Shredded Mulch for Florida Beds and Tree Rings

Bare sand between the shrubs is what puts most shredded mulch on a truck here. Peninsula sand drains so fast that a bed watered in the morning can be dry at the surface by early afternoon, and an exposed bed in a long growing season is also an open invitation to weed seed. A cover changes both of those. This one is shredded hardwood in consistent medium shreds, natural brown, laid at a 2 to 4 inch depth.

Bed sand that is dry again by noon

The cover does three separate things on this ground, and they matter in different months.

Through the warm part of the year it slows evaporation from the surface, so water you put on a bed in the morning is still available to roots later in the day rather than gone from the top inch. It also shades the soil, which moderates the temperature swing around the root zone.

Through the wet season it takes the impact of rain that would otherwise hit bare sand and move it. And all year it blocks light at the soil surface, which is the mechanism behind weed suppression: seeds that never see light mostly do not germinate.

What three inches of hardwood shred does between afternoon storms

The shredded texture is the part worth understanding, because it is what separates this from a loose chip or a nugget product. Shreds knit together. They interlock into a mat that stays put when a downpour runs across it, where loose pieces float and end up on the drive.

That mat also breaks down, and in Florida it breaks down faster than people expect. Heat, humidity and a long season mean the layer thins over a year and the color softens from the fresh brown to something grayer. Both are normal. The material is becoming organic matter in a soil that has very little, which on deep sand is an advantage rather than a loss, and it is the reason beds get topped up rather than left alone.

On a bed that sits wet through part of the year, keep the layer toward the lower end of the range. Three inches of mulch over ground that already holds water in the rainy season keeps that surface damp longer than some plants want.

Spreading shredded mulch on a cleared bed, and keeping it off trunks

Clear the bed first, right down to the soil, and pull the weeds that are already there rather than burying them.

Set the depth deliberately. Two inches is a light cover that will need attention sooner; three is the working figure for most beds; four suits a bed with nothing established in it yet and is more than you want among shallow-rooted plants.

Keep it off the stems. A ring of mulch piled against a trunk holds moisture against bark that is not meant to stay wet, so pull the layer back a few inches from trunks and crowns and let the ring sit flat rather than mounded. A flat ring also stays where you put it in a storm, while a cone sheds material downhill.

Edge the bed. A spade-cut trench edge, a timber, a paver soldier course or a steel edge will all hold shreds in during heavy rain. Without one, the first serious storm redistributes a share of the bed onto the lawn.

River rock or pea gravel instead? What each one gives up

Two stone covers get weighed against this on Florida lots, and each trades something away.

River Rock never breaks down, so it does not need topping up and it holds through a hurricane-season downpour better than any organic cover. What it gives up is the soil itself: it adds nothing back, it holds heat around plants on a hot afternoon, and any organic matter that blows into it composts on top and grows weeds where you cannot pull them out easily.

3/8" Natural Pea Gravel is the lighter, finer stone version of the same trade, and it moves more readily than the larger rounded grade because the pieces are small and smooth.

Shredded mulch gives up permanence. In exchange it feeds the sand, it is easy to plant through, and it costs nothing to change your mind about. Beds with planting going on in them usually want mulch. Beds that are mostly architecture usually want stone.

Cubic yards for a 140-foot foundation bed, a border and four tree rings

Mulch is ordered here by the cubic yard rather than by weight. The mulch calculator takes length and width in feet and depth in inches, handles rectangles, circles and up to five separate areas, and adds five percent by default. It works (L x W x D/12) / 27 = cubic yards. Three hypothetical areas at a 3 inch depth:

• A foundation bed running 140 ft at 4 ft wide. 140 x 4 = 560 sq ft. 560 x 0.25 = 140 cubic feet. 140 / 27 = about 5.2 cubic yards.
• A border strip, 3 ft by 40 ft. 3 x 40 = 120 sq ft. 120 x 0.25 = 30 cubic feet. 30 / 27 = about 1.1 cubic yards.
• Four tree rings, each 6 ft across. A 6 ft circle is about 28 sq ft, so 4 rings are 112 sq ft. 112 x 0.25 = 28 cubic feet. 28 / 27 = about 1 cubic yard.

That is roughly 7.4 cubic yards for the three together, which at the published 600 lb per cubic yard is about 2.2 tons, a useful check when you are thinking about where a load will sit. Confirm your own areas on the mulch calculator, then choose a quantity and a delivery date on this page. Delivery is arranged at checkout by ZIP code and the truck needs a clear route to a spot it can tip. Pick that spot on a drive or a tarp rather than on grass, since a mulch pile left on a lawn for a weekend in summer will mark it.

A foundation drain, a low back corner and a ditch outfall want other materials

Three jobs get asked about on this page that mulch cannot do.

A French drain along a foundation is a stone detail. It needs open, washed aggregate that water can travel through, wrapped in filter fabric, which is Drain Rock rather than anything organic. Organic material in a trench rots, packs down and blocks the run.

A low back corner that ponds needs the grade raised, not covered. That is Fill Dirt placed and compacted in lifts, capped with Top Soil where grass has to grow.

A culvert outlet or a ditch that runs after a storm needs armor heavy enough that moving water cannot lift it. Mulch floats, and it will be downstream by morning. Use RipRap there. Mulch does hold bare ground on a gentle planted slope, but not anywhere water is channeled.