Growing Morel Mushrooms

Mushrooms, in general, are extremely difficult to grow, and cultivating morels is even more difficult. Mushrooms aren't like your standard house plants which can happily sit on the windowsill; mushrooms need a lot more attention. Most notably, mushrooms thrive where temperature and humidity are well-controlled. It is quite an effort to get started but once you get into the swing of things, it is all pretty straightforward.

The first thing you have to do is either buy a morel mushroom kit from a reputable supplier or find some mushrooms in the forest. Morel mushroom kits mainly consist of pre-inoculated mycelium, all you need to do is add water and place it in an area where you can monitor and control the humidity and temperature.

If you want to grow them from the ones you have picked make sure you keep them fresh by putting them in the fridge. Next, you must create a sterilised area, preferably under a HEPA hood, and follow these steps: 

1. Use a sterile paper clip or a needle to pierce the stem of a healthy-looking mushroom.
   
2. Hang the mushroom by the sterile metal over a freshly prepared petri dish (you can obtain these online).
   
3. Let the morel drip its spores onto the Petri plate as you gently work it with your fingers. If you don't see spores falling, just leave the mushroom hanging over the agar and they should fall naturally if you still do not get any spores falling flick or shake the cap to help them fall.
   
4. Cover and seal the agar plate and store it (at 55-80°F). You can invert it to prevent moisture from building up on the lid. After a period of from a few hours to a few days, the spores will begin to send out their first mycelial strands into the agar plate
   
5. The strands will form a web, and then grow vigorously, extending over the entire plate, this is the start of the mycelium. For maintaining rapid growth as we transfer to new media, the most valuable portion is the outer, leading-edge where thin strands are extended most quickly.
   
6. When the plate is fully colonized, i.e. covered completely in white mycelium, you will need to transplant sections into fresh agar, thereby propagating the culture indefinitely, otherwise, you can innoculate grain media with sections of the mycelia you cut from the plate, using a sterilized (alcohol or heat-treated) razor knife. Resterilize the knife after each transfer.
   
7. A good grain medium is annual ryegrass seed or vermiculite covered in brown rice flour. Other grains such as rapeseed, hemp seed, birdseed, and rice will work. Cover grain with water and soak for 24 hours.
   
8. Drain and mix with potting soil, 1 part potting soil to 5 parts grain. Place 2 cups of this medium into a 1 quart regular canning jar.
   
9. Make sure everything is sterile, I like to work with a fan pushing air towards me as this act like a laminar flow. Shake the jar to thoroughly mix in the mycelium. Place the jar in a cool (68 - 71°F), dark place for approximately 4 - 6 weeks. Good growth will be indicated by whitish strands of mycelium growing through the medium. At about 5 weeks, small aggregates of white to rust coloured mycelia sclerotia will form.
   
10. After the sclerotia are visible within the jars, prepare some clean trays to receive the mixture for fruiting. Construct a fruiting room where temperature, humidity, light and fresh, filtered, air can be precisely controlled.
    
11. Make a fruiting substrate mix of 20% sand, 30% potting soil, 50% organic material composed of 80% small hardwood chips (ash, oak, maple, beech, elm, apple, etc.), 10% rice hulls, 5% soybean meal, 5% sphagnum, and a small amount of lime (the mineral, not the fruit) to bring the pH to 7.1-7.3 or buy a premixed version online, make sure it is mixed well.
    
12. Fill an autoclavable aluminium tray (i.e. like a cake pan) or plastic dishpan (liberally punched with drainage holes) to a depth of 2 inches with the substrate.
    
13. Soak the substrate thoroughly with water and then allow to drain completely so that there are no drips. Fill a second, identical tray with soaked, drained ryegrass seed to a depth of 1/2 - 1 inch. Set substrate tray into rye seed tray so that the bottom of the substrate tray rests on the rye seed. Place the prepared trays inside an autoclave bag (oven cooking bags seem to work well) fitted with a filtered closure and sterilize at 15 psi for at least one hour.
    
14. In a clean draft-free area (fan recommended) open the cooled substrate bag and mix ca. 1/2 cup spawn into the substrate using a flame-sterilized spoon. Reclose bag and place in a cool (65-70°F) dark place for 4-6 weeks. During this period (the spawn run) the relative humidity should be kept at 90-100%, CO2 at 6000-9000 ppm, and no fresh air exchanges.
    
15. After 4-6 weeks, the surface of the substrate should be covered with sclerotia. The hard sclerotia lumps are the secret to growing morels. These are the "seeds" of your mushrooms. Keep unused spawn refrigerated at 38-40°F. Spawn is viable for up to a year, under optimal conditions.
    
16. At this point it is super important to chill the mix: After spawn run, remove the rye seed tray from the bag, reclose, and place the bagged substrate tray into refrigeration (38-40°F) for two weeks.
    
17. Remove bagged tray from refrigeration. Remove substrate tray from bag and place in fruiting chamber or room. Slowly saturate substrate with sterile (65-70°F) water at a rate of 1.5-2.5 fluid ounces/hr/square foot of substrate surface area for 12-16 hours. Allow substrate to drain completely (for about 24 hours).
    
18. Fruiting is when the mushroom comes up from the substrate. Make sure the substrate moisture is around 50% and the relative humidity 85-95% with an air temperature of 73 - 77°F.