Mushrooms growing in your greenhouse on the ground, on mulch or in potted plants might get you wondering if you are doing something wrong. Although mushrooms can look disturbing especially in potted plants, are they really bad for soil?
To understand why are mushrooms growing in a greenhouse, we need to know what they are, how they grow and what they do. So, mushrooms growing in soil are fungi. The mushroom caps that you can see in potted plants, growing on a lawn or garden soil are fruits of fungi.
Now, there are ‘good’ and ‘bad’ fungi. We all heard of the most popular kind of ‘bad’ fungi which is mold. If you came across white powdery mold or brown downy mold in your greenhouse, you need to get rid of it immediately.
Apart from the types of fungus that are parasites, mushrooms growing in garden soil or greenhouse are harmless to your plants. Moreover, they can actually improve the quality of your soil. Mushrooms help plants exchange nutrients or top up the amount of nutrients in soil.
Let’s look at their structure first. The main structure of fungi are mycelium and hyphae that form a network under the ground. The mushrooms that you can see are actually fruiting bodies of fungi. These fruiting bodies release spores.
Spores are spread by wind or by insects and animals. Sometimes, you can introduce spores inside a greenhouse by brushing spores off clothing. If mushrooms are growing with potted plants, it means that soilless mix was contaminated with fungus spores.
For fungi to reproduce their spores need to attach to a nutritious source. Most of the time, it is decaying organic matter, decaying wood and leaves. Fungi don’t have chlorophyll like plants do, so they can’t make their own food.
So, why are mushrooms growing in a greenhouse?
Mushrooms growing in a greenhouse indicate that your soil is healthy and contains lots of organic matter. Fungi are actually beneficial for a greenhouse. They decompose organic matter in soil like dead leaves and wood chips into nutrients that plants can use.
Fungi hyphae network and plant roots form a symbiotic relationship. Fungi provide nutrients that plants need to produce the sugars. Also, fungi increase surface area on plant roots. In return, fungi can feed on sugars that plants produce.
As a result, it is easier for plants to access water and nutrients from the soil. Furthermore, plants ability to tolerate droughts and resist diseases increases. They can withstand weather conditions better and don’t suffer from transplant shock.
Overall, plants growth rate increases at every stage of development. Mushrooms growing in a greenhouse also improve the soil. Here are the benefits:
- Improved soil structure
- Increased drainage
- Suppressed soil-born diseases
Also, some types of fungi are saprophytes. They break down and recycle dead plant and animal material. So, a mushroom or a group of mushrooms decompose either dying parts of your lawn, dying plant roots under the soil or dead plants or animals. As a result, mushrooms release nutrients back into the soil.
Why are mushrooms growing in potted plants?
Most of the time mushrooms are growing in potted plants because the potting mix was contaminated with fungi spores. To grow they need moist, cool and humid environment. Spores need to attach themselves to the roots of the plants or decaying organic matter in the soil to feed themselves.
It is enough for spores to attach to a wood chip to start to grow. Most of the times mushrooms will appear in potted plants in summer when environment is right for them. For mushrooms to sprout temperatures around 50-60°F are enough.
Although mushrooms are harmless to plants, sometimes it is better to get rid of them. Some mushrooms can be pesticides if pests feed on them. However, they can also be poisonous for humans and pets. That is when they can cause serious harm to anyone who had a bite.
Why are mushrooms growing in my raised beds?
If mushrooms are growing in your raised beds it means that they are high in organic matter or that you are overwatering. Spores could get into the bed with a contaminated commercial potting soil. Also, spores can get in your raised beds through airborne movement or from your clothing.
Overwatering is also a very common reason why mushrooms are growing in raised beds. They can only survive in moist and humid conditions. In comparison to plant cells that increase number of cells to grow bigger, fungus has the same number of cells and expands its cells with water to increase in size.
So, mushrooms will grow faster if you provide more water. To completely get rid of mushrooms or to stunt their growth, you need to control watering. Mushrooms growing on raised beds are not going to harm your plants. Instead, they will break down organic matter enriching the soil.
Conclusion
To sum up, mushrooms can look disturbing on the soil or raised beds in a greenhouse or especially in potted plants. It can make you think that you are doing something wrong. However, it is just an indication that your soil is rich in organic matter.
Most of the time spores are introduced with the contaminated potting mix and you can provoke mushroom growth by creating humid conditions. Which means overwatering your plants. It is important to remember that mushrooms are not harmful for your plants, but don’t eat them!
Do you keep mushrooms growing in a greenhouse or getting rid of them straight away? Share your thoughts in the comments section below!
Happy Greenhousing!
