Mulch on, Mullch off, Transplanted and Still Blooming, Cinthia Millner

Mulch On, Mulch Off?

Oh for pete’s sake, mulch off.

Okay, so mulch is good for moisture retention and weed control, for sure. It is also bio-degrades, and as it degrades it helps improve soil content, which in turn helps with gas exchange, drainage, root growth and so forth. So yes, please mulch, compost, fertilize, pile your shredded (or not) leaves on in the fall, and generally improve your soil. That really is your purpose in the garden: Leave the soil in better condition than when you arrived. And, just FYI: Landscape fabric does not help that cause (improving the soil), so get rid of that stuff.

But, as always, too much of a good thing is too much. Case in point.

Mulch on, Mulch off, Transplanted and Still Blooming, Cinthia Milner

Suburban trees all in row, their roots suffocating under so much mulch.

What’s with the candle in the cupcake look?

We’ve taken the concept of mulch and because it is a good thing, we do what we do best (or maybe what I do best), overdo a good thing. If a little is good, a lot must be great.  We live in an extreme world. The middle road has been forsaken. From fundamentalists to liberals, there’s an extreme. It is showing up in the mulch in our yards. Okay, bit of an exaggeration there, but I just did a quick glance at FaceBook, which is the new political/religious opinion forum, and I got carried away.

Back to the mulch. Mulch off, please.

Remember when you were a kid tromping through the woods and playing in the root flair of those tall forested trees? Trees with no mulch? Yep, that’s what we need to see around a tree, the root flair. Doesn’t mean you can’t mulch, just means you’ll save some money, and not need the mulch truck to drive up every year and dump yet another load, even though the last three loads are still perfectly fine.

Here’s a good rule of thumb for mulching your trees and shrubs, provided by the Bartlett Tree Research Team. (Yes, the Bartlett pear, you need not like the tree to appreciate their research.)

I have a client whose mulch is 10″ thick (I measured it). Her gardener was planting in the mulch, not the actual soil. Understandable with 10″ of mulch. Every spring and fall, the yard guys drive up and dump another load of mulch. She likes the dark color. I said, “Me too, turn it over each fall and it will be dark.” Or have them turn it over if you don’t feel like it. (And really, who feels like it?)  She had called me over because all her plants were dying. “What is wrong?” Plants don’t grow in mulch. Plants grow in soil.

Another client, and I watch as the yard guys drive up, rake 6″ of mulch off, put it in their truck, dump 6″ of new on, and then drive off with last year’s mulch. I suspected they were going to dump the 6″ they collected on someone else’s trees. My client was happy. Her yard looked “clean and groomed.” I love the way fresh mulch looks, too. For that first week after mulching, I’ll admit to loving the cleaned-up look of my yard, like a deep clean of my house. I feel as though the world is in order.

But clean and groomed isn’t the sole purpose of mulch, and adding more when more isn’t needed for grooming sake’s ends up potentially harming the plants.

You should always see 25% of the root ball when planting a tree or shrub. If all you see is mulch there’s a good chance bugs and disease will harbor in that mulched volcano base, or worse, the roots of the tree will grow up into the mulch (believing it is planted deeper) and girdle the tree, potentially killing it.

Bottom line: Mulch on for about 2-4″. More than that? Mulch off.