Mulch matters more in Texas than almost anywhere else in the country. Bare soil in San Antonio in July hits surface temperatures over 140°F by mid-afternoon. Roots cook, soil microbes die, water evaporates before it reaches anything that can use it, and weeds — which are better adapted to disturbance than your plants are — colonize fast. A thoughtful three-inch mulch layer drops surface temperature by 30 to 40 degrees, cuts irrigation needs roughly in half, suppresses 80 to 90 percent of annual weeds, and feeds the soil as it breaks down. There is no other single intervention that pays back this much.
But mulch is not one thing. The mulch aisle at the box store is a confused pile of products that behave differently in the ground. Some feed the soil. Some sterilize it. Some hold moisture. Some shed water like a roof. Picking the right one matters.
What we use: native hardwood.
Our default mulch for planting beds is native hardwood — usually a mix of oak, elm, hackberry, and pecan ground from regional clearings. It's coarser than the dyed shredded stuff at the box store, decomposes at a moderate rate (full breakdown in two to three years), holds moisture well, and feeds the soil food web as it goes. The texture interlocks enough that it doesn't blow around in a Hill Country thunderstorm or wash off a slope.
We source it from regional mulch yards that grind clearings from real Texas tree work, not from out-of-state landscape lumber operations. Local sourcing matters because the mulch comes pre-inoculated with the fungi and bacteria already adapted to central Texas soil. We lay it three to four inches deep over a freshly prepped bed, pulled back two to three inches from every stem and trunk.
The cedar mulch argument.
Howard Garrett has been arguing against cedar mulch in planting beds for thirty years, and on this one we mostly agree with him — with a clarification. Fresh cedar mulch (the orange-red shreddy stuff sold as "cedar mulch" or "red cedar mulch" — really our native Ashe juniper) releases allelopathic compounds, primarily terpenes and thujone, that suppress seed germination and slow the root growth of nearby plants. This is the chemistry Ashe juniper uses to outcompete other species in the wild — and it's the same chemistry that ends up under your roses.
Cedar also resists decomposition. Cedarwood lasts decades in the ground because the same volatile oils that make it allelopathic also make it fungistatic and insect-repellent. That's great for a fence post. It's not great for a mulch you want to feed soil. A cedar-mulched bed three years in has the same volume of mulch and the same impoverished soil underneath it that it had on day one.
Where cedar mulch is fine: paths, dog runs, around the foundation as a termite-and-roach deterrent, decorative areas you've explicitly decided won't be planted. It smells good, lasts forever, and looks tidy. Just keep it out of the beds where you actually want things to grow.
Leaf mulch from on-site trees.
If the property has mature oaks, elms, or pecans, the cheapest and best mulch available is already falling out of the canopy every November. Whole leaves blow around and pack into mats. Shredded leaves — run through a mower or a leaf shredder once — make the single most nutritionally complete mulch you can put on a bed.
Shredded leaf mulch breaks down inside a single season, which sounds like a downside until you understand that what it's breaking down into is essentially the same humus you'd get from a year of compost. We use it as a thin top layer over hardwood mulch on properties with enough canopy to supply it, or as the sole mulch on beds we plan to refresh annually anyway. Leaf mulch and well-finished compost are nearly interchangeable nine months in.
The one rule: shred the leaves before laying them. Whole leaves form a waxy mat that sheds water and smothers ground-level perennials. Shredded leaves behave like a proper mulch.
Straw, rock, and decomposed granite.
Straw. Wheat straw or native prairie hay works on annual vegetable beds and on freshly seeded native grass installations where you need temporary cover while seed germinates. It breaks down fast — a single season — and is mostly a stopgap. Don't use straw with seed heads still in it unless you want a wheat lawn next spring. We use it for short-term jobs and don't put it on permanent ornamental beds.
Rock mulch. Limestone gravel, river rock, lava rock. We use limestone gravel and river rock on dry creek beds, drainage channels, and around foundation perimeters where we want a permanent inorganic edge. We do not use rock mulch in planting beds where we want the plants to be healthy across decades. Rock reflects heat upward, raises soil and root-zone temperatures, and gives the soil nothing as it ages — and rock mulch beds get harder to maintain over time, not easier, as weed seeds blow in and germinate in the dust that collects between stones.
Decomposed granite. DG is our default for paths, patios, fire-pit aprons, and any walking surface that needs to drain and breathe. We do not use it as a mulch on planted beds — the fine grit packs into a low-permeability crust that sheds water. As a path material it's nearly perfect for the climate: drains fast, stays cool relative to flagstone, and grades easily.
The Noon mulch stack.
On most projects we end up with three mulches on the property at once, each doing a different job:
Native hardwood mulch on every planting bed, three to four inches deep, refreshed annually with another inch as the bottom layer breaks down into the soil.
Shredded leaf mulch from the property's own canopy, top-dressed onto beds in late fall — free, nutritious, and recycles the nutrient cycle the trees built.
Decomposed granite on paths and patios, edged with steel or limestone to keep it where it belongs.
This stack means about 70 percent of the property's mulch comes from the property or from inside a thirty-mile radius. It feeds soil instead of sterilizing it, costs less over a decade than the dyed-mulch refresh cycle most landscapes get stuck on, and holds up. Compost closes the loop — most of the leaf mulch and old hardwood mulch eventually ends up in the pile, then back on the beds.
What holds up.
A mulched bed in central Texas is doing more work than most homeowners realize: cutting heat, holding water, feeding microbes, blocking weeds, and slowly rebuilding the soil profile that caliche and a hundred years of agriculture stripped down. Pick the wrong mulch and you're paying for a decorative layer that does none of those things. Pick the right one and the soil under it three years from now is measurably better than the soil it sat on day one.
That's the test we use. If the mulch is making the dirt better, it's doing its job. If it's just sitting there looking red, throw it on the path and start over.
An old idea.
Covering the ground is not a modern innovation. The Coahuiltecan and later mission-era cultivators of South Texas mulched garden beds with leaf litter, river-cane scraps, and ash from the cooking fire — the same logic, the same outcome. A bare bed in a hot climate has always been understood as an unfinished bed. The dyed-bark aisle at the box store is the novelty. Three inches of native hardwood and the leaves under your own oaks is the older, better answer.