The Best Soil & Fertilizer Products for Hedges (2026)

Most 'plant food' marketing is noise. A hedge needs five things from the soil side, and Southern California garden centers stock excellent versions of all of them. Here's the honest shopping list.

1. Compost — the non-negotiable

LA clay and OC sandy loams both improve the same way: organic matter. Kellogg Amend and Gromulch are the SoCal shelf staples and genuinely good; any well-finished local compost works. We amend every trench we plant — if you're feeding an existing hedge, top-dress an inch under the mulch each spring.

2. A balanced organic fertilizer

Slow, steady nitrogen beats surge feeding for dense hedge growth. E.B. Stone Organics and Dr. Earth all-purpose blends are the reliable California picks; Osmocote slow-release is the fine synthetic alternative. Feed in early spring and early fall; skip midsummer heat waves.

3. Mycorrhizal inoculant at planting

Root-zone fungi that extend a new tree's effective root system. Strong evidence at transplant time (we use it in the planting mix); marginal value sprinkled on an established hedge — buy it for planting day, not maintenance.

4. Gypsum for heavy clay

Not magic, but genuinely useful in compacted LA clay: improves structure and drainage over repeated applications without changing pH. Cheap insurance in Valley and Eastside soils.

5. Three inches of bark mulch

The highest-ROI product on this list: walk-on fir bark over the root zone conserves water, blocks weeds, and feeds the soil as it breaks down. Keep it a hand-width off the trunks. (Our top-dress add-on installs exactly this at $7/ft.)