Dealing with Unexpected Guests: Mushrooms in Your Herb Garden

About two weeks ago I went to tend to my herb garden only to be startled to find mushrooms had grown out of nowhere. At first I was a bit concerned and thought that I had to throw out all my herbs and start over. After a trip to my local plant nursery I quickly found out that they are not harmful to the herbs, or any other plants that they might pop up next to. In fact, mushrooms appearing in gardens is actually a healthy sign that the soil contains organic matter. After all soil is a living component of a garden. Thankfully I did not have to throw out all my herb vegetables and start over but I still needed to figure out why was happening and how to prevent it from occurring.

In my research I discovered two reasons why mushrooms can occur and my herb garden happened to fall into both of these scenarios. First is organic matter and moisture. Mushrooms thrive in environments rich in organic matter, such as decomposing plant material or tree roots. The soil I used in my herb garden was a combination of raised bed potting mix and compost, which contains lots of organic matter and that is what you want in your garden for plants to thrive. However, if the soil stays consistently moist, it becomes an ideal breeding ground for mushrooms. Initially I was showering my herbs every other day or so, not really having a routine watering schedule. Then I had drip irrigation installed so that I wouldn’t forget to water the garden that’s when the herbs started to get over watered and that’s when I noticed one morning that mushrooms had appeared. I am still in a trial and error phase for figuring out how much and how often to water my herbs. The second scenario is lack of air circulation, which can also contribute to the growth of mushrooms. My herb garden is planted in a shallow raised bed and is completely planted out so there is not much air flow happening between the plants. Also, the herb garden has been shaded since the beginning of May when there were a couple hot days of gardening so I decided to setup a popup canopy. Knowing that plants need the sun to grow and also need to dry out a little bit in between the next watering that probably wasn’t the best decision. Even a few weeks of shading my herbs goes to show that the garden is retaining too much water and not getting enough air flow to stop the mushrooms from growing.

Once you have mushrooms it’s hard to stop them because they have spores and can easily get into the soil. Natural ways to prevent mushrooms from popping up in the garden deal with preventing an environment where mushrooms thrive. These methods are as simple as adjusting the watering schedule, in this case it would be watering less. Improving the drainage by amending the soil so that it doesn’t stay too wet in between waterings. Providing adequate sunlight and having proper plant spacing to encourage air flow will also prevent the soil from staying too moist.