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Vermicomposting Made Easy: In-Bed Worm Composting

Vermicomposting Made Easy: In-Bed Worm Composting

Worm composting directly in the garden bed simplifies the process of vermicomposting. When you use in-bed vermicomposting bins, the worms live, work, reproduce, and make worm castings in the garden bed, right where they are needed. 

In-bed vermicomposting solves the problem of what to do with the worms during extremes of hot and cold. For example, vermicomposting in hot weather places (like the low desert of Arizona) is difficult unless you bring the worms inside during the summer months. With in-bed vermicomposting, the worms simply burrow deeper in the beds during the heat of an Arizona summer, and then emerge again in the fall. 


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How does vermicomposting work?

Worm composting – also called vermicomposting (‘vermi’ = worm) – is the process of using worms to compost food scraps into vermicompost. Worms eat up to half their weight each day in kitchen scraps, and the byproduct of all that eating is worm castings. Worm castings = GARDEN GOLD!

During the digestion process, the worms secrete chemicals that break organic matter into nutrition that is readily available for plants. Worm castings, along with the chemicals secreted during digestion, make up vermicompost.

Vermicomposting Made Easy: In-Bed Worm Composting

What are the benefits of worm composting (vermicomposting)?

  • Vermicompost improves soil texture and structure, and aerates the soil
  • Vermicompost increases the water-holding capacity of soil. 
  • The nutrients in vermicompost are immediately available to plants
  • Worm castings contribute to faster plant growth and higher production.
  • Worm castings are dense in microorganisms and nutrients.
  • The chemicals in worm castings help prevent “damping off” and other diseases.
Vermicomposting Made Easy: In-Bed Worm Composting
Worm castings from vermicomposting

What is the easiest way to make and maintain a vermicomposting (worm composting) bin?

A vermicomposting bin built into your raised beds, containers, or in-ground garden bed is the easiest way to make a worm composting bin. 

No need to harvest the worm castings or move the worms inside for extremes of hot and cold temperatures. The worms live, work, reproduce, and make worm castings in the garden bed, right where they are needed. 

Vermicomposting Made Easy: In-Bed Worm Composting
Adding worms to an in-bed worm composting bin

When should I add in-bed vermicomposting bins to by garden beds?

Vermicomposting Made Easy_ In-Bed Worm Composting

If you live in a hot summer climate, do not add worms during the hottest months of the year. In the low desert of Arizona, the best time to add in-bed vermicomposting bins to your garden is from mid-September through May.

Nighttime temperatures should be consistently below 85°F when adding worms to your beds.


Which type of worms should I use for in-bed vermicomposting?

Red wigglers are composting worms that hang out in the top six inches of your garden. “Earthworms” is a generic term for one of the hundreds of varieties of worms. If you dig them from the garden, they won’t stay in the compost level.

That’s not bad, but they won’t hang out in the habitat we set up. Most bait worms need cooler temperatures than Arizona summers. If you are buying nightcrawlers, you will probably lose them in June or July. We want all worms. Red wigglers will stay and live better, but no worm is bad.

Purchasing red wiggler worms locally is the best choice. I get my worms from Arizona Worm Farm here in Phoenix. You can also buy them online from Uncle Jim’s Worm Farm.


How do I make an in-bed vermicomposter (worm composter)?

Supplies needed for in-bed vermicomposting:

Vermicomposting Made Easy: In-Bed Worm Composting
The 24-sheet shredder I use to shred cardboard for my vermicomposting bins
  • Bin (see options below).
  • Shredded cardboard – I use this shredder from Amazon to shred my cardboard boxes (remove tape and labels first).
  • Kitchen scraps.
  • Worms – Red wigglers are preferred. The earthworms typically found in the garden aren’t suitable for vermicomposting.

Bin options for in-bed vermicomposting:

The bin helps designate a place in your garden for the worms to go. Choose one slightly smaller than the depth of your garden bed. There are several options:

Vermicomposting Made Easy: In-Bed Worm Composting

Vermicomposting Made Easy: In-Bed Worm Composting

Vermicomposting Made Easy: In-Bed Worm Composting
  • Shape hardware cloth into a cylinder slightly shorter than the depth of your garden bed.
  • Wire the ends of the hardware cloth together.

