Gardening in El Lago

Trowels & Tribulations in a Suburban Garden - April Issue

By: Donna J. Ward, Certified Texas Master Gardener (Note: This is a reprint of Donna’s article that appears in the La Ventana del Lago.

By now we’ve pretty much got the south forty under control, and we’re harvesting those veggies planted this spring. Perhaps it’s time to give some thought to promoting the general well-being of our landscape trees and shrubbery. Other than the obvious – providing the proper amount of moisture required by each specimen we also need to moderate the soil temperature. This is not only beneficial in the chilly winter months, but also in the sizzling temperatures we experience here on the Texas Gulf Coast. There’s a one word answer – mulch!

It’s necessary to keep our trees healthy, not only because we love them and enjoy their shade, but they provide a sturdy grounded feeling to our landscape. Did I mention what they do for our property values?

There’s a right way and a wrong way to mulch. Doing it the wrong way can be fatal to that gorgeous oak shading our homes from the western summer sun. In our neighborhood we’ve all seen ‘volcanos’ piled up against the trunk of a tree. Piled high, it encourages the roots to grow into the mulch eventually strangling the tree. Unfortunately this method is also practiced by some so-called landscape professionals. It doesn’t take a rocket scientist (we have plenty of those living in our neighborhood) to know that when tree bark is kept consistently damp, wood rots! But if mulching is done properly our trees will be strong and healthy because the conditions are right. Doing it right also includes the proper depth. A 2-inch layer doesn’t sound like much, but it’s plenty to start, 4 inches is better, and at 4 inches, we have good moisture retention, weed prevention and soil temperature moderation. Don’t pile too high though, as this will suffocate the plant’s roots. Mulch should go all the way around the trunk but keep in mind that it should never touch the trunk. Spread it from where the trunk’s flare begins at the soil level and out to the drip line if you can, I know that’s a lot of you have a live oak in your front yard! It’s a judgment call; leave it up to you to make that decision. A newly planted tree doesn’t have its roots spread too far, so a circle just a few feet in diameter is sufficient. Roots need to breathe so we can’t pile the mulch more than a few inches deep, and at the risk of repeating myself it should never touch the trunk of our trees or shrubbery. .Anytime is a good time to mulch, but in summer our trees are completely out of dormancy and ready and able to reap the benefits of mulching. Newly planted trees are going to have a hard time dealing with our Texas heat and drought, so let’s make their life a bit easier.

First let’s decide which type mulch to use. Organic is best because it eventually breaks down and increases the nutrients required by each plant. Install a mulching blade on your mower to shred those fallen leaves, and if you pay a lawn service to do the job, insist that they use a mulching blade. The loblolly pine in my back yard sheds enough acid producing needles to do the mulching job organically – and cheaply I might add. Forgot those wood chips unless they have been composted. As raw wood decomposes it ties up much needed nitrogen in the soil making it unavailable to our plants. Some folks recommend straw or hay to do the job, but it deteriorates quickly and we’ll have to practically start over. Of course we can do it the lazy way and buy it by the bag or truck load. We need to be very particular about the ingredients in the mulch we choose. Good composted mulch is deep brown in color. Black mulch is dyed, it does not occur naturally. We may think black mulch is attractive, but industrial wastes, smelter wastes and boiler ash is used to produce that black color that many find appealing. Many of the waste chemicals used to make mulches dark (black) are carcinogenic. The black dyed mulch is bad enough, but seeing the red dyed mulch around our landscape specimens makes me nauseous. As our pets roll around in these dyed messes it’s been documented that cancer in pets has increased dramatically. Of course we don’t want our children, grandchildren or neighborhood kids coming in contact with this poison. Did I forget to mention that dye leaching into the soil isn’t doing our plants any favors? Let’s grab our shovels and rakes; we’ve got plenty of work ahead of us.

P.S. I wrote this column the other day before I came upon a sight that infuriated me. A landscaper’s crew member was down on his knees carefully piling mulch up and around the trunk of an oak in a homeowner’s front yard. He was perpetuating the horrendous practice called “volcano” mulching. That poor tree’s roots will grow up into the mulch – why not – it’s dark and moist – a wonderful environment for tree roots. Roots will begin to grow circuitously in the mulch around the trunk. Of course the girth of the tree keeps expanding as the bark grows. Who’s going to win this battle? – Not the tree or its owner. This poor tree will eventually commit suicide by strangling itself. And to think we pay these “professional” landscapers to help them do it!

Did you know that Trowels & Tribulations is published on the city site on the first of the month? Under Our Community you will find Trowels & Tribulations listed.

Tree trunk with soil