Years ago, it was routine practice to add fertilizer and compost to the hole before planting a tree or shrub. That practice has been pretty much proven to be wrong. The current standards suggest no amendments and fill the hole with un-amended soil that came out of the hole. We are making an exception to the current practice because the professionals have yet to catch up to technology. You can add products containing beneficial microbes which reduce the stress of the planting process and contribute greatly to the ongoing health of the tree or shrub. You still don't add fertilizer, but a little compost and soil microbes are a value.
Adding Beneficial Root Fungi to the Hole
What Are Mycorrhizae?
Certain kinds of fungi associated with the roots of plants have occurred naturally in the soil for 400 million years. Under the right conditions, they form a close symbiotic relationship with plant roots. They are called mycorrhizae (from the Greek "mukés", meaning fungus, and "rhiza," meaning roots).
This little known family of beneficial fungi live in and around the roots of 95% of the earth's plant species that have not been disturbed by humans, serving as a secondary root system by extending themselves far out into the soil. Mycorrhizae extract mineral elements and water from soil for their host plant, and live off the plant's sugars.
Trees, shrubs, flowers, and other landscape plants with a good population of "mycorrhizal roots" systems are better able to survive and thrive in stressful man made environments.
When mycorrhizal fungi colonize the plant's root system, they create a network that increases the plant's capacity to absorb more water and nutrients such as phosphorus, copper and zinc. This process in turn enhances growth and favors rapid development of roots and plants.
Most Soils Bereft of Mycorrhizae
However, in most soils that have been disturbed by residential construction, or intensive cropping practices with applications of fertilizers containing pesticides and other chemical products, the mycorrhizae content has considerably diminished, and has become insufficient to significantly enhance plant growth.
Mycorrhizae Now Available For The Plants of Yardeners
In the past decade, companies have developed the technology needed to reproduce natural mycorrhizae and package them in a medium that keeps them viable for several years. These new mycorrhizal products are used when planting new plants, transplanting plants to a new place, or on plants already in place. The idea is to get the mycorrhizae down into the root zone of a plant so they can attach themselves to the root system and start doing their good works.
Different groups of plants use different kinds of mycorrhizae, sort of keeping things in each family. Therefore you want to be sure to read the label on any of these products to be sure the material contains mycorrhizae appropriate for the plants you want to improve.
How Do I Use Mycorrhizae??
In the past, the products containing Mycorrhizae were most often applied as part of the planting process. The Mycorrhizae are sprinkled into the hole before the plant is placed in the hole. Some products can be applied around existing plants. Now there are products that can be sprayed with a hose end sprayer which is very easy to use. For details see the instruction with the product descriptions in Tool Shed linked below.
For information about mycorrhizal products and a retail source go to Mycorrhizae For Landscape Plants
Adding Soil Microbes