If your shrubs and perennials are looking a little tired—despite regular watering and mulching—you might be missing a critical step in their care: replenishing the soil’s nutrients. Over time, even the most well-maintained landscape beds can become depleted, especially when wood mulch is involved.

At Tim Wallace Soil Mix Supply, we know healthy soil means healthy plants. That’s why we recommend a simple, effective way to revive your landscape beds each year—with compost, a balanced fertilizer like 10-10-10, and a bit of hands-on attention.

The Hidden Cost of Mulch: Nitrogen Depletion

Wood mulch has long been a favorite for moisture retention, weed suppression, and aesthetics. But did you know that as it breaks down, it uses up nitrogen in the soil?

Here’s why: the decomposition of wood-based mulch is driven by soil microbes, and these microbes require nitrogen to do their job. As they digest the carbon-rich mulch, they draw nitrogen from the surrounding soil—the same nitrogen your plants need to grow strong and green.

Without replacement, this slow drain of nutrients can weaken your shrubs and perennials, leading to stunted growth, pale foliage, and fewer blooms.

The Smart Solution: Compost + 10-10-10 Fertilizer

To counteract this natural process, we recommend a two-part strategy that restores the soil’s balance and feeds your plants in a sustainable way:

• Compost enriches the soil with organic matter and a wide spectrum of micronutrients. It also improves soil structure, moisture retention, and microbial life—all critical for plant health.
• 10-10-10 all-purpose granular fertilizer delivers a balanced dose of the three primary nutrients right to your plants:

• Nitrogen (N) for lush, green foliage,
• Phosphorus (P) for strong roots and vibrant blooms,
• Potassium (K) for resilience against stress and disease.

Remember: Compost feeds the soil. Fertilizer feeds the plant. Together, compost and 10-10-10 fertilizer provide both the slow, steady support of organic material and the immediate nutrient boost of granular fertilizer.

The “Trench” Method: Targeted Nutrition for Shrubs

For established shrubs and woody perennials, we recommend the trench method—a simple, hands-on technique that delivers nutrients right where plants need them most.

Here’s how to do it:

1. Pull mulch away from the base of each shrub.

2. Dig a shallow trench around the plant’s drip line (the outer edge of its branches).
3. Add compost and fertilizer:
4. Drop in 2–3 garden shovels of compost.
5. Sprinkle in a few tablespoons of 10-10-10 fertilizer.
6. Return the original soil and mulch to the trench.
7. Water gently to activate the nutrients and help them soak into the root zone.

This method minimizes root disturbance while enriching the soil exactly where the plant can access it.

For Leafy Perennials: A Springtime Boost

For soft-stemmed perennials like Hosta, ferns, Russian sage, and salvia, which die back in fall and re-emerge in spring, a lighter touch works best.

Once you see new growth pushing up from the soil:

• Sprinkle about 1 cup of compost around the base of each plant.
• Add a few tablespoons of 10-10-10 fertilizer.
• Let spring rains slowly wash these nutrients into the soil.

This top-dressing approach feeds plants gradually and supports a strong start to the growing season.

Why This Works

This process isn’t just about nutrients—it’s about rebuilding the entire soil ecosystem:

• Compost boosts beneficial microbial activity and improves soil structure.
• Fertilizer ensures immediate nutrient availability for robust growth.
• Mulch (once the nutrient deficit is addressed) continues to protect and insulate the soil.
• Water activates the entire process and ensures nutrients are delivered where they’re needed.

Ready to Give Your Plants What They Need? Don’t let depleted soil hold your landscape back. Your plants give their best when the soil does too, so give them the nourishment they deserve. Stop by today to check out our 5 different bulk compost options.