Why worm castings?

Worm castings are an all-natural soil amendment made exclusively by composting worms. Unlike other worms that burrow deep in the ground, composting worms stay near the surface, consuming dead or decaying organic material. As they feed, worms leave behind castings packed with nutrients and beneficial organisms plants love. Worm castings look like fine, dark particles of soil, and have a rich, earthy smell. They even feel good in your hands. Pick up a handful and see for yourself!

What can worm castings do for my soil?

Worms are nature’s way of taking care of the soil, and the castings they leave behind are the building blocks of a healthy growing environment. Worm castings provide all the benefits of regular compost and so much more, bringing tired, stagnant soil back to life. Teeming with microorganisms, worm castings put beneficial microbes back into the ground, creating a thriving habitat for all the creatures nature intended healthy soil to contain: good bacteria, fungi, protozoa, actinomycetes, nematodes, arthropods and even insects. This biological activity creates naturally fertile “living soil,” giving plants easy access to the nutrients they need. Worm castings contain large amounts of organic material. Soils rich in organic material have increased water retention and improved aeration. The organic material in worm castings also creates better soil structure to resist erosion and compaction. Worm castings are more than just a temporary fix. The microbe-activated fertility sustains the soil without the need for chemicals or fertilizers. Soil becomes a healthy ecosystem fueled for growing hearty, robust plants all season long. Worm castings build fertility from the ground up, the way nature intended. No other soil amendment does more.

How can worm castings help my plants?

Healthy plants begin with healthy soil. That’s where worm castings have a distinct advantage. Unlike other soil amendments that feed only the plant, worm castings nourish the soil. Many of us have tried to help a struggling plant by adding synthetic fertilizer or other chemicals. This treats the symptom, not the cause. Worm castings go straight to the source, improving soil health so plants can sustain themselves naturally. As soil health is improved, plants can more easily access and absorb the nutrients they need. This results in stronger root development and more vigorous growth. Plants with stronger root systems are better equipped to ward off pests and diseases and tolerate extreme conditions such as severe heat or drought. Castings also supply increased levels of macro and micro-nutrients, plant growth hormones, and beneficial microorganisms, all of which help seeds germinate better, while plants grow faster, with greater yields. Worms are nature’s way of taking care of the soil, and their castings will take care of your plants, providing everything they need to flourish and thrive.

What's so special about worm castings?

It’s all in how they’re made. Worm castings have the distinction of being the only soil amendment that passes through the body of an earthworm. This process provides a host of benefits superior to regular compost or any other product. We like to think of worm castings as nature’s secret weapon. Here’s why. As worms consume organic material, they load it up with all kinds of good things only worms can provide: special growth hormones, plant-boosting enzymes, and beneficial microbes from the worms’ digestive system. The material is also infused with powerful nutrients from the worms’ intestines. Before being deposited into the soil, each casting is coated in humic acid, enclosing the casting to help it retain water. This coating breaks down slowly over time, delivering a steady release of moisture and nutrients. Continuing through the digestive tract, the material is eventually excreted as a worm cast, packed full of all the things plants need to thrive. This transformation from organic material to plant and soil superfood is unlike anything else. Worm castings are biologically and chemically different from either compost or soil. With a much higher percentage of humus, castings not only hold more water, they also provide binding sites for micronutrients such as calcium, magnesium, and sulfur that would otherwise wash out of the soil. Gardeners love that worm castings are naturally infused with a host of beneficial microorganisms. This creates a biologically active growing medium to rebuild soil and give plants a nutritional superboost. Nature has perfected the amazing process of creating worm castings. All natural, full of good stuff, and made only by earthworms. Now that’s special.

What are the vermicast benefits for the soil?

