How to Grow Mushrooms in Buckets and Containers
You don’t need a giant forest or a big backyard to grow mushrooms. They can thrive right on your countertop or patio! Mycology enthusiast and mushroom expert Logan Hailey explains nine simple steps to growing mushrooms in containers or buckets.
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Fungi are a mystery to most, but they can be grown much like crops in our gardens. Better yet, you can cultivate tasty edible fungi indoors in containers. From lion’s mane to blue oysters to shiitakes and beyond, there are many beginner-friendly mushrooms suitable for growing on your countertop.
All you need is quality mushroom spawn (a substrate like straw that is colonized with fungal mycelium), the right container, humidity, water, and light. Some kits even include everything you need in one streamlined box.
Let’s dig into the nine simple steps to growing mushrooms in containers and buckets.
Can You Grow Mushrooms in Buckets?
Buckets are one of the easiest ways to grow mushrooms quickly in a small space. This beginner-friendly method includes five-gallon plastic buckets with holes in them. They are filled with a pasteurized organic substrate, such as straw or wood chips, then inoculated with the desired fungal spawn.
The inoculated substrate is left to colonize the bucket in a dark, humid place until mushroom fruiting begins in 10-21 days. Depending on the species, you may enjoy harvests within a few weeks, and some buckets continue producing secondary and third flushes of mushrooms!
Here are some suitable mushrooms for growing in containers and buckets:
- Lion’s mane
- Chestnut
- Shiitake
- Blue oyster
- Pink oyster
- Italian oyster
- King trumpet
9 Steps to Grow Mushrooms in Containers and Buckets
Growing mushrooms in buckets is easier than you may think. But if you want the simplest, quickest method for harvesting your own edible fungi, try an all-in-one kit or grow bag from North Spore. For longer-lasting, more affordable harvests, follow these steps to cultivate your favorite species in straw or wood chips inside different plastic containers.
Gather Supplies and Prepare Bucket
The basics for growing mushrooms are probably already in your garden, but you will need to purchase spawn and hydrated lime to inoculate the medium.
Here are the main supplies you’ll need:
- Five-gallon plastic bucket with a lid or other sealed plastic tubs and containers
- ½” drill bit
- Chopped straw or a leaf mulcher to shred straw
- Large plastic bin or tote
- Heavy weight, such as a cinder block
- Mushroom spawn of desired species
- pH meter
- Calcium hydroxide (hydrated lime)
- Weighing scale
- Ten-pound mesh bags (from onions or potatoes)
- Rubber gloves
- Trash bag (not clear) or grow tent
To begin, ensure your five-gallon bucket is clean. Contamination is the main cause for failure because other microbes can outcompete your desired fungi. Wash the bucket with hot water and soap, then optionally wipe down with an alcohol swab.
Next, you’ll need holes around your bucket where the mushrooms can sprout from. Use the ½” drill bit to drill holes around the entire circumference. A diamond-shaped pattern allows enough airflow and space for fruiting. Don’t use a larger drill bit because large holes can dry out the substrate.
Choose a Substrate
Mushrooms grow from a root-like system called mycelium. This intricate network of fungi requires decaying or dead organic matter to properly colonize and grow. The dead or decaying matter is also known as substrate, and you can think of it like the food for the fungus.
Carbon is an essential material in the substrate that feeds the fungus. Research shows that the most effective substrates are:
- Straw *most ideal for oyster mushrooms and other homegrown species
- Sawdust
- Wood pellets
- Coffee grounds
- Manure
Our clean shredded straw mulch is the most beginner-friendly option if you don’t have a leaf mulcher. If you want to use straw from a feed store, lay it out on the ground and use a lawn mower to chop and shred it into smaller pieces.
Pasteurize Substrate
The next step is pasteurization. You may have heard the term “pasteurization” used to describe pasteurized milk or cheese. The pasteurization process uses heat and minerals to kill off rival bacteria and mold that may compete with your mushrooms. You will need your clean plastic tote or trash bin, hydrated lime, and pH meter for this step.
