A fascinating relationship has developed between roots of many plants and a fungi called mycorrhizae. Mycorrhizae are symbiotic fungi that live in close association with many plants. Mycorrhizae can be applied to roots in order to help plants to draw up nutrients, water and minerals. Plant roots provide carbohydrates for mycorrihizae that grow on them. Mycorrhizae fungi increase the ability of roots to draw up nutrients from the soil. Mycorrhizae are much smaller in diameter than roots and this enables them to provide a larger surface area for absorption. In addition mycorrhizae release enzymes into the soil that dissolve nutrients enabling plants to take them up. It is a good idea to add mycorrhizae to soil when planting trees or shrubs as it increases the ability of the roots to draw up nutrients thereby helping plants to settle in their new locations. Mycorrhizae release enzymes into the soil that dissolve nutrients enabling plants to take them up. You can buy mycorrhizae from garden centres in powder form.