Vermicomposting Made Easy: In-Bed Worm Composting
  • 2-gallon bucket (with the bottom removed and holes drilled in the sides)
  • I used this drill bit (for drilling holes) and a Dremel (to cut off the bottom of the bucket).
  • If you use this type of vermicomposting bin, it is STRONGLY RECOMMENDED to remove the bottom of the bucket.

Directions for installing and using an in-bed vermicomposting bin:

Vermicomposting Made Easy: In-Bed Worm Composting

1. Dig a hole in the garden bed the size of the bin.

Place the bin in the hole

2. Place the bin in the hole.

Fill the habitat with shredded cardboard, and wet it down. Allow cardboard to absorb moisture overnight.

3. Fill the habitat with shredded cardboard, and wet it down. Allow cardboard to absorb moisture overnight.

Add 300-600 red wiggler worms to the worm habitat.

4. Add 300-600 red wiggler worms to the worm habitat.

Begin feeding worms - see worm feeding details below.

5. Begin feeding worms – see worm feeding details below.

Cover the food scraps with a layer of "brown" materials. Examples: wood chips, dried leaves, soil, shredded cardboard

6. Cover the food scraps with a layer of “brown” materials. Examples: wood chips, dried leaves, soil, shredded cardboard.

Cover the worm habitat. I use a tile. They are very inexpensive and the right size for my habitat. You could also use a piece of wood. If you are using a bucket, the bucket lid works well.

7. Cover the worm habitat. I use a tile. They are inexpensive and the right size for my habitat. You could also use a piece of wood. If you are using a bucket, the bucket lid works well.

Check back occasionally and add more food scraps. (Always top with brown). Remove any large pieces of uneaten food.

8. Check back occasionally and add more food scraps. (Always top with browns). Remove any large pieces of uneaten food.

When food scraps are gone and the bucket is empty, you can harvest the castings. (The worms will leave the bucket and be in the bed). Spread the castings around the garden bed. You can also leave the castings in place.

9. When food scraps are gone and the bucket is empty, you can harvest the castings. (The worms will leave the bucket and migrate to other areas of the bed). Spread the castings around the garden bed. You can also leave the castings in place.

Begin the process over again, starting with fresh shredded cardboard, food scraps, and brown. No need to add additional worms.

10. Begin the process over again, starting with fresh shredded cardboard, food scraps, and browns—no need to add additional worms.


A note about sizes of in-bed vermicomposting bins:

My raised beds are 15 inches deep, 4 feet wide, and 8 feet long.

I have two worm habitats in each bed. If your beds are smaller or larger, adjust the size and number of buckets accordingly. 

I split one bag of worms between two worm habitats. Each bag contains about 3/4 of a pound of worms (around 500-700 worms, including babies, cocoons, and habitat).


What do worms eat?

Good for feeding wormsAvoid feeding worms
Coffee grounds, grains, tea bags, vegetables, fruit, eggshells, paperDairy, oily food, spicy food, meat, citrus, salty foods, alcohol, glossy paper
Tips for feeding worms in vermicomposting bins

Tips for feeding worms:

Tips for feeding worms in vermicomposting bins

Add equal amounts of greens and browns each time you feed.

  • Make sure worms have eaten previously-added food scraps before adding more. Plan on feeding worms about once per week.
  • Cut or blend food before adding to bins. Smaller pieces of food break down faster and speed up the composting process. 
  • After adding food scraps (greens), cover with browns to avoid attracting fruit flies
  • Remove large pieces of uneaten food. Pay attention to what the worms are eating and not eating. 
  • The interior of the bin should have the moisture consistency of a wrung-out sponge (damp but not overly wet). Spray lightly with a hose if necessary.
  • Replace lid on bucket after feeding
In-bed vermicomposting bins built into your garden simplifies worm composting. The worms live & make worm castings right in the garden beds.


Frequently asked questions about in-bed vermicomposting:


Question: I have a ton of black soldier fly larvae in both of my bins. Will they be detrimental to my red wigglers?

