Mushrooms are growing in the garden because there is likely a combination of moist soil, high organic matter (such as decomposing leaves, dead roots, or wood), and sometimes shady conditions that create an ideal environment for fungi to thrive. Mushrooms are the fruiting bodies of fungi that help break down organic material in the soil, indicating healthy and fertile soil. However, their presence can also suggest that the soil is too wet or not draining well. Mushrooms themselves are not harmful to the garden and actually play an important role in nutrient recycling, but if mushrooms are a concern (for pets or kids), they can be removed manually. Mushrooms tend to appear after rain or watering and often disappear when the soil dries or conditions change.