Why put compost in your orchard? The benefits are many. Adding compost will add organic matter to your soil, and thereby feed your trees and bushes with vital nutrients. Additionally, spreading compost around the base of your trees and bushes will help with water retention and may reduce your irrigation needs. Compost also buffers the soil PH, as well as enhancing the soil structure, porosity and density. Lastly, compost will boost the microbiology of your soil, especially beneficial fungi and bacteria. This increased soil life can actually serve to reduce disease pathogens in your orchard!
Orchard Compost Composition
Composting in your orchard is more than just adding nitrogen to your soil. In fact, orchard compost should be aged and should contain a good amount of lignin, an organic substance that binds cells, fibers, and vessels in vascular plants. Adding rock dust and azomite clay into your compost a few weeks before spreading it will help the transfer of microorganisms and increase the mineral nutrients in your soil, and therefore your trees. You also want a healthy amount of beneficial fungi in your soil, which you can gain by adding humates to your compost. Because this compost specifically designed for orchard use is not high in nitrogen, spreading it in the autumn will not promote growth during the winter.
Materials that can be composted
Compost Timing in Orchards
The best time of year to put compost down in your orchard is in the late autumn. When about half of your trees’ leaves have fallen, you can lightly spread your compost– 1 to 2” deep around the base of your trees starting a few inches out from the trunk–and then mow the rest of the leaves to help them decompose faster and mix them with the compost you have spread. You can mow again when the rest of your leaves have fallen. This process of mowing and composting not only creates more fertile soil, but also helps to break down any fallen leaves and fruit that might carry diseases into the next year (NOTE: spraying compost tea after leaf drop is another effective alternative). If you want even more water retention and added wind protection, you can also add a layer of wood mulch or straw on top of your layer of compost.
Freshly spread compost in an orchard
Tips for Autumn Composting
The autumn is an excellent time to gather materials for making your own compost. A healthy compost pile will have one third “greens” and two thirds “browns.” Greens are materials high in nitrogen, such as your food scraps or your garden weeds. Browns are materials full of carbon, such as brown leaves, wood chips, or straw. These “brown” materials are more plentiful in the autumn, but harder to find naturally in other seasons. Therefore, the autumn is an excellent time to save your brown leaves in burlap sacks to be used throughout the other seasons.
If you have a huge excess of leaves, you can also make a compost pile of only leaves. Put a layer of leaves, followed by a layer of soil, and continue this process until you have a pile at least 3 feet high and 4 feet in diameter. With only a couple turns of the pile, this leaf compost should be ready to spread in your orchard or garden by the next fall!
Composted leaves (aka leaf mould) are gold!
Here’s a great article to get you started on working with the abundance of leaves in your forest garden or community orchard space: http://www.epicgardening.com/composting-leaves/
This edition of POP Tips compiled by 2015 Education Intern, Rachel Baltuch, and Program Director, Robyn Mello.
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