  • Adds organic matter
  • Helps soil absorb and retain water
  • Breaks up clay soils
  • Improves soil structure
  • Eases cultivation
  • Helps form soil aggregates
  • Enhances soil fertility
  • Reduces bulk density
  • Improves soil aeration
  • Increases soil microbial populations
  • Reduces soil compaction
  • Diminishes soil erosion
  • Reduces pH
  • Helps prevent soil crusting
  • Provides micro- and macronutrients and increases their availability

What are the vermicast effects on plant growth?

  • Causes seeds to germinate more quickly
  • Enhances rate of seedling growth
  • Increases root numbers and biomass
  • Improves root stress tolerance
  • Leads to earlier flowering of plants
  • Increases plant yields
  • Decreases plant transplant shock
  • Increases plant vitality and flavor profile
  • More leaves and flowers
  • More total leaf area
  • Greater plant biomass
  • Higher leaf chlorophyll content


Rollover picture to view benefits


Planted at the same time and given equal care, the sprouts on the right have a noticeable head start.


Note also the roots poking through the bottom of the seed tray.

Gives Plants a Head Start


Castings are great for greenhouse plants.


The row in the forefront shows cabbages grown in soil amended with worm castings.


The back row plants, grown without castings, have a lot of catching up to do!

Great for Greenhouse Plants


Worm castings actually help seeds germinate earlier.


It took 11 days for any sign of life in the tray on the left, but only 5 days when the first sprouts appeared in the tray amended with worm castings.

Great for Germination


Instructions for Use

For healthy plants and soil, nothing beats the benefits of worm castings. Castings will not burn the roots of plants and are safe for people and pets. Follow the recommendations below to get optimal benefits from your worm castings.   
  • Planting Vegetables & Flowers
    Place ½ to 1 cup worm castings in the planting hole and mix with soil when the plant is set out.  Side dress around plants during growing season at a rate of 1 inch per plant, or 1 cup per linear foot of row, once every 2 months.

  • Annuals & Perennials
    Mix 1 to 1 ½ cup castings into the soil at the drip line of each plant.  Work gently into the soil. Side dress around plants during growing season at a rate of 1 inch per plant, or 1 cup per linear foot of row, once every 2 months.

  • Germinating Seeds in Containers
    Mix 1 part castings to 4 parts seed starting mix.

  • Planting Garden Seeds
    Line each garden furrow with 1 to 2 inches of castings before planting seeds. Mix lightly into the soil.

  • Potting Container Plants (new)
    Mix 1 part castings to 4 parts soil.

  • Container Plants, Window Boxes, or Hanging Baskets (established)
    Add 1 to 2 inches of worm castings to top of the soil. Mix gently into the soil. Reapply every 2 months.

  • Amending Garden Soil
    Apply 1 to 2” across entire garden, then work gently into the soil.  This equates to about 7.5 gallons per 100 square feet.  Amend again after 2 months.

  • New Lawns
    Apply 10 lb. per 100 square feet.  Work lightly into the soil.

  • Established Lawns
    Evenly distribute as a top dress at a rate of 10 lb. per 100 square feet in early spring and early fall.

  • New or Transplanted Roses, Trees, Shrubs & Berry Bushes
    Mix 1 part castings to 3 parts soil and place in planting hole.

  • Established Roses, Trees, Shrubs and Berry Bushes
    Mix 4 cups castings gently into the soil at the drip edge of the plant at a depth of 2 to 3 inches.

Never let your worm castings dry out.  Mist them lightly with water to keep them moist until ready to use.
This keeps the beneficial microbes alive and happy and ready to go to work for your soil and plants!   



Composting with worms is a sustainable and environmentally friendly way to recycle food scraps and put them to use in the garden.  It’s inexpensive and fun and can be done year-round. 

Worm bins take up very little space and can be located in your kitchen, laundry room, garage, or anywhere that’s convenient. Once your worm bin is up and running, the worms will multiply on their own and their food is free! Your composting worms will eventually turn their food and bedding into an all-natural, microbe-rich soil conditioner packed with plant-boosting nutrients.

