Spray & Grow Mushroom Kit FAQs

Spray & Grow Kits are beginner-friendly indoor mushroom growing kits made by North Spore. Inside each box is a fully colonized mushroom substrate block that is ready to produce mushrooms. You simply open the front of the box, cut an X in the plastic bag, mist it regularly and wait for your mushrooms to appear.

Not at all. These kits are specifically designed for beginners. The mushroom mycelium has already colonized the growing medium, so most of the complicated part has already been done for you.

We offer Lion's Mane, Blue Oyster, Golden Oyster and Pink Oyster Spray & Grow Kits. Each produces a different-looking mushroom with its own flavor and texture.

View all Mushroom Kits →

Each kit includes a ready-to-fruit mushroom block inside its growing bag, the Spray & Grow box, a spray bottle and growing instructions.

The growing block is made from mushroom substrate that has already been fully colonized by mushroom mycelium.

Yes. North Spore's Spray & Grow mushroom kits are USDA Certified Organic.

Usually, no — that's the mycelium!

Mushroom mycelium often looks like a soft white or fuzzy coating over the substrate. This is completely normal and is actually what you want to see. The appearance of mycelium varies between mushroom varieties, so some kits may look whiter or fuzzier than others.

Yes. For the best experience, we recommend starting your kit soon after it arrives. The mycelium inside is a living organism and may continue developing even while the kit is stored.

Yes. If you aren't ready to start immediately, North Spore recommends storing the kit in a cool, dry place away from direct sunlight or refrigerating it for up to 6 months.

Because the kit is alive, we still recommend starting it sooner rather than later whenever possible.

No. Occasionally an especially vigorous kit may begin producing mushrooms inside the bag before you activate it.

If you can easily reach the mushrooms, remove them and compost them, then set up the kit normally following the instructions. The block can still produce another flush.

Remove the perforated front panel of the box to expose the plastic growing bag. Cut an X through the exposed plastic, leaving the four plastic flaps in place. Mist the exposed area well and place the kit in a suitable location.

A kitchen counter is often ideal. Choose a spot with indirect natural light, normal air circulation and easy access so you remember to mist it regularly.

Avoid direct sunlight, hot windows, heaters and dark enclosed cupboards or closets.

Mist the cut area of the bag regularly so that it stays damp. Around 5–10 sprays per watering session is a good starting point.

If the surface is drying out before your next misting, spray more frequently or use a little more water each time. Homes with air conditioning or very dry air may require extra attention.

Regular tap water is fine for misting Spray & Grow mushroom kits. Fill the included mister and keep it somewhere close to the kit so daily spraying is easy to remember.

Yes, but they don't need intense sunlight like vegetable seedlings. Normal indirect natural light helps mushrooms develop properly.

Avoid keeping the kit in a completely dark cupboard or closet, and don't place it in strong direct sunlight where the block may dry out.

Mushrooms prefer humid conditions. Regular misting is often enough, but air conditioning, heating or a naturally dry climate can cause the exposed surface to lose moisture too quickly.

If the block repeatedly looks dry or young mushrooms begin drying out, a humidity tent can help.

A humidity tent is a loose, clear plastic bag placed over the kit to help retain moisture around the growing mushrooms.

Don't seal the kit tightly. Mushrooms also need fresh air, so leave plenty of space around the bottom or make several openings in the bag for airflow.

Most kits begin forming small mushrooms, known as pins, within approximately 6–10 days after activation. Once pinning begins, growth can be surprisingly fast and the first flush is often ready only a few days later.

Growing speed varies with the mushroom variety and the temperature and humidity in your home.

Pinning is the stage when the first tiny baby mushrooms begin appearing from the growing block. Once you see pins, keep the area humid and check the kit frequently — mushrooms can grow very quickly from this point.

Many Spray & Grow Kits produce their first full flush in about two weeks. Once baby mushrooms begin forming, they may reach harvest size within only a few days.

A flush is one crop or wave of mushrooms produced by the block. Your first group of mushrooms is your first flush. After harvesting, the block may rest and then produce another flush.

It can. North Spore guarantees the first flush, but with good care many kits produce a second or even third flush.

Later flushes are usually smaller because the fungi gradually use the nutrients contained in the growing block.

Remove your mature mushrooms cleanly from the block, then continue caring for the kit according to the instructions. It may rest for a while before beginning another fruiting cycle.

Don't assume the kit is finished just because nothing happens immediately after the first harvest.

First, give the kit enough time. Pinning commonly takes around 6–10 days and may take a little longer depending on conditions.

Make sure the exposed area is staying damp, the kit isn't in direct sunlight, and there is normal fresh-air circulation around it. If your home is particularly dry, try adding a humidity tent.

The environment is probably too dry. Increase misting and consider adding a humidity tent to keep more moisture around the developing mushrooms.

Long, stretched or stringy mushrooms can be a sign that they need more fresh air. Move the kit somewhere with better natural air circulation, while still keeping it humid and away from direct sun.

Very pale mushrooms may need a little more indirect natural light, or they may simply be getting past their ideal harvest stage. Keep the kit somewhere that receives normal room light without direct sun.

Yes. North Spore provides a grow guarantee for the first flush of its Spray & Grow Kits when the kit is cared for according to the instructions.

If you're concerned about your kit, use the live chat on our website and send us a few clear photos. We'll help you determine what you're seeing and point you in the right direction.

Mushroom Kits purchased through our Tower Garden link are fulfilled and shipped by Tower Garden rather than from the Living Towers farm in Florida.

They are purchased separately. Our seedlings and the growing supplies we stock are shipped directly from our Florida farm, while Mushroom Kits purchased through our website are purchased from and fulfilled by Tower Garden.

You can keep the Living Towers page open while completing your Tower Garden purchase, then return to us for seedlings and other supplies.

Shipping charges for Mushroom Kits are calculated by Tower Garden during checkout.

Tower Garden and Mushroom products fulfilled by Tower Garden generally leave their Memphis warehouse within one to two business days. Your exact delivery time will depend on the destination and shipping service.