All in One Grow Guide
Step One: Inoculation
Choose a Spore Syringe or Liquid Culture
Choosing Between Spores and Liquid Culture
To get started, you’ll need either a spore syringe or a liquid culture syringe of your chosen mushroom species (sold separately).
Spore syringes contain mushroom spores, which need to germinate before they produce mycelium.
Liquid culture syringes already contain live mycelium suspended in a nutrient-rich liquid, ready to get growing.
While both options can work, we highly recommend liquid culture syringes if you want faster, more reliable results. Because the spores in a spore syringe still need to germinate, there’s a higher chance of contamination or slower growth compared to liquid culture.
A Note on Using Spores in All-in-One Bags
Some people choose to inject spore syringes directly into an all-in-one grow bag. And yes – it can work. But it’s a little like skydiving with a parachute you stitched together at home: exciting, but not the safest route.
Why? Spores are naturally “dirty” – they come straight from nature and often carry extra microorganisms along for the ride. Skipping steps like germination and culture testing means you’re rolling the dice with contamination.
If you’re serious about reliable, high-yield harvests, starting with liquid culture is the smarter, smoother option. Think of it as giving your mushrooms a head start – fewer risks, faster colonisation, and a much higher success rate.
Attach The Needle
Preparing Your Syringe
Take your spore or liquid culture syringe and give it a good shake for around 10 seconds – this helps evenly distribute the contents.
Unscrew the protective cap from the syringe.
Attach the sterile needle securely to the syringe tip.
⚠️ Important: Leave the needle cover on for now. Don’t remove it until you’re ready to inoculate – this keeps everything sterile and contamination-free.
Time to Squeeze!
Next, unfold the bag and squeeze it gently to mix up the substrate inside.
Let's Introduce Air!
Aerating the Bag
Hold your grow bag from the top (just below the seal) for around 2 minutes. As you do this, fresh filtered air will naturally be drawn in through the white filter patch.
💡 Pro Tip: Mycelium is alive – just like us, it needs oxygen to thrive. By gently drawing in air before inoculation, you’re giving your substrate a boost of fresh oxygen, which helps speed up colonisation and supports strong, healthy growth.
⚠️ Important: Don’t remove the filter patch or open the bag. The patch is specially designed to allow air exchange while keeping contaminants out – it’s your mycelium’s personal air vent and protective barrier in one.
Sanitise the Injection Port
Wipe down the rubber injection port thoroughly with the alcohol swab provided.
Time to Set the Spores Free!
For best results, use 5ml of solution for a 1.5kg bag and 10ml for a 2kg bag.
Remove the protective cover from the syringe needle.
Immediately pierce the sanitised injection port with the needle, applying gentle pressure.
Slowly depress the plunger to inject your solution into the bag.
Carefully withdraw the needle from the port.
💡 Saving leftover solution: If you have any left in the syringe, simply replace the needle cap and store it in the fridge. Properly stored, your culture can remain viable for 6+ months.
🎉 That’s it – inoculation complete! Your bag is now ready to move on to incubation, where the mycelium will begin its journey of colonisation.
Step Two: Incubation
Incubate the Bag
Place your inoculated bag in a dark, warm spot to allow the mycelium to establish itself.
🌡️ Optimal temperature: Keep the environment between 24–27°C for steady, healthy growth.
⚠️ Important: Avoid going above 27°C. Higher temperatures can stress the mycelium and create ideal conditions for contamination – not what you want at this stage.
Think of incubation as giving your mycelium a quiet, cosy space to do its work. With the right conditions, you’ll soon see the first signs of colonisation spreading through the bag.
Initial Colonisation
After about a week, you should start to see the first signs of colonisation. Healthy mycelium should appear first as fluffy white specs on the substrate.
It can sometimes take longer than a week, so don’t be disheartened if it does.
PRO TIP – Depending on the genetics, strain or species of mushroom you are growing, colonisation times can vary. It some cases, it can take up to 2 or 3 weeks to see the first signs of colonisation. This is especially true if you’re using a spore syringe, so be prepared to wait.
Mid Way!
Over the next 2–3 weeks, you’ll see white mycelium spreading throughout the bag as it colonises the substrate. This is exactly what you want to see – a healthy sign that your culture is thriving.
When around 30% of the substrate looks colonised, it’s time to give your mycelium a helping hand:
Gently break apart the colonised sections inside the bag.
Mix them evenly through the uncolonised substrate.
💡 Why this matters: Breaking and mixing distributes the mycelium more evenly, giving it extra inoculation points. This can dramatically speed up colonisation, helping the entire bag establish itself faster and more consistently.
Full Coloniation
Within about a week or so after mixing, your mycelium will finish colonising the bag. The substrate will transform into a solid white block – this is your fruiting block.