Composting with worms requires planning, preparation and consistent care. The instructions below will ensure your worm friends are happy and healthy, with all the right conditions to provide your very own organic plant food.

Materials Needed:

  • Storage bin – 18 to 20 gallon, dark colored plastic (not see through)

  • Drill with 1/4 inch bit – for making drainage and ventilation holes

  • Bedding – shredded newspaper or cardboard, moistened

  • Food – kitchen scraps – see information on what to feed your worms

  • Worms: 1/2 to 1 pound of composting worms (about 1000 worms)


Step-by-Step Instructions:

Step 1:  Prepare the Bin
  • Drill about 20 evenly-spaced 1/4 inch holes in the bottom of the bin. These holes will provide drainage if needed.

  • Drill a row of 1/4 inch ventilation holes about 2 inches apart on all 4 sides of the bin. Drill the holes about 3 inches down from the top of the bin.

Step 2:  Prepare the Bedding
  • Your worm bedding can be shredded newspaper and/or cardboard. Use a shredder or just tear the paper or cardboard into small strips by hand.  A good size to aim for if shredding by hand is 1 – 2 inches wide and 4 – 5 inches long, but it’s ok if the sizes vary.

  • Newspapers should not contain glossy or colored pages, and cardboard should be mostly brown with minimal colored ink or lettering. You can use cardboard from shipping boxes, paper towel or toilet paper rolls, egg cartons, fast food “to go” drink holders, or other sources. Worms especially love corrugated cardboard!

  • Worms need bedding that is moist but not soggy or dripping. Soak the bedding in water for a few minutes and squeeze out the excess.  Thicker corrugated cardboard may have to soak longer to get thoroughly wet.

  • Fill bin about 1/2 to 1/3 full with the moist bedding, fluffed up.

Step 3:  Add food scraps
  • About a week to several days before adding worms, place a small amount of food scraps in each corner of your bin. Banana peels or apple cores are good choices for this. Resist the temptation to add more than just a handful of scraps as you only need a small amount to get things started.

  • Worms’ main source of nutrition comes from the microorganisms that grow on fruit and vegetable waste as it starts to decompose. That’s why it’s a good idea to prepare the bedding and add food to the bin ahead of time. However, if you can’t do this beforehand, don’t be too concerned. Your worms will wait around until there are enough microbes on the surface of the food before they start to eat.

Step 4:  Add Worms
  • Dig down in the middle of the bedding and gently place your worms in the bin. Cover them lightly with the bedding. Worms will burrow further into the bedding as they explore their new home.

  • A good amount of worms for an 18 – 20 gallon bin is anywhere from 1/2 to 1 pound of worms. With the right care, your worms will populate the bin on their own to an appropriate level.

  • Cut a piece of cardboard or black plastic to cover the bedding. Worms do not like light and the covering will help them acclimate more easily. You can put the lid on the bin, but worms also need air flow and they will receive more fresh air without the lid.

  • Leave the worms alone for a few days to settle in before you give them more food. They will feed off the bedding, so they won’t go hungry.

Step 5:  Feed Your Worms
  • Start by feeding small amounts of food. A few handfuls at a time are plenty in the beginning. If there is more food than the worms can consume in a few days, the extra food may start to ferment. Smaller-sized meals will help ensure the worms are able to process all of the food.  As the worms multiply, you can begin to add more food.

  • To kickstart the decomposition process, chop food into smaller pieces. You can also freeze the food scraps. After thawing, drain the excess liquid before feeding.

  • Place the food near the top of the bin and cover it with 3 to 4 inches of bedding. This will to keep it from attracting flies and other pests. Put the food in different sections of the bin each time you feed. This will ensure the worms move around to process all areas of the bin.

  • Take note of the amount of food you provide and how long it takes the worms to consume it. Make sure all of the food is gone before adding more.  Overfeeding is the most common mistake and can lead to fermenting food before your worms have a chance to consume it all.  Fermenting food means a stinky bin! 

