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If you open a new bag of soil or mulch and find white mold or fungal spots, it's a direct result of moisture content. Mold and fungus thrive in moist environments containing organic matter. Since soil and mulch bags are not always perfectly waterproof, water content from the original packaging (especially in colored mulch, which retains moisture from the dyeing process) or moisture seeping in after packaging provides the ideal conditions for these harmless organisms to develop.
The mold and fungus found in soil or mulch bags are generally harmless. They are natural organisms that help break down organic matter and contribute to the health of your garden, rather than damaging your plants. They pose no risk to people or pets, though wearing gloves when gardening is always a good idea.
If you see mold on the exterior of a bag of soil or mulch, do not purchase it. This may indicate improper storage conditions and potential contamination. Unlike mold found inside the bag (which is often harmless), external mold suggests a compromised product.
Fungi, including mold and mushrooms, are essential components of a healthy soil ecosystem. These beneficial microorganisms perform a vital function: they break down organic material into readily available nutrients that your plants can easily absorb. This process is so crucial that we deliberately choose not to sterilize our growing media, ensuring we preserve these natural helpers that enrich the soil and foster balanced conditions for robust plant roots.
If you notice a large, unattractive amount of mold, it's typically a sign that the soil or mulch is too wet. While this overgrowth is not harmful to your plants, you can easily reduce or eliminate it by exposing the media to sunlight and air.
The mold should naturally dissipate once the moisture level decreases. Remember to always wear gloves when handling any growing media product.
Since moisture is the main driver of mold growth inside bags, choosing a product with lower water content will help. We recommend Miracle-Gro Organic™ All Natural Mulch. This product is undyed, meaning it carries less residual moisture from the coloring process, which in turn leads to less mold development. Even if you see some mold in any mulch or soil, remember it's a natural occurrence that helps enrich your garden.
Mulch is the key to achieving a finished, professional look in your yard. It immediately adds rich color and texture to areas like landscape beds, around trees and shrubs, or along your home's foundation. Choosing a colored mulch offers the added benefit of beautifully accenting and harmonizing with the existing colors of your home and flower gardens.
Mulches made from wood and other organic materials are valuable because they actively improve the soil as they decompose. Over time, natural soil inhabitants like microbes and insects consume the mulch. The by-products of this natural consumption are released back into the soil as organic matter, leading to healthier, more fertile growing conditions.
Mulch functions as an effective insulator, playing a critical role in regulating soil temperature throughout the year. It keeps plant roots cool during the heat of summer and provides essential warmth and protection during the winter months. This insulating property is particularly vital for tender, new plantings established in the fall, offering necessary defense as temperatures begin to drop dramatically.
Mulching directly contributes to reduced watering time because it acts as a barrier to moisture evaporation. By slowing down this process, mulch ensures that more water remains conserved in the soil, readily available to nourish thirsty plant roots.
Applying a 2 to 3-inch layer of mulch provides a natural, effective barrier against weeds. This works by blocking sunlight and physically suppressing growth, which prevents weed seeds from sprouting and taking over your landscape beds.
Mulches come in various forms (wood, rock, synthetic), but to gain the essential benefit of soil improvement, consider choosing a wood mulch. Premium options like Scotts® Nature Scapes® Color Enhanced Mulch and Scotts® Nature Scapes® Triple Shred Mulch are made from natural forest materials, offering rich color that lasts up to a year. When choosing a color, select a hue that complements your home (e.g., brown or red for brick). While darker mulch makes flowers stand out, be aware that black mulches absorb heat, so lighter colors are recommended in very warm climates to prevent plant overheating. Overall, mulching is a quick and simple way to enhance your landscape and improve the growing environment.
| Number of 1.5CF Bags | Coverage at 3" Depth |
|---|---|
|
1 |
6 sq. ft. |
|
2 |
12 sq. ft. |
|
4 |
24 sq. ft. |
|
6 |
36 sq. ft. |
In most situations, there is no need to remove old mulch since it will naturally decompose and enrich your soil. The only time removal is necessary is if the layer is excessively thick (over 4 inches). If you choose to leave the old mulch, always be sure to loosen it up before adding a new layer. This simple step is vital for improving both drainage and airflow in the soil beneath.
As a general rule, applying fresh mulch to your landscape or garden beds once a year is recommended.
Arugula, leeks, lettuce, onions, radishes, spinach, strawberries, basil, chives, cilantro, dill, mint, oregano, parsley, thyme, marigolds and other annual flowers
Beans, beets, broccoli, Brussels sprouts, cabbage, cantaloupe, carrots, cauliflower, collards, cucumbers, garlic, kale, summer squash, Swiss chard, turnips, lavender, rosemary, sage, borage, calendula, cosmos, lantana, nasturtiums, snapdragons, sweet alyssum (plus everything in the 6" list)
Artichokes, asparagus, eggplant, okra, parsnips, peppers, sweet potatoes, tomatoes, watermelon, winter squash, pineapple sage (plus everything in the 6" and 12" lists)
Start feeding your plants with Miracle-Gro® Raised Bed Plant Food one month after planting, following label directions. This combination, particularly when using Miracle-Gro® Raised Bed Soil, guarantees more abundant yields (compared to unfed plants). For subsequent planting seasons, instead of replacing all the soil, simply renew it. Before planting, mix in Miracle-Gro® Refresh™ Soil Revitalizer as directed. It is designed to rebuild soil structure, enhance water retention, and replenish essential nutrients, keeping your garden beautiful and productive.
| Area | 6" | 12" | 20" |
|---|---|---|---|
|
2ft. x 2ft. Bed |
2 Bags 1.5CF 2 Bags 1CF |
3 Bags 1.5CF 4 Bags 1CF |
5 Bags 1.5CF 7 Bags 1CF |
|
4ft. x 4ft. Bed |
6 Bags 1.5CF 8 Bags 1CF |
11 Bags 1.5CF 16 Bags 1CF |
18 Bags 1.5CF 27 Bags 1CF |
|
4ft. x 8ft. Bed |
11 Bags 1.5CF 16 Bags 1CF |
22 Bags 1.5CF 32 Bags 1CF |
36 Bags 1.5CF 54 Bags 1CF |
| Area (sq. ft.) | 3" Depth |
|---|---|
|
24 sq. ft. |
4 Bags 1.5CF 6 Bags 1CF |
|
48 sq. ft. |
8 Bags 1.5CF 12 Bags 1CF |
|
72 sq. ft. |
12 Bags 1.5CF 18 Bags 1CF |