Gardening With Organic Mulch

Mulching the garden. Mulch is any type of material that is spread or laid over the surface of the soil as a covering. It is used to:

  Retain moisture in the soil
  Suppress weeds
  Keep the soil cool
  Make the garden bed attractive
  Potentially improve the soil’s fertility

Examples of organic mulches include:

  Bark, Shredded or Chipped
  Composted Manure
  Grass Clippings
  Shredded Leaves

Organic mulch will decompose and have to be replaced, however in the process it will also improve your soil’s fertility and, of course, its organic content. The dryer and woodier the mulch, the slower it will decompose and the less nutrients it will give to the soil.

Organic Mulches


These are best used around trees, shrubs, and in garden beds where you won’t be doing a lot of digging. These woody mulches don’t mix well into the soil and it can become difficult to have to keep moving them aside to make way for new plants. They will last longer than finer organic mulches. Dyed wood mulch is made by grinding up old pallets and other trash wood, and may contain arsenic, creosote and other nasty stuff. It is the lowest quality mulch you can buy. As bark breaks down, it will remove nitrogen from the soil so an application of fertilzer before application may be wise.

Compost and Composted Manure

This can be used anywhere, as long as they are relatively well composted and weed free. You can use them as a coating of mulch or simply side dress plants with them during the growing season, to insulate and give a boost of slow released nutrients.

Grass Clippings

These are a mixed bag and are best suited to remote areas of your garden where you basically want to suppress weeds. Grass clippings, like most green plant debris with a high water content, decompose very rapidly and in the process, they can get somewhat slimy, with an unpleasant odor - so use with discretion. Grass clippings also tend to mat down and not allow water to pass through.


This mulch is becoming more and more popular. Most newspapers have switched over to organic dyes, especially for their black & white sections. Shredded newspaper has been used for years to keep plant roots moist while shipping. Layered sheets of newspaper also have great moisture retention abilities and they act like other organic mulches as far as suppressing weeds and controlling soil temperatures. They are also great for smothering existing grass, to jump start a new garden bed.

Shredded Leaves

Water after applying fish emulsion This is nature’s favorite mulch. Shredded leaves can be used as mulch anywhere and have the added bonus of being free. You will also entice more earthworms to your garden soil. Some gardeners don’t like the look of leaves in their garden and they probably aren’t appropriate for formal gardens. But if you spread a layer in the spring, before plants spread out, the leaf mulch tends to blend into the view within a short time.

Unshredded Leaves

These can mat together and repel water, in rainy areas. However if that happens, you can always rake and fluff them up a bit, if they appear to get matted.

Straw and Salt Hay

These are popular mulches for the vegetable garden. They keep the soil and soil diseases from splashing up on lower plant leaves and make paths less muddy. Straw decomposes very slowly and will last the entire growing season. It also makes a nice home for spiders and other beneficial insects who will move in and help keep the pest population in control. And finally, it’s easy to either rake up or work into the soil when it’s time to plant a new crop or put the vegetable garden to bed.

Applying Mulch

Do not extend the mulch right up to your home. Subterranean termites are in your landscape and mulch makes a perfect home for them. Always leave at least a six-inch clear area around your home.

Avoid touching a plant with any mulch. Mulches are for preventing weeds and retaining soil moisture; they do NOT keep plants warm or comfort them. Any mulch that's piled up against a plant stem or tree trunk provides cover and traps moisture, inviting pests, disease and rot to destroy that poor plant. Always leave a few inches wide open around the trunk or stem.

Dark-color mulches will absorb and retain more heat from the sun than light-color ones. This is an advantage in cooler regions but a disadvantage in hotter climates.

Light-color mulches (particularly decorative landscaping types, such as white s tones) reflect light and heat and can dangerously overheat surrounding plants.

Use mulch to protect plants during the winter. You can do this by pruning certain plants back and covering them entirely with mulch. The mulch provides insulation. Don't forget to remove the mulch in spring.

Prepare The Area

  Pull weeds or cut them close to the ground, if you are mulching for weed control. While not strictly necessary, it will help the mulch, and anything under it, to lay flat, and it will slow down the weed growth. Remember, mulch prevents weed growth by excluding light.
  Enrich the soil and dig the beds, if you plan to do so. Biodegradable mulch can break down into rich, loose soil without this preparation, but it will take time.
  Lay down anything you want under the mulch, such as landscaping fabric or plastic. Try adding several layers of newspaper or cardboard (remove tape and labels first) if you'd like a biodegradable means of blocking weeds.
  Install any borders or edges.
  Aim for at least two to four inches (5-10cm) of depth.

Further Information:

 Fall Garden Planning
 7 Ways to Use Fall Leaves
 How To Mulch Fall Leaves
 Leaf Mold: Gardener's Gold

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