Much Ado about Mulch

Today, I would like to clear up some misconceptions about mulch.

First off, mulch is not a soil amendment. Instead, its primary job is to protect the ground.

There are different types of mulch depending on their uses:

Mulch that is meant to not only protect the soil but also to decompose and add humus is made up of finer materials that have a certain amount of shredded fine tree bark along with some compost. My favorite is called Azalea/Gardenia mix made from earthworm castings and fine tree cuttings with the various biologicals added. While this is for acid loving plants like azaleas and gardenias, it works great here in Malibu because the soil here is so alkaline, and the acid mulch helps to bring the ph down to more acceptable levels to the plants. The ideal ph is 6.5 to 6.8. Malibu soil is 7.4 or higher.

Then there is decorative mulch that is meant to be there not just for sun protection but for looks. This stuff does nothing to add humus to the soil. So it is not a good idea to simply mulch away with this stuff, thinking that it is good for the earth. Just applying wood chips or wood shavings on top of the ground does nothing to help the soil hold water or to assist the plants. It is, therefore, important that you apply rock dust and compost (and then mulch it over with the chips if you want).

If you do not properly take care of the soil, it will harden on you and make watering down deep, difficult, if not impossible.

Also, many folks believe that mulching will bring termites around. This is not true. Termites do not live in live wood, and if the wood is dead and shredded, that process alone will kill them but when it is piled up, it will heat up, and that will finish off any that are left. Also, termites need a source of water and a way to make tunnels connect em together. Wood chips or any mulch will not support termites nor any other type of insects.

Another thing about mulch that many folks believe to be true, but are totally wrong about, is the belief that mulch will burn and is a fire hazard. Mulch is not burnable once it starts to decompose. Wood chips will get wet from the regular watering and will stay moist. On top of that, if there is a fire, all you have to do is to soak the mulch and it will act as an additional fire barrier.

I would place a drip system which would get buried over by the wood chips. This would keep the water below ground and help the soil to retain it longer. It is of particular importance to apply rock dust, compost and mulch around trees as well as the drip system.  I use what I call “ Tree vents” (clay drain pipes available from Bourget Bros in Santa Monica). These pipes are about 1 1/2 foot long and get buried into the ground at ground level with a 2 gallon per hour drip head placed above it. The whole thing gets mulched over. Inside the tree vents is where you apply the organic fertilizers and, or, special liquids that not only fertilize the trees but helps to establish a microbial colony around the tree roots. By providing weekly deep watering, it will encourage the tree roots to be robust and healthy and allows it to withstand drought and stress.

Many folks have been applying a basic mulch from tree bark without apply proper nutrients, nor proper watering, and therefore are now having tree problems since the soil is drying up.

Do you know what you get when you add water to clay and then heat it up? Ceramic. Simple.

This year has already been one of the hottest years for Malibu ever. We moved here in 1984 and have never seen it get to 100 degrees here. This year we will see more days of very high temperatures, and, if you are not careful, you will lose your trees over night! One day the tree looks fine, the next day it is dead.

So mulching is only one important aspect of proper property care. Learn the different types of mulch and the different ways you can use them. Make sure you have changed over to a drip system that you bury under the mulch. Just be aware that the drip system will have to be changed in about 5 to 10 years. The newer systems will last longer than the previous versions of drip systems since the newer drip lines have drip heads built into them, as well as pressure regulators. I would add a fertigation unit into the drip lines so that you can then add various organics to the fertigation unit and it will automatically go out through the drip lines to the property. Ideal for compost tea or an organic slow release fertilizer. Look up fertigation on google to find out more.  Try Ezy-Gro units as they are the best.

So please, before you apply mulch, give the soil a good layer of rock dust (for minerals), compost for nutrients, microbes, and then mulch it over. You should have converted everything over to drip except the lawn (there is a way to bury the drip line in the yard too!). Best to water deeply once or twice a week, then to do shallow watering daily or every other day. Shallow watering causes plants and trees to have roots along the top and not deeper. Shallow roots will get burned by the heat. Also, you need to be careful of overwatering as well as underwatering. Can you tell the difference?

Any questions send me an email at andylopez@invisiblegardener.com

Love

andy Lopez

Invisible Gardener