Bulbs
Flower Basics
Flower Beds & Specialty Gardens
Flower Garden
Garden Furniture
Garden Gnomes
Garden Seeds
Garden Sheds
Garden Statues
Garden Tools & Supplies
Gardening Basics
Green & Organic
Groundcovers & Vines
Growing Annuals
Growing Basil
Growing Beans
Growing Berries
Growing Blueberries
Growing Cactus
Growing Corn
Growing Cotton
Growing Edibles
Growing Flowers
Growing Garlic
Growing Grapes
Growing Grass
Growing Herbs
Growing Jasmine
Growing Mint
Growing Mushrooms
Orchids
Growing Peanuts
Growing Perennials
Growing Plants
Growing Rosemary
Growing Roses
Growing Strawberries
Growing Sunflowers
Growing Thyme
Growing Tomatoes
Growing Tulips
Growing Vegetables
Herb Basics
Herb Garden
Indoor Growing
Landscaping Basics
Landscaping Patios
Landscaping Plants
Landscaping Shrubs
Landscaping Trees
Landscaping Walks & Pathways
Lawn Basics
Lawn Maintenance
Lawn Mowers
Lawn Ornaments
Lawn Planting
Lawn Tools
Outdoor Growing
Overall Landscape Planning
Pests, Weeds & Problems
Plant Basics
Rock Garden
Rose Garden
Shrubs
Soil
Specialty Gardens
Trees
Vegetable Garden
Yard Maintenance
How Thick to Mulch
How Thick to Mulch. Mulch is the saving grace for weed-weary gardeners. Not only does mulch suppress rogue dandelions, it also conserves soil moisture, insulates roots and simply adds a tailored, cared-for appearance to your garden. Mulch thickness is key to success -- deep mulches smother roots or increase disease, while thin mulches disappear...
Mulch is the saving grace for weed-weary gardeners. Not only does mulch suppress rogue dandelions, it also conserves soil moisture, insulates roots and simply adds a tailored, cared-for appearance to your garden. Mulch thickness is key to success -- deep mulches smother roots or increase disease, while thin mulches disappear under weeds and dusty soil.
Mulch Varieties
Mulch thickness depends on the type of mulch you select for your basic, permanent application. Fine or flat mulches, such as lawn clippings, settle tightly together and can prevent water from entering the soil or smother roots if the mulch, after settling, is more than 2 inches thick. On the other hand, mulches with large chunks or coarse textures allow greater air and water movement. These mulches, such as bark chips, are effective when you spread them 3 to 4 inches thick.
Location
Sandy soils lose water more quickly than heavy soils and benefit from slightly deeper mulch. The same 3-inch layer of mulch over clay soil, however, prevents air circulation, suffocates surface roots and may encourage root rot or other fungal growth. Examine your garden and the soil, taking into account summer sunshine or shady, moist areas, and adjust your mulch depth accordingly. Also, keep mulch 1 to 2 inches away from tree trunks or plant bases.
Seasonal Mulching
If you experience harsh winters or dry summers, you probably add an insulating seasonal mulch to your garden. Contrary to common belief, winter mulch does not insulate the ground from the cold. Rather, it prevents the frozen ground from thawing, keeping the plants safe in their dormant state. Don't add a winter mulch until the ground freezes. A 6- to 8-inch layer of straw is a light, insulating mulch for winter flower beds or summer vegetable gardens.
Reapplying Mulch
As a general rule-of-thumb, most mulches are 2 to 2 1/2 inches thick. Organic mulches decompose, improving the soil but gradually removing the protective layer from your garden. Don't add another 2 to 3 inches of mulch over your old layer, however. Instead, top-dress the existing mulch with new mulch until it returns to the original thickness. Depending on your climate and the mulch variety, your mulch may remain effective for many seasons or need renewal every six months.
