How to Get More Life From Your 'Spray & Grow' Mushroom Kit

Our Spray & Grow Kits are an easy and convenient way to start growing mushrooms. After they’re done fruiting on your kitchen counter, there are a few ways you can reuse your kit and keep on growing! Sometimes a little fresh air is all that a kit needs to be revitalized.

Louis demonstrates some of our favorite ways to reuse Spray & Grow Kits in the video below or read on for walkthroughs.

The simplest way to encourage more fruitings is to move your kit outdoors. A change in environment or temperature shift can sometimes be a cue for fungi to produce more mushrooms.

1. Take the mushroom block out of the box (and recycle the box!)
2. Leave the block in the plastic bag
3. Place the block cut side up in a shady area where it will receive rainfall
4. Check on the block periodically, especially after rain or humid days

Leaving the plastic on your kit helps to keep moisture in, preventing the block from drying out. Feel free to spray it periodically when it’s looking parched as you would inside. After a couple of weeks, you should expect mushrooms after heavy rainfall or after a big temperature shift.

We like to put our kits under cover of fern fronds. The vegetation creates a humid microclimate for fungi to thrive.

Pink oysters like it hot - these mushrooms won’t fruit outside unless temperatures are above 70 degrees.

Do you have a shovel and a little bit of outdoor space? Then this next method is for you! And it’s sure to turn some heads when mushrooms clusters pop out of your garden or lawn.

1. Take the mushroom block out of the box (and recycle the box!)
2. Remove the plastic bag
3. Dig a hole the size of the block in a shady area
4. Tuck the block into the soil
5. Cover the block with 1” of soil or mulch
6. Water as you would the plants in your garden
7. Check on the block periodically, especially after rain or humid days

Burying the mushroom block helps protect it from the elements, and the fungi can wick moisture from the nearby soil. Adding a little mulch or soil on top also gives the block a buffer from direct sunlight. With any luck, your block will fruit in a couple of weeks! You can even try burying different types of blocks next to each other as a feature in your landscape. Imagine bright mushroom bouquets bursting from the ground!

If you’re feeling creative, you can use your Spray & Grow Kit like you would spawn, and inoculate some containers! This process works best with oyster mushroom kits that are hydrated well or have recently fruited. After digesting most of the block’s food, the hungry mycelium will happily jump to more substrate.

You’ll need a few extra materials for this method. First, you need something for the fungi to grow on and eat; we call this a substrate. Chopped straw is ideal because of the smaller particle size, making it easier for the mycelium to jump from piece to piece- like crossing a bridge. Other clean agricultural by-products may be used too, but we find the most success with straw.

Then, you need a container to hold the mix. Airflow is important; choose a container with plenty of holes like a hamper, plastic gardening pot, or bucket drilled with holes. Lids are optional! You will also need a vessel for soaking your substrate and a weight of some sort to keep it submerged. Any pot or bucket or tub will do. We used bricks and an old grill rack, but make use of whatever you have on hand. In a pinch, bags filled with water work really well as weights!

1. Gather your materials and get set up
2. Soak your substrate for 20 min - 1 hour or until fully saturated
3. Let excess water drain off your substrate
4. Measure for ideal hydration by squeezing the substrate in one hand - only a drop or two should drip out. Adjust hydration if necessary
5. Alternate layers of the substrate and the crumbled up mushroom block, leaving the top and bottom layers substrate
6. Lightly compact the straw, especially if it’s not chopped, to remove large air pockets
7. Place it in a shady or semi-shady area and water as you would your plants

Depending on how big your container is and environmental factors like temperature and humidity, your container could produce mushrooms in a month or two. This method takes a bit longer than the previous two because the fungi have all of that new material to consume before they’re ready to flush. But that added material also means the possibility of more mushrooms! Just make sure the containers stay properly hydrated. You don’t want them to dry out, nor should they be soggy.

The last method is very similar in concept to the container method. By using the Spray & Grow Kit like spawn, we can inoculate mulch in the style of mushroom beds. If you have some perennials, trees, or even a garden you’d like to mulch in, this is an excellent method for incorporating mushrooms.

You can inoculate established mulched beds or start new ones, though we’ve found using fresh mulch inoculated with oyster kits to be most successful. More mature mulch may already have some fungal inhabitants that can compete with the inoculum. And that’s where oysters come in, as perhaps the most vigorous fungi that we cultivate. These resilient fungi can handle some environmental stressors, often out-growing potential contaminants. If you’re inoculating established beds, we recommend adding some fresh mulch to the mix to hedge your bets. And feel free to use straw or wood chips as your mulch!

1. Gather your materials
2. Spread an even but light layer of mulch around a shady area to inoculate
3. Spread the crumbled block evenly on top of the mulch
4. Keep alternating layers of the mulch and the crumbled up mushroom block, leaving the top layer as mulch OR mix the mulch and block with your hands and cover with a top layer of mulch
5. Water the patch generously to get it hydrated
6. Keep an eye on the patch and don’t let it dry out - water as needed

Similar to containers, this method may take longer to be fruitful. Expect to wait 1-3 months depending on temperature, moisture, and total volume inoculated. Warm and humid weather with smaller volumes may produce faster if kept properly hydrated.

We hope you enjoy reusing your Spray & Grow Kit. If you tried any of these techniques, congrats on growing outside! Using your Spray and Grow Kit to inoculate containers or mulch is just like using grain spawn or sawdust spawn for those methods. If you’re curious about some other ways to get started growing outside, check out our articles on gardening with mushrooms, building mushroom beds, or log inoculation.

Good luck and spread the spore!