Answer: Black soldier flies are unusual in the Phoenix metro area because it is so dry here. They won’t hurt the worms, and within two or three weeks they pupate into harmless flies (the live fly has no mouth – the only stage of the insect that eats is the larvae) that die within a day or two.  

The larvae are voracious eaters so someone that finds them in the bin should feed much more than normal. If they put buckets or bins in the ground like your set up, they may observe fewer worms in their bucket or bin as the worms will move away from the heat the larvae produce.  

The worms are fine and will return when the larvae leave. The larvae don’t bite – if someone wanted to remove them (easiest is with a kitchen strainer) and toss them, that is a fine option too.


Question: I dug into two of the buckets to see how my worms were doing, and they were missing. Not a worm to be found in either bucket. Would you expect the worms to stay in that bucket full of compost, or have they perhaps left their original home and are now crawling around through the rest of my garden, maybe just coming back to the bucket for their meals?

Answer: The worms go throughout the beds and then there are usually some in the buckets with the scraps. I’m guessing with the intense heat we are having they are burrowing down as deep as they can go.


in-bed vermicomposting
Adding fresh shredded cardboard after emptying the bucket of the worm castings. The worms will return to the bins.

Question: I have two guinea pigs, and feed them alfalfa hay, organic alfalfa pellets, and leafy greens such as romaine lettuce, spinach, swiss chard, and parsley. They produce a lot of waste (approximately 1 quart of waste hay and pellets daily). I read that I can add their waste and their waste hay directly to my raised bed gardens, which I have been doing and have been digging it in with a hand spade. Will red wiggler worms compost the guinea pig waste and waste hay?

Answer: Red wigglers will eat guinea pig manure as it decomposes – and, they will not eat anything that they don’t like until it decomposes enough for them to eat. A pound of worms will eat about a pound of waste a week. You are likely to be producing a lot more than that, but that’s not harmful either. The worms will eat what they want, and the rest will feed your beds as it has.  Your current process is probably producing good results – the worms will make it better.


in-bed vermicomposting
Full bin of food and castings. Let the worms complete the food before harvesting the castings.

More frequently asked questions about in-bed vermicomposting:


Question: How often do you have to add water to the compost buckets in Arizona heat?

Answer: The beds get watered 2-3 times a week during the summer and about once a week in the winter. The buckets are in the middle of one of the watering grids in my beds and get watered as well.


Question: Can you add chicken poop to the buckets?

Answer: You can, in small amounts. Too much will overwhelm the worms. Just mix the poop with bedding (anything that was a tree…leaves or shredded cardboard or mulch) and they will do great.


Question: Do the finished castings seep into the garden through the holes in the bucket or does it need to be scooped out?

Answer: Both. It is carried out of the bed by the worms movement. When the worms have completed the food scraps you can also scoop the castings out and spread them around the bed. You then begin the process again, adding fresh cardboard and food scraps. The worms will come back into the bin. 


in-bed vermicomposting
Red wiggler worms are perfect for in-bed worm composting.

More frequently asked questions about in-bed vermicomposting:


Question: How do the in-bed vermicomposting worms do during the summer? Is there anything special you do to keep them cool during Arizona summers so they don’t die?

Answer: They burrow down into the beds and look for cool spots to stay cool. In-bed worm composting in Arizona is a great option for our hot summers. Beds should be at least 12 inches deep. 


Question: Do you ever have problems with ants attacking the worms in the in-bed vermicomposting bins? 

Answer: Ants don’t generally attack worms. By making the area a little moister, you can discourage ants and make the habitat better for the worms. You can use these ant bait traps


Question: WIll in-bed vermicomposting work in containers?

Answer: Generally, it will work fine. The challenge with worms in pots for most people is that they tend to let plants get root bound and there is less soil than the worms like. As long as you have organic material and space for them to move they will do great. You don’t need to bury a bin in the container. You can do the same thing if you just dig out a hole and put a lid on the hole.


in-bed vermicomposting

More frequently asked questions about in-bed vermicomposting:


Question: Can worms eat bokashi compost?

Answer: Absolutely. Done right, bokashi produces lots of microbes and breaks down waste to make it easier for the worms to consume.


