Organic Mulches

Examples of organic mulches include:

• Bark, Shredded or Chipped
• Compost
• Composted Manure
• Grass Clippings
• Newspaper
• Shredded Leaves
• Straw

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. Generally the dryer and woodier the mulch, the slower it will decompose and the less nutrients it will give to the soil.

• Bark mulches are best used around trees, shrubs and in garden beds where you won’t be doing a lot of digging, like front walkways and foundation plantings. These woody mulches don’t mix well into the soil and it can become a hassle to have to keep moving them aside to make way for new plants.
• Compost and Composted Manure 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 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. 
• Ideally you should use a mulching mower and leave the clippings on the lawn to add fertility to that soil. However if you do bag your grass clippings, don’t throw them away unless you have used weed killer or some other pesticide on your lawn. Synthetic lawn care products can be bad for some flowers and you certainly don’t want to use them in your vegetable garden. But untreated grass clippings can either be dumped into your compost bin or used to mulch open, unplanted areas.
• Newspaper as 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.
• To use as a mulch in the garden, spread a layer of 4 - 8 sheets of newspaper around the plants. Moisten the sheets to keep them in place. On windy days it’s easier to moisten the sheets before you place them down. Cover the newspaper with a 1-3 inch layer of another organic mulch and the weed protection should last throughout the growing season.
• Shredded Leaves are natures favorite mulch. Shredded leaves can be used as mulch anywhere and have the added bonus of being free. I have never had so many earth worms in my flower gardens as I’ve had since I started using shredded leaf mulch about 3 years ago. Even my compost pile doesn’t have as much activity as under these leaves.
• 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. Shredded leaves are perfect for woodland gardens and I always spread a layer over my vegetable garden in the fall, to begin decomposing over the winter.
  Unshredded leaves can mat together and repel water, in rainy areas. But I have to confess that if my leaves get too wet to shred, I’ll use them as mulch anyway and simply stir them up a bit if they appear to get matted.
  
• Straw and Salt Hay are popular mulches for the vegetable garden. They keep the soil and soil born 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. 
•  Whatever mulch you choose, apply it soon after planting, before new weeds sprout. Apply a 2-4 inch thick layer of mulch, avoiding direct contact with the plant stems. Piling mulch around the stem can lead to rotting and can provide cover for munching mice and voles.