Step 6:  Monitor Your Bin

It is important to monitor your worm bin on a regular basis. Red Wigglers are very hardy and will adapt to a variety of conditions, but certain criteria are necessary for your worms to thrive and reproduce.

  • LOCATION – Place your bin in a convenient, well-ventilated area such as a garage, laundry room, covered balcony, deck or porch. You can put the lid of the bin underneath it to protect floor surfaces. You can also keep your bin outside if temperatures permit, but be sure to shield it from hot sun and rain.

  • MOISTURE – The contents of your bin should feel like a damp sponge. Pick up a handful of bedding and squeeze it in your hand. If you can squeeze out only one or two drops of water, the moisture is at an appropriate level.  If you can squeeze out more than a few drops of water, the contents are too wet.  If the contents are too wet, add some dry bedding to decrease the moisture level. If the bedding is too dry, lightly spray or mist with water. Worms breathe through their skin and their skin must stay moist.  Never pour water directly into the bin.

  • TEMPERATURE – Red Wigglers generally prefer temperatures in the 60 to 80 degree F range. They will tolerate temperatures a little higher or lower than this, but not for long.  If the temperature is too hot or too cold, your worms may become less productive and not eat as often or as much.

  • AIR FLOW – Worms need an aerobic (oxygen rich) environment. The holes drilled in the bin will help with air flow, but it is also beneficial to keep your bin in a well ventilated area.  If the bedding gets packed down, stir or fluff up the contents to encourage good air circulation.  Leaving the lid off the bin also helps.

Step 7:  Harvest Your Castings

As your worms grow and do their work, your bin will start to reveal more and more worm castings.  Worm castings (vermicompost) are what’s left behind as worms consume their food and bedding.  They should be brown and earthy-looking and not smell bad.

At around 3 or 4 months, it’s time to harvest the worm castings and give your worms new bedding.  Pour the contents of the bin onto a tarp or piece of plastic and separate the worms from the castings.  Worm castings are packed with plant nutrients and beneficial organisms that will condition your soil and feed your plants. Take advantage of this amazing soil amendment by applying it to houseplants, flowers, vegetable plants, or anything that grows! You may notice that your worms have increased in numbers. They reproduce rapidly when conditions are favorable.  Prepare the new bin, add worms, and you’re off again on the wonderful journey of recycling with worms!



Composting worms are hardy and adaptable little creatures and will tolerate a wide range of conditions. There may be times, however, when you experience a few bumps in the road and things don’t go as planned.  Here are a few of the most common issues and their solutions.

Problem: Worms are crawling out of the bedding and onto the sides or lid of the bin.
Likely Issues:
  • Wet bedding: Bedding should feel like a damp sponge when squeezed.  If you can squeeze out more than one or two drops of water, the bedding is too wet.  Add dry bedding to help soak up some of the moisture, and limit foods with a high percentage of water such as melons.

  • Dry bedding: If the bedding feels dry, mist lightly with water. Place a few sheets of moist newspaper over the bin, and offer more high moisture foods such as melons. Never pour water directly into the bin.

  • Compacted bedding: Tightly packed bedding could cause the contents of your bin to become anaerobic (lacking oxygen).  Worms need an aerobic (oxygen rich) environment.  The bedding should be fluffy and light to allow air pockets to develop throughout the bin.  Gently stir the contents of your bin and fluff up the bedding to facilitate better air flow.

  • Temperature: Your bin may be too hot or too cold. Worms do best in a temperature range of 60 to 80 degrees F.  They will tolerate slightly cooler or warmer temperatures, but only for short periods of time. Make sure your bin is located in an area where an appropriate range of temperatures can be maintained.

Problem: Strong, unpleasant odors coming from the worm bin.
Likely Issues:
  • Excess food: Excess food that has begun to ferment can really stink.  Don’t give your worms too much to eat at one time. Check your bin at each feeding, and don’t offer additional food until the worms have consumed what they have.

