Abstract: A soil amendment is disclosed containing, by volume, about 20 to 60% cross-cut redwood grains or ground redwood bark of a particle size substantially in the range of 0.5 to 3 mm, about 15 to 50% grape pumice, about 0 to 20% cross-cut fir grains of a particle size substantially in the range of 0.5 to 3 mm, about 0 to 20% agricultural pumice and about 0 to 25% aged whole rice hulls.