Question: My bed is raised completely off the ground, due to the previous owner PLANTING Bermuda grass (sigh). I’ve been reading that these sorts of beds are not a good home for worms since they may get too hot or drown. We are in Arkansas, so it doesn’t typically get above 100, the bed has good drainage, and has a soil depth of about 10″. Do you think worms would be OK to add or no?

Answer: We never worry about drowning worms. They will find dry places to hang out. If she can grow vegetables, the worms will be fine. Fully-raised beds (off the ground) do tend to get hot. She should shade it in the summer, but they will probably be fine. The worst thing that might happen is they die over the summer and she has to add more in September when they start getting cooler nights.


Question: Will chemical fertilizers hurt the worms?  

Answer: In small amounts, probably not, but direct contact or a large amount could. The whole idea of worms is to let them convert organic materials into a natural source of nitrogen. The worms should reduce or eliminate the need for inorganic fertilizers. Chemical fertilizers such as inorganic nitrate salt will reduce the pH, but they also kill some of the microbes we like.


in-bed vermicomposting
Spreading worm castings around a raised bed garden.

More frequently asked questions about in-bed vermicomposting:


Question: Can I use earthworms or do I need to use red wrigglers for in-bed vermicomposting?  

Answer: Red wigglers are composting worms that hang out in the top six inches of your garden. “Earthworms” is a generic term for one of hundreds of varieties of worms. If you dig them from the garden, they won’t stay in the compost level. That’s not bad, but they won’t hang out in the habitat we set up. Most bait worms need cooler temperatures than Arizona summers. If you are buying night crawlers, you will probably lose them in June or July. We want all worms. Red wigglers will stay and live better, but no worm is bad.


Question: Can I feed my vermicomposting worms bread?  

Answer: Yes. Grain-based items are fine (i.e., crackers, cooked rice, pizza crust, and bread). 


Question: What do I do about cockroaches in my bins?  

Answer: Cockroaches can be hard to eliminate completely, but the best bet is to aggressively cover the food waste with browns. Adding at least an inch of browns on top will help. 


How to Compost: 10 Simple Steps for Composting Success

Want more information about composting? This article shares 10 simple steps to get you started. 


If you enjoyed this post about in-bed vermicomposting, please share it:


Dan

Friday 19th of August 2022

I have garden/flower bed with 15 2 gal bins. Should I add food to to all of them or just a few at a time? The bins are 4' away from each other side by side and about 6' away up and down. Thanks for your knowledge!

Angela Judd

Wednesday 24th of August 2022

You can add food to all of them. Each bin is its own system. Wait to add more until the worms have eaten what is there.

Peggy

Thursday 14th of July 2022

I live in Montreal, with cold winters. I vermicompost indoors. Would in-bed worm composting in my 22” deep raised garden boxes work, or would the worms freeze? What about in in-ground areas of my garden?

Angela Judd

Tuesday 19th of July 2022

Check with local growers to be sure. I've had others in cold climates tell me they mulch their beds very well with straw and the worms survive.

Stan Csapo

Monday 23rd of May 2022

Do the lids need to be on tight or open a bit for air circulation when you put pail bins in the garden and should you water the area around the bucket to keep the soil moist around it for the worms to go through?

Angela Judd

Tuesday 24th of May 2022

The lids can be on tight, but don't have to be. Yes, watering the soil around the buckets is a good idea.

Courtney

Thursday 17th of February 2022

My bed is raised completely off the ground, due to the previous owner PLANTING Bermuda grass (sigh). I've been reading that these sorts of beds are not a good home for worms since they may get too hot or drown. We are in Arkansas, so it doesn't typically get above 100, the bed has good drainage, and has a soil depth of about 10". Do you think worms would be OK to add or no? Thanks!

Angela Judd

Friday 18th of February 2022

Hi I double checked with Zach at Arizona Worm Farm on this, here is his answer, "We never worry about drowning worms. They will find dry places to hang out. If she can grow vegetables, the worms will be fine. Fully raised beds (off the ground) do tend to get hot. She should shade it in the summer, but they will probably be fine. The worst thing that might happen is they die over the summer and she has to add more in September when they start getting cooler nights." Hope that helps.

Verry

Tuesday 8th of February 2022

Nice and useful information