  • Too much moisture and not enough air flow: When moisture and oxygen levels are not in balance, neither are the types of bacteria living in your worm bin. Worms are known for producing castings that contain good bacteria, and this good bacteria does not have an unpleasant smell.  With too much moisture and not enough oxygen, however, anaerobic bacteria move in, and so does the stink. Invite more good bacteria by adding materials to your bin that promote aeration and drainage such as composted leaves, dry grass clippings, or more shredded newspaper/cardboard. Gently stir the contents of your bin to increase air flow.  Temporarily remove any covering you may have on the bedding.

Problem:  A lot of liquid is seeping from the bottom of your worm bin.
Likely Issues:

Leachate go away! Excess moisture seeping from the bottom of your bin is not a desirable product of a well-managed worm bin. Called “leachate,” this excess moisture is NOT worm tea. Leachate indicates too much watering, too much feeding, or not enough bedding added in relation to food added. Leachate does not get cleaned by passing through the worms’ digestive system, so it may contain toxins. Feed less food, less frequently, and make sure all food has been consumed before adding more. Limit foods with a high percentage of water, such as melons. You can also add dry bedding to balance out the excess moisture.



If worms could talk, they would tell you their favorite foods are fruits and vegetables. Include the skin or peelings on all fruits and vegetables as worms love this part of the meal.  Worms also enjoy used coffee grounds and crushed eggshells, so offer these when you can.

Remember that worms love shredded newspaper and cardboard. Corrugated cardboard is their favorite and you can’t have too much of it. Don’t forget to soak it in water before giving it to your worms.


Here’s a sample list of foods to encourage and satisfy your worms’ appetite.

What to feed worms.png
Worm foods to avoid.png

Citrus foods such as oranges, lemons, pineapple, grapefruit and tomatoes are not good choices either, as worms don’t like them and they can also make your bin too acidic. I also don’t feed hot peppers.

How Much and How Often Should You Feed Your Worms?

No set formula exists for feeding, but all experts agree on one thing:  DO NOT OVERFEED YOUR WORMS.

A general guideline for a new bin is to feed no more than 1/4 the total weight of the worms in the bin at each feeding.  For example, if your bin has a pound of worms, begin by feeding 1/4 of a pound of food.  As your worms get established and start to multiply, you can gradually add more food.

Chopping the food into smaller pieces increases the surface area of the food and speeds up decomposition. You can also freeze your food scraps as freezing causes the food to decompose faster when thawed.

Use common sense when balancing the amount and frequency of food. Inspect the bin before each feeding, and if there is uneaten food left in the bin, do not add more.  Food that your worms cannot consume in a few days may start to ferment and result in a smelly bin.  Remember that your worms will also be munching happily away on their bedding of shredded newspaper and cardboard so your worms will have plenty to eat.



Size Matters

You will be much better cushioned against your own errors with a more expansive environment where worms can better escape the effects of overfeeding, overwatering, under watering or other errors you may make at first. Think of worm bin size as a buffer against bad things happening.  An 18-gallon tote is a safe size for beginners.

Air Matters Too

Worm composting is an aerobic process and the quality of your castings is strongly correlated to maintaining highly aerobic conditions in your bed. If the bedding in the bin becomes packed or condensed, chances are there is not enough air getting to the worms or to the bedding material.

Don’t Feed Every Day

The worms will do just fine with a feeding every few days and if you happen to even go a couple weeks without feeding, any negative effects are far less than what will happen if you overfeed them.

Remember to Keep Adding Bedding

You can never have too much bedding.  While it’s not necessary to add bedding with every feeding, you should add material such as shredded paper, cardboard, shredded leaves, and maybe even wood chips from time to time.  Adding bedding helps encourage appropriate moisture levels as well as maintaining aerobic conditions in your bin.

If you have further problems or issues you can’t resolve, please contact us!  We’re always glad to help!