Mulching 101 -- Your Questions Answered
Mulching may sound mundane, and doing it is even mundaner. But mulching the garden is one of the most essential ways to ensure its success, especially with the hot summer ahead. Therefore, let Grumpy guide you through all the in's and out's of mulching properly.
What is Mulch? Mulch is material you cover the soil with after planting to do such things as reduce run-off and keep down weeds. Mulch can be organic (pine straw, bark, etc.) or inorganic (white rock, lava rock, recycled rubber, etc.). Grumpy recommends using only organic mulch in a Southern garden, lest it resemble the lovely landscaping at the corner gas station.
What Kind of Organic Mulches Are There? Organic mulch consists of recycled plant parts, so choose mulches made from plants that grow locally. They're cheaper and look appropriate for your state or region. For example, bald and pond cypresses are plentiful in Florida, so many Floridian use cypress mulch. In Alabama, we favor pine straw and ground pine bark made from our native pines. From Virginia north, shredded hardwood mulch is the norm. They all do a good job.
How Does Mulch Benefit the Garden? 1. It keeps down weeds. 2. It cools the soil and conserves soil moisture. 3. It controls run-off from heavy rain and reduces erosion. 4. It puts a "finishing touch" on a garden planting, like the wrapping on a gift. 5. It it adds organic matter to the soil as it decomposes. Nothing does a better job of improving soil than organic matter. The better your soil, the better your plants.
When Is a Good Time to Mulch? Grumpy mulches primarily in spring and fall. In spring, I mulch new plants after planting. In late fall after a hard freeze, I also mulch plants that may not be completely cold-hardy in my area to protect them from a cold winter. Having said this, mulch any time you really need to.
How Much Mulch Should I Put Down? Can you mulch too much? Yes, you can. Grumpy recommends putting down a layer no more than 2 inches deep. Don't put down new mulch until the old mulch has mostly decomposed. Don't pile up mulch around trees like this sad example here.
This is called a "mulch volcano." It's bad for several reasons. Tree roots can grow into the mulch instead of the soil, making the tree less drought-resistant. Bugs and critters can hide in the mulch and bore into the trunk. Mulch volcanoes also reduce the oxygen supply to roots, while aiding harmful soil microbes that produce toxins. Mulch should never touch the trunk of a tree or shrub. There. I said it. So it shall be done.
What Do You Think of Dyed Red Mulch? So glad you asked. I loathe it. You usually see it in gardens that look like this.
But forget aesthetics. There's a good reason why I would never use dyed mulch. It isn't made from natural wood.
Unlike shredded or ground bark, dyed mulch doesn't come directly from trees. Instead, it's made from ground-up wooden pallets and waste wood. Waste wood like someone's pressure-treated deck they tore off and threw away. There are no standards for what's in dyed mulch or where it comes from, especially if you buy it in bulk. It could contain insects, pesticides, preservatives, anything. The only thing about it that we know is safe is the source of the red dye. It's iron oxide. Rust.
Can I Mulch with Wood Chips from a Tree that Was Just Ground Up? Not right away. Fresh woods chips need to age about 6 months before you use them. The reason? Soil microbes that start breaking down fresh chips will rob the soil of nitrogen and stunt your plants. You can also find ugly, slimy fungus growing in fresh chips. Of course, you can make it all better. Just dye the fungus red.