Mushroom cultivation is a delicate process where many things can go wrong. Because of this, it’s useful to have a guide to help you troubleshoot any issues you may encounter. One problem you may have is overlay in your casing layer. So, what is overlay, and how can you avoid it? We’ll tell you more below. But before we begin, let’s define what overlay is and why it isn’t good for your casing.
A Few Definitions
We must first define some terms to understand what overlay is and how to avoid it. To begin, the most important aspect of the mushroom—and the biggest—is the mycelium. The mycelium is the body of the mushroom that you typically find underground. When we think of mushrooms, most people imagine the fruiting body of the mushrooms. These are the stem and gills that stick up from the ground.
The mycelium is far larger, and when you cultivate it at home, it grows through a substrate layer. The substrate layer is the medium that the mushroom grows through. Finally, the casing layer is the layer of moist material—inorganic, organic, or both—that you put on top of the colonized substrate before it begins to fruit. This mushroom casing mix is necessary for your mushrooms to grow healthy.
What Is Overlay?
So, what exactly is overlay? Most modern professional mycologists explain that casing overlay occurs when the mycelial growth over the casing surface doesn’t show any inclination toward growing pinheads. In other words, your mushrooms simply aren’t growing. This happens when mycelial growth sits in the casing layer too long. You can also cause this by over-misting your casing layer or not keeping it moist.
Furthermore, if the monotub isn’t humid enough, it can cause overlay. That said, avoiding overlay in your casing layer is relatively easy. Check out how below.
How To Avoid Overlay
The first thing you need to do is refrain from over- or under-moisturizing your casing layer. Make sure you gently water your casing layer on a schedule. This is a delicate process. If your casing layer is too moist, wait before you mist it again. If it’s too dry, mist it. Overall, you must pay particular attention to your casing layer’s appearance. You should also change environmental conditions before the casing becomes over-colonized, at about 70 to 90 percent of the casing layer. As long as you follow these tips, you should be able to grow your mushrooms with ease.