To pasteurize straw or another substrate:
- Fill the large tote or trash bin with water
- Slowly add hydrated lime, about 6 grams lime per 1 gallon of water
- The goal is to use the lime to increase the pH from neutral to 12.5
- Stir the water with a large wooden paddle or spoon
- Stick the pH meter in the mixture to measure the pH level as you add more lime
- Wait for the meter to read 12.5 pH
- Fill clean 10-pound mesh onion or potato sacks with straw
- Weight them on the scale and note the weight of each dry sack (you will need the weight to calculate the moisture content of the pasteurized straw in a later step)
- Submerge the onion bags into the water-lime mixture
- Weigh down with a cinder block or other weight
- Keep the bags of straw submerged overnight (at least 12 hours)
Drain Substrate
When the overnight pasteurization process is complete, you can remove the straw bags from the water and hang them up to drip dry for 12-24 hours. Most mushrooms prefer a substrate moisture level of around 50%. Overly wet straw can cause a growth of unwanted bacteria or mold. However, if the straw substrate is too dry, your desired fungi will struggle to colonize it and produce mushrooms.
Weigh the straw bags on the scale until they are twice the dry weight. In other words, if your bag of dry straw was originally 2 pounds, let it drip dry until it weighs about 4 pounds. This is a sign that the moisture level is right and you can start inoculating.
Inoculate Your Bucket (Add Spawn)
Inoculation is a fancy word for introducing a microbe to a place where it can grow. In this case, your microorganism is a mushroom-producing fungus. The fungus arrives in a handy ready-to-add spawn that already contains established mycelium and substrate. In other words, the spawn is sort of like a vegetable seedling; it already contains the vegetative “roots” needed to initiate growth.
Before you inoculate, ensure that you wipe your buckets with 70% isopropyl alcohol in the first step. Alternatively, dunk them in a water solution with some bleach. Next, you’ll mix the spawn and pasteurized straw together in alternating layers.
For a five-gallon bucket, use about five pounds of sawdust spawn. You can use half this amount per bucket if desired, but less spawn means less reliable colonization. Beginners should usually use more spawn rather than too little. This ensures that the fungus can quickly and effectively colonize the substrate in your bucket.
As you fill the layers, use about 1.5 inches of pasteurized straw on top of each thin layer of spawn. Repeat until you fill the entire bucket. If you have extra spawned straw, add it to a smaller container like a tupperware, bag, or milk carton to see if you can get an extra flush of mushrooms.
Place in a Dark, Cool Place
Place the lid on your bucket and move out of direct sunlight. Unsurprisingly, mushrooms need darkness to colonize the substrate and start growing. A basement, closet, or cool garage is ideal.
Aim for temperatures between 30-75°F (-1-24°C), but check the specific temperature requirements of each species. For example, cold-tolerant blue oysters like to grow in environments close to freezing, but pink oyster mushrooms do best around 60°F (16°C) or warmer.
It’s very important that the bucket does not dry out as it is colonized. Place an opaque trash bag or grow tent (used by many indoor growers) to increase the humidity in and around the bucket.
Check if Colonization Was Successful
On average, the fungus may take 10-21 days to colonize a bucket. You can check it regularly throughout the week to see if colonization is successful. Some mushrooms have a sweet anise smell that can be a positive sign of colonization. You should also see white mycelium growing on the straw.
The most obvious sign of colonization is pins—small white clusters of mushroom structures—that poke through the bucket’s holes.
The bucket may feel warm to the touch as the mycelium grows. Avoid placing too many containers close together because excess heat could kill off the establishing fungi. If you notice a foul smell or fungus gnats flying around the buckets, this could be a sign of contamination or improper moisture content. Monitor closely, and if you can’t see any cobweb-like white mycelium, you may need to start over.
Mist and Wait for Fruiting
Mushrooms can take about ten days to grow from a pin to a harvestable-sized mushroom. Once you see the pins forming, move the bucket to a shady outdoor or indoor space like a shaded deck, shed, or garage.
The most important thing to remember during this phase is to keep the mushrooms moist. Use a mister bottle to regularly mist the pins and maintain humidity. Do not let them dry out, or they may not grow into full-size mushrooms.
The ideal temperature during fruiting is 50-80°F (10-27°C) and 50% or greater ambient humidity.
Harvest and Enjoy
Finally, it’s time to pick some mushrooms! Depending on the species, your mushrooms may be shaped differently. Oyster types expand and curl their cap edges upward, indicating that they are about to release spores. The best time to harvest is right before spore production.
Use a sharp knife to cut an entire cluster off at the base. Slice right against the bucket. Cook right away or store them in a paper bag in the fridge for up to a week. You may get another flush of mushrooms if the bucket stays in a shady, humid area. Once the substrate is exhausted, dump the bucket of straw out in your veggie garden or yard to nurture the soil with beneficial fungi.
