1.5 cubic yards but we recommend confirming with the seller before deciding to buy. If converting to cubic yards is a problem ask the buyer how many gallons of worm castings are in the bag and you can easily back into the cubic number (200 gallons is ~ 1 cubic yard, 300 gallons is 1.5 cubic yards, etc).

Bulk Worm Castings Pricing

Due to differences in size, weight, quality, and location, pricing for bulk worm castings can vary significantly. Generally speaking, 1 yard of castings will be priced between $200 and $600 before shipping is calculated (see below for more info on expected shipping charges). Once shipping is added you can expect to pay anywhere from $800 - $1,200 per cubic yard of bulk castings.

Shipping Worm Castings in Bulk

Most bulk worm castings super sacks will be shipped on pallets via LTL (less-than-truckload) freight carriers. The carriers will pick-up the pallets/bags from the worm farm and then deliver to your location. Note that you will need a forklift or the freight truck will need a lift gate and pallet jack to unload the bulk casting bags. Since the bags will weigh 800-2,000 pounds it’s important to have the unloading options outlined before the shipment arrives.

Shipping via freight can be expensive so expect shipping to cost anywhere from a few hundred dollars for 1-2 super sacks to several thousand dollars and up for 10-20 super sacks. If you are buying a full truckload of castings, note that most freight companies have a 42,000 weight limit per truckload so you can usually receive 30-36 cubic yards (20-24 1.5 cubic yard sacks) per LTL delivery. Truck sizes and requirements can vary but this is a good benchmark for planning purposes.

One other quick thought related to shipping – it is possible to stack palletized castings so if your seller offers this option it can save on shipping since freight providers will generally charge less for stackable pallets.

Bulk Castings Quality and Lab Testing

Similar to weights and volumes in castings, castings quality and lab test results can vary greatly from worm farm to worm farm due to process, inputs (feedstock and bedding), the compost worms, and other variables. In general, quality refers to the trace elements and nutrients in the castings as well as the levels of active biology and enzymes that helps plants thrive.

Most buyers of bulk worm castings are professional growers and understand in detail what they are looking for in a casting product. If you are not familiar with the science of soil and castings but are looking to buy worm castings in bulk, we recommend at least requesting a lab report from the castings supplier (and if they won't/can't supply one it might be a red flag). Although the report will be scientific in nature, you can review the report and get a sense of the castings quality. Most reports will show actual and recommended levels of nutrients, elements, pH, and bacterial levels, and many reports will be color-coded (green is good!) to help you understand the results. The report will also highlight if the castings are bacterial (generally good for garden/grain/vegetable crops ) or fungal (generally good for trees, vines, and shrubs).

Who Buys Worm Castings in Bulk?

Most folks buying worm castings purchase small batch bags in 4-8 quart (2-5 lb.) sizes. These bags are a great option if you are buying worm castings for your houseplants or a smaller garden area. Some buyers – specifically soil mixing and amendment companies, cannabis growers, organic nurseries, and other professional grow operations – buy worm castings in bulk sacks of 1-2 cubic yards (ranging in weight from 1000-2000 pounds). We have also seen neighbors and homeowner’s associations pitch in to buy castings in bulk and take advantage of the bulk pricing discount.

 How to Store Bulk Worm Castings

Storing bulk super sacks of worm castings (and any worm castings for that matter) is pretty straightforward:

• Store away from direct sunlight. Most bulk super sacks are not UV-resistant so they will not protect the biology in the castings from harmful UV sunlight.
• Keep dry and away from direct moisture sources like rain.
• Keep the castings covered so that they do not dry out and lightly water the top layer of castings from time to time (most of the castings in the bag below the top layer will stay moist ).
• Castings can generally be safely stored for 12-18 months if done correctly.

We’ve seen castings stored in their original super sacks in garages, barns, and sheds, or outside with a tarp covering them (to protect from sunlight and moisture). We’ve also seen them dumped in a pile on the ground covered by a tarp, and although this probably works ok we don’t recommend it as the castings can be subjected to too much moisture or even critters using the pile as a bathroom!

Buying Bulk Castings Wholesale Online

Brothers Worm Farm offers worm castings in bulk starting at $895 (shipping included) per yard. If you have questions or need more information on our castings or process, please reach out to us at highfive@brotherswormfarm.com. Thanks for reading and happy farming!

Thanks for reading and don’t hesitate to reach out if you have any questions or need more info on worm farming or bulk worm castings!