If you have ever marveled at the healthy foliage of your plants, you may want to credit more than just pure genetics and good care. Mycorrhizae are a group of beneficial fungi that work together with plant roots, creating a harmonious symbiosis that significantly boosts plant growth, disease resistance, and stress tolerance. Mycorrhizae are present in most soils, but their numbers can be low due to human activities such as tilling, overfertilization, and exposure to harsh chemicals. In this article, we will explore the benefits and types of mycorrhizae in the garden.
What are Mycorrhizae and How Do They Work?
Mycorrhizae are a type of fungi that form mutualistic associations with plant roots. They penetrate the root surface and extend their hyphae (fine, threadlike strands) into the surrounding soil, greatly expanding the root system’s ability to absorb nutrients, water, and minerals. In exchange, the fungus receives assimilable carbon compounds from the plant, allowing it to thrive. This synergistic relationship is vital for many plant species, as mycorrhizae provide an extended network of nutrient transmission that can fetch minerals and nutrients from further afield than plant roots can themselves. The fungi’s surface area and containment (length, fineness, and complexity) greatly augment the absorptive network of the plant roots and can increase surface area for nutrient transfer by up to 1000 times!
The Two Major Types of Mycorrhizae
There are two main types of mycorrhizae: endomycorrhizae and ectomycorrhizae.
Endomycorrhizae, also known as arbuscular mycorrhizae, are the most common and important type of mycorrhizae in agricultural soils. They form close associations with about 80% of plant species, including most crops. Their hyphae penetrate the root cells and form a distinctive structure called an arbuscule, which promotes nutrient exchange. These mycorrhizae are especially useful in environments where nutrients are less pronounced.
Ectomycorrhizae are mutualistic fungi that form dense network hyphal associations in association with the outer layer of roots. These mycorrhizae form sheaths called Mantles that envelop the roots’ entire surface and extend hyphae outwards between mycorrhizal pairs to interact with other root systems and organic matter in the soil.
The Benefits of Mycorrhizae in the Garden
Mycorrhizae’s benefits in the garden are many. Here are some of the most prominent ones:
– Improved nutrient uptake: Mycorrhizae trade essential minerals and nutrients like phosphorus, nitrogen, potassium (NPK), and copper with roots, creating a robust flow of nutrients that help plants grow lush, green leaves and strong, healthy roots.
– Enhanced resistance against stress: Mycorrhizae can help plants combat stress from drought, high temperatures, salinity, phyto-toxicities like chemical and heavy metal contamination that acts to reduce plant yield.
– Increased disease resistance: Studies show that mycorrhizae can boost the plant’s resistance to pests and soil-borne pathogens such as fusarium, verticillium, and pythium. They form a physical barrier that prevents harmful organisms’ spread, sending defensive signals, and creating biological competition.
– Reduced water requirements: Mycorrhizae allow plants to take less water to achieve their full growth and potential. They help create a reserve of stored water in the layers of soil that would be sufficient for a season of growth.
How to Boost Mycorrhizae in Your Garden
If you want to get the most out of mycorrhizae in your garden, consider these tips:
– Avoid tilling: Tilling can break down the soil structure, reducing mycorrhizae populations.
– Use compost instead of synthetic fertilizers: Compost helps improve soil health, increases organic matter that feeds mycorrhizae, and brings trace elements and microbial soil fauna that can help break down difficult elements.
– Use less water: Mycorrhizae help plants take less water, but they work best in slightly moist soils.
– Promote biodiversity: Many plant species encourage mycorrhizae growth. Choose plants that are known to stimulate fungal growth or plant a polyculture that includes diverse species.
FAQs about Mycorrhizae in the Garden
Q: What are some plants that depend on mycorrhizae?
A: Most plants native to grasslands, woodlands, and deserts, such as shrubs, wildflowers, and trees, have mycorrhizae associations. Examples include beans, corn, potatoes, and tomatoes. When grown in healthy soils, their growth and productivity soar.
Q: Can I add mycorrhizae to my garden?
A: Yes, you can! You can purchase mycorrhizae products and mix them into the soil. Be sure to follow the manufacturer’s instructions and keep the soil damp until the product is fully colonized.
Q: Are mycorrhizae fungi harmful to humans and pets?
A: Mycorrhizae fungi are beneficial to plants, humans, and pets. They are non-toxic and non-pathogenic, meaning they do not cause disease in humans or animals.
Mycorrhizae are a vital component of healthy and productive gardens. They boost nutrient uptake, resistance against stress and disease, and water efficiency. Knowing how these fungi work, their benefits, and how to stimulate their growth ensures a healthy and greener garden, often with tremendously reduced costs and impacts on the environment. Happy gardening!