What's the point of Mulch?

        Why mulch? What is it and what does it do for you? Mulch can be almost anything that covers the ground.  Most people think of bark mulches first, but most mulch is no longer bark mulch. Once upon a time the bark from trees was an abundant resource left over from trees run through a sawmill, and some enterprising soul thought to start selling it to people for their garden. Most mulches now contain some bark, but mainly consist of shredded up wood. Other kinds of Mulch include Buckwheat Hulls (pretty, they don’t break down very quickly, and may fly away in a strong wind), Cocoa Hulls (expensive, don’t break down quickly, but do smell like chocolate when new), and even gravel or shredded up old tires.

It is very important that when you spread mulch you do not mound it up against the plant, or cover parts of the plant with it, or rot will occur. Always leave a little room around the stem or crown of the plant.

The usefulness of mulch is two-fold or greater. It covers up the ground and reduces the rate of evaporation of water from the soil. It also breaks up the flow of water across the ground, and encourages more of it to settle into the soil after a rain. Mulch also breaks down. 

Good mulch is a long term soil conditioner that slowly turns into an available food for the plants, and encourages earthworms.  Mulch will also reduce the ability of weed seeds to germinate, and encourage beneficial microorganisms.

Earthworms are one of the best things that you can do for your garden. Their holes aerate the soil and encourage water penetration deep down. The food they eat, they release back into the environment from the other end, and that becomes one of the best sources of nutrients for your plants. Earthworm castings, as they are known, are even sold as high end organic fertilizers for potted plants and vegetable gardens. You may even have seen them yourself, little tiny pebbles of dark dirt that surround their holes after a rain or a heavy watering. They actually plug up their holes in the rain, then open them up again afterwards. A perfectly clean soil, with no mulch or litter covering it, will not have Earthworms for this very reason.

Dyed mulch is actually a negative for the garden. That bright red color, also sometimes a dark brown or black, is almost always a petroleum dye. It is dangerous to use in a garden where you eat the plants, and harmful to your plants, and the Earthworms or beneficial insects, as if you were to spray everything in your garden with kerosene or another lingering form of petroleum. Undyed mulches may not look as rich in color for as long, but they are much more useful. They break down more quickly into available nutrients and are not harmful. Occasionally you may find an undyed mulch that smells like cider, very pungent. This is a ‘hot’ mulch, it has been chipped up very recently, and is very low in Ph (acid) and will burn your plants if applied. A good mulch will have been aged past this point.

The plant world has evolved the way it is over a very long period of time. It is far easier to work with it than against it.  In a natural environment a thick mulch of leaves covers everything, or is worked into the upper layers of soil. Leaves themselves have a nutrient value: Hardwood tree leaves can have a nutrient value of up to 3.5-1-1 .  When you rake up and throw away those leaves in the fall, you are throwing away nutrients. Consider composting the leaves on your property to save yourself some money, or if you can, leave the leaves in place and simply mulch over the top of them. Your yard will look beautiful and will grow even more beautifully.

 For more reading on mulches: http://www.ladybug.uconn.edu/factsheets/tp_05_mulchbasics.html

 For more information on soils and their composition:    http://www.uvm.edu/vtvegandberry/factsheets/soilorganicmatter.html