This block is the foundation your mushrooms will grow from, so reaching this stage means you’re right on track. Think of it as the mycelium knitting everything together into one strong, nutrient-rich base, ready to start producing mushrooms.
Step Three: Fruiting
PRO TIP!
Once your block is fully colonised, it becomes much more resistant to contamination. By this stage the mycelium has strengthened and created a protective network, which is why it’s safe to now expose it to open air.
That said, clean handling is still important. While the risk of contamination is lower, best practice is to wash your hands, keep tools sanitised, and avoid unnecessary contact with the block. A little extra care at this stage goes a long way in supporting healthy, abundant mushroom growth.
Remove the Cake From the Bag
When your substrate is fully colonised, it’s time to carefully remove it from the bag.
Using clean, sanitised hands (or gloves), gently cut open the grow bag.
Peel the plastic away and lift out the solid white fruiting block.
⚠️ Handle with care: The block is firm but still delicate. Avoid squeezing or breaking it apart – treat it gently so the mycelium stays intact and ready to fruit.
Move to a Fruiting Tent
Once removed from the bag, carefully place your colonised fruiting block inside a fruiting tent or grow chamber.
✨ Cleanliness matters: Always wash your hands thoroughly (or wear sterile gloves) before handling the block, and set it up in a clean area to give your mushrooms the best possible start.
This step marks the transition from incubation to fruiting conditions – your block is now ready to begin producing mushrooms.
Give Some Ambient Light
You do not need to overthink lighting as mushrooms require very little, but some is always beneficial.
Fill a clean mister bottle with tap water.
Lightly mist the inside walls of the fruiting tent until you see a fine layer of condensation. (Avoid spraying the block directly – too much moisture on the surface can slow things down.)
Close the tent securely with a paperclip.
Place the fruiting tent somewhere warm, ideally between 21–24°C.
Make sure the block receives 4–6 hours of indirect sunlight or room light each day.
💡 Tip: Mushrooms don’t need much light – just enough to help them orient themselves. A little indirect natural light or standard room lighting is perfect.
Get Misting!
During the first flush (crop), your fruiting block will need very little extra care. In most cases, a single misting on the inside walls of the fruiting tent is enough to keep humidity at the right level.
If the substrate looks a little dry or you notice there’s no condensation inside the tent, you can lightly mist the walls again every couple of days.
⚠️ Important: Avoid letting water pool at the bottom of the tent – standing water can encourage bacterial growth. If it does collect, carefully tip the tent to drain it away.
Think of this stage as a balancing act – you want steady humidity without drowning your setup. A light touch works best.
It's Pinning Time!
Around 14–21 days after spawning, you should notice your very first pins appearing. These tiny white bumps are baby mushrooms – the early signs that your hard work is paying off.
Over the next few days, those pins will grow and develop into mature fruiting bodies, ready for harvest. This is one of the most exciting stages of the process – your block is alive and thriving, and mushrooms are officially on the way.
Step Four: Harvesting
Harvest Time
Pick your mushrooms just as the veils beneath the caps begin to break away from the stem. This is the point where they’re at their best – firm, fresh, and ready to enjoy (if you’re cultivating gourmet species).
Once you’ve harvested, give your fruiting block a reset by misting it directly for around 1 minute. This rehydrates the block and prepares it for the next flush.
From here, simply repeat your fruiting steps (1–5) to encourage more crops. With the right care, your block can deliver multiple flushes, each producing fresh, healthy mushrooms.
Multiple Flushes
Each fruiting block typically produces 2 to 3 flushes (crops) of mushrooms. So don’t be tempted to throw it out after the first harvest – there’s usually plenty more to come!
Your grow is complete once the block stops producing mushrooms, or if the substrate eventually shows signs of contamination. At this point, the nutrients have been spent and the mycelium has done its job.
♻️ Disposal tip: A finished block makes great compost. Simply break it up and add it to your compost heap or garden soil to recycle the nutrients back into nature.
Well Done – You Did It!
Congratulations – you’ve just completed your mushroom grow! From inoculation to harvest, you’ve guided your mycelium through its full life cycle, and now you’ve experienced the reward of fresh, home-grown mushrooms.
Whether this was your very first attempt or you’re already hooked, every grow teaches you something new. And the best part? You can take what you’ve learned and apply it to your next project, experimenting with different species, methods, or yields.
At OnlySpores, we’re here to support you at every stage. From sterilised grain spawn and bulk substrates, to our beginner-friendly All in One Kits and advanced Monotub Systems, we’ve got everything you need to keep growing with confidence.
🌱 Ready for round two? Explore our full range and take your mushroom cultivation journey even further.
