By: Violette Govan
In the health and gardening sector of the world, the current craze has been all about medicinal mushrooms! If you scroll through social media, you’ll find a plethora of images depicting plates piled high with gourmet mushrooms, superfood diets containing the mysteriously gilled fungi, and typically troves of comments wondering how you can tell if a mushroom is safe to eat. With all this hype surrounding the whimsical fruiting-bodies going on, I’ve decided to share what I’ve learned about growing edible mushrooms and teach you the process along the way.
A few years back I had the opportunity to volunteer with UNF Ogier Gardens, and during that time we grew and harvested shiitake mushrooms. Fascinated by the novelty of the experience, I learned that the many kinds of mushrooms require different substrates, nutrients, and conditions to fruit, that you’ll save time studying which mushrooms you should, rather than shouldn’t eat, and that it’s important to trust in the process, as some fungi have a longer incubation period than others. Ultimately, the reward of the experience alone is unmatched, but for those needing a little more convincing, the harvests should more than pay for any upfront costs.
Let me begin by introducing shiitake mushrooms, Lentinula edodes, which are flavorful immune-boosting toadstools found on fallen deciduous broadleaf trees. Although other varieties can grow on a multitude of surfaces like cardboard or coffee grounds, shiitake requires the nutrients from a wood-based substrate like our oak trees to thrive. Alternatively, you could use sawdust blocks to grow shiitake, but for this article I’m going to teach you the log-based method. Ergo, you will need to source fresh logs from an oak tree, preferably trimming these logs the same day you plan to inoculate. The ideal log will be three to six inches in diameter, and three to four feet long without any sign of moss, mold, lichen, or pre-existing fungi.
The first thing you’ll need to do is order your spawn, aka live mycelium culture, or what you’ll use to start growing your own shiitake mushrooms. When selecting a strain, I recommend you focus on finding one that can tolerate a wide range of growing conditions, such as the beginner friendly WR46. The simplest method is to use “plug spawn” which are conveniently inoculated wooden dowels that will be inserted into your logs like planting regular seeds. While waiting for your spawn to arrive, you should prepare a shady, well-ventilated location to place the logs for the duration of the incubation and fruiting period. A straightforward, cost-effective method is to line up a few wooden pallets for keeping your logs raised above the ground and possible competing fungi, then crafting a railing along the longest ends to stack your logs vertically against. You’ll need to finish your structure by securing a shade screen around the exterior that won’t prevent air flow or trap moisture.
You should wait until all chance of frost has subsided and spring arrives to inoculate your logs, usually around late March through April for us. On inoculation day, you will need a block of wax, a drill, a 12mm drill bit (your spawn provider can verify the bit size you’ll need), a butane torch, paintbrush, hammer, protective gear, and a clean workspace. Start by drilling one-inch deep holes down the length of each log about six inches apart, then turn the log a few inches and drill alternating holes until the entire circumference of the log is complete. A three-foot log may need up to fifty plugs, so plan accordingly. Once you’re finished, it’s as simple as hammering your spawn into each hole until the plug is flat with the surface of the log. Finish by melting the wax with your butane torch and spread a layer over each plug with a paintbrush to seal the hole. Set each log upright in your shade structure and prepare to have them incubate for six to twelve months. About once a week, the logs should be watered for ten minutes, but if we get adequate rain one week you can forego watering that week. On the other hand, if it is bone-dry one week, you should increase watering to two times that week. During the incubation stage, the goal is to establish strong mycelium colonies before initiating fruiting, so it’s imperative to maintain proper moisture levels.
Ideally, somewhere between nine and twelve months after inoculating your logs you should initiate fruiting. Shiitake logs under ideal conditions may fruit on their own accord as early as six months, but more than likely you will need to shock them into producing the fleshy, savory caps. To do this, you will need to submerge your logs in clean, non-chlorinated, chilled water for twenty-four hours. You can use a kiddy pool, bathtub, clean pond, ice chest, or bathtub to submerge your logs. After they have soaked for a day, take them back to your shade structure and return them to their vertical stance with ample space between each log for the shiitake to develop. During this stage you’ll need to water your logs twice per day for five minutes to maintain appropriate moisture. It will take approximately two days to two weeks before you will see primordia, immature mushroom pins, begin to sprout. Mycelium tends to send up many mushrooms at once, known as a flush, so be prepared with paper bags to gather what you reap.
Shiitake mushrooms may grow to be large or small, but once the caps begin to open up, you’re ready to harvest! Be sure to collect your mushrooms using a sharp knife where the stem meets the log because pulling or twisting them off by hand can impact future yield. Every five to six weeks after a flush, you can force your shiitake logs to fruit again by repeating the shock bath and keeping up with the watering schedule.
Shiitake mushrooms may have a long incubation period, but the prize is up to six years of mushroom flushes before you’ll need to replace the logs. The experience makes for a unique hobby, a way to teach children to appreciate nature and its bounty, and as a means to connect and provide for your local community. Shiitake is a powerful immune system enhancer, with antitumor and antiviral properties, high levels of calcium, vitamin B2, and vitamin C, and helps to lower blood pressure and cholesterol. You simply cannot find mushrooms fresher in the supermarket! If you have any questions regarding this article or other Florida gardening concerns, please feel free to email me at questions@abc-pestcontrol.com attn Violette, and remember- without plants we wouldn’t be here!