
©National Cocoa Shell Dist., Inc.
National Cocoa Shell Dist., Inc.
One of gardening’s secret weapons is mulch. It’s not a glamorous starlet that steals the spotlight, but its performance can make or break a landscape design. Whether you’re grooming a fabulous front yard or raising your family’s favorite veggies in the backyard, mulch can make each planting area healthy, earth-friendly and beautiful.
Why Use Mulch
How does mulch benefit the landscape?
- It suppresses weeds and makes weeds that do sprout easier to pull.
- It slows water evaporation from soil, so you don’t have to water as often.
- It insulates soil against temperature extremes. This protects shallow-rooted plants in cold regions and coddles crops as summer sizzles.
- It prevents soil compaction during downpours. Loose, uncompacted soil yields happy, healthy plant roots.
- It slows storm water runoff and helps reduce soil erosion. Less runoff means planting beds are absorbing more rain.
- It prevents disease organisms from splashing from soil to plant leaves, which reduces disease outbreaks.
- It gives planting beds a polished look, enhancing even the most basic landscape design.
Types of Mulch
Mulch falls into two general categories: organic and inorganic. Both types contribute good looks to a garden design.
- Organic materials include things like shredded bark, pine straw, compost or grass clippings. These materials break down over time, adding organic matter to soil and improving it.
- Inorganic mulches are more permanent and don’t readily degrade. Stone, weed fabric, rubber or geotextile mats are types of inorganic mulches.
How to Mulch
Step 1: Thickness
Apply a 2- to 3-inch-thick mulch layer. If you’re gardening in slow-draining soil, use a thinner layer (1 to 2 inches); for fast-draining soils like sand, aim for 4 inches. A too-thick layer can lead to plant rot, diseases, pests and rodents.
Step 2: Placement
Extend mulch beyond the plant’s drip line — the point where the outermost edge of leaves occurs. To prevent rot, pull mulch back 2 to 4 inches from perennial crowns, shrub stems and tree trunks.
Step 3: Water
Water mulch after application. This keeps dry mulch from absorbing soil moisture (and stealing it from plant roots). Second, it helps anchor lightweight mulches easily carried by wind.
©Julie A. Martens
Julie A. Martens
When to Mulch
Apply mulch year round in every climate. In the coldest regions, to protect overwintering plants, apply mulch after the ground freezes. To insulate soil against summer heat, apply mulch in late spring after soil warms.
Organic mulches break down through the growing season — faster in warmer regions. Typically, you’ll have to re-apply organic mulch annually. Check mulch thickness occasionally; replenish as needed.
Shopping for Mulch
You’ll find the best mulch bargains when you buy in bulk, but that means you’ll need a pickup truck. Bagged mulches can be easier to transport and may be the best deal for small front yard beds or modest backyard planting areas. Most stores give discounts for broken bags; ask at the register.
Good organic mulch should have an earthy, damp odor. If you smell ammonia, vinegar, alcohol or sulfur, don’t buy that mulch. It could actually harm plants.
Find the Right Mulch
The perfect mulch:
- doesn’t compact
- decomposes relatively slowly
- is water- and air-permeable
- is fire-resistant
Every mulch type offers distinct advantages. How can you choose the one that’s right for your gardening situation? Learn more about different mulches in our Landscape Mulch Gallery.