Boost Your Red Wiggler or Nightcrawler Population with a DIY Breeder Jar

Spring is quickly approaching here in Central Pennsylvania. Post-holiday clearance displays are being replaced with seeds and bulbs for the upcoming growing season, and anglers are getting in line to get outfitted for the highly-anticipated first day of the Pennsylvania trout season. (April 4, 2020, in my area)
It doesn't matter whether you need nutrient-rich, organic fertilizer (worm castings) for your plants, or a fat, wiggling bit of enticement on the hook, making a breeder jar to have access to a thriving, healthy population of worms or nightcrawlers is going to be very beneficial to your springtime hobby.

The Basics of a Breeder Jar for Red Wigglers or Nightcrawlers

There are many styles of worm farms available for sale commercially, and quite a few DIY worm farm tutorials that all work just as well. Most of the products and plans available can get a bit pricy to populate with enough worms or nightcrawlers to do the composting that needs to be done though. (My first "free" DIY worm bin cost me a little over $60 to populate with red wigglers!) 

The breeder jar is set up a lot like almost all of the other worm bins, but the idea isn't to produce castings. The purpose of the breeder jar, as the name implies, is to produce red worm and nightcrawler cocoons quickly and inexpensively to be added into bins, cold compost piles, or straight into the garden.

Unlike the other worm bins though, a small amount of space and a small number of worms will produce results very quickly in a breeder jar. The idea behind a breeder jar is that the worms don't have anything else to do, or anywhere else to go,(like they do in a larger worm bed) so they just eat and reproduce. 

Note: Worms will self-level their populations and quit reproducing when they are beginning to run out of space. The system I am going to build today is very small but it takes only a small amount of worms to produce big results!

It's also a very good composter for a small space like an apartment or office, capable of composting around a pound of organic material a week.

Tools and Materials:

• Scissors, shears or a paper shredder
• Drill and drill bit
• Measuring cup and spoon
• Large container for soaking bedding
• 1-Gallon wide-mouthed plastic container with a lid (Use a container that was never used to store anything toxic or any chemicals. My container is a jar that had protein powder in it.)
• (Optional) Paint or duct tape if you have a clear container 
• Peat moss, coconut coir, garden soil, (free of fertilizers or toxins), or commercial worm bedding 
• (Optional) Extra carbon materials like cardboard, newspaper, paper towels, wood chips, or dried leaves
• A gallon of unchlorinated water
• Cloth big enough to cover the mouth of the jar
• Rubber bands
• 250 Red wigglers or 100 nightcrawlers
• Fruit and vegetable scraps or commercial worm food
• Grit ( Nightcrawlers and red worms have gizzards. They need a source of grit like sand, coffee grounds, pulverized limestone, or ground eggshells to break down food.)

Making the Breeder Jar:

Breeder jar all painted and ready to fill with bedding.

1. Paint or tape up the outside of the jar. Worms don't like the light. It can make them very unhealthy and even kill them.
2. Drill holes in the lid for air circulation.
3. Shred any extra carbon-rich materials into smaller pieces. 
4. Hydrate 6 cups of bedding materials and 2 cups of extra carbon-rich materials by soaking them in the water.
5. Thoroughly wring out handfuls of the bedding materials and loosely fill the breeder jar with it until it's about 3 inches deep.
6. Dust 1 tablespoon of grit across the top of the bedding in the jar.
7. Finish wringing out the rest of the bedding and loosely dropping it in the jar. (My breeder jar ended up being about 2/3 full.) DON"T PACK THE BEDDING DOWN!!
8. Dust another tablespoon of grit across the top of the bedding.  

This is my breeder jar with half of my bedding materials added. It's hard to tell from the angle that the picture was taken but there are somewhere between 3 and 4 inches of material in here.

Introducing the Red Wigglers or Nightcrawlers to the Jar 

All of my European Nightcrawlers have fully gone into the bedding. They drug most of the grit down into the bedding with them. The white specs are what's left of the crushed oyster shells that I used.

1. Pour the worms on top of the soil and let them work their own way down into the bedding materials naturally. ( Turn on a bright overhead light to drive them down if they are being stubborn.)
2. Dust the top of the bedding with a tablespoon of the food of your choice.
3. Put the lid on the breeder jar and use the rubber bands to secure the cloth over the lid.
4. Allow the worms to settle for 48 hours in a cool, (45-70 degree) dark, and damp area like a basement, garage, or under a sink.

Maintaining and Harvesting a Breeder Jar:

When you finally get to open the breeder jar after 48 hours you want to make 3 main observations:

• Does it stink when you open it? A sour odor means that anaerobic bacteria have taken over. This can usually be cured bt a gentle stirring of the jar.
• Does the bedding seem too wet or dry? Wet bedding can be fixed by adding in some dry bedding and gently mixing it in. Dry bedding can be fixed with a mist bottle full of water.
• Is there any food left? If there isn't any food left then add another tablespoon of food to the top just like before.

1. Check the breeder jar every 48 to 72 hours and make these same observations and correct them in the same ways until you start to see cocoons.
2. After cocoons start to appear feedings are going to need to be larger. This is also when I start wet feeding my worms with fruit and vegetable scraps. (1/8 of a cup of melon rinds, cucumbers, squash, or banana in addition to my dry worm food really seems to get my worms producing.) This is also when I start adding a pinch of grit with each feeding.
3. After 30 or 50 days have passed, use a 1/4inch screen to separate the castings in the breeder jar from the worms and cocoons.
4. Reintroduce fresh bedding into the jar along with the original amount of worms or nightcrawlers that you started with and any material that didn't pass through the screen. (If you don't feel like counting them out, it takes roughly 1/4 pound of red wigglers or nightcrawlers to start this breeder jar.)
5. Use the remaining nightcrawlers or worms and cocoons to stock a fresh worm bin, bait cooler, cold compost pile, or throw them right in the garden.

Finished breeder jar stocked with European nightcrawlers sitting on top of my first successful nightcrawler bin. The bedding still seemed a little wet to me so I added the cloth without adding the lid first to let some moisture evaporate off.

If you'd like to read a free article on how I turned 1/2 pound of European Nightcrawlers into 3 1/2 pounds in 1 year click here.

Transparency:

If you click any links on this page and make any purchases as a result of those clicks, I make an affiliate percentage for the purchase. Thank you very much in advance if you do happen to do that. It really helps to support and grow my blogs and articles.