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• Mulching conserves soil moisture. A 2"-3" cover of mulch forms a protective layer over the soil that slows the evaporation of water and keeps prevents the soil from drying out too quickly. This saves water by significantly reducing the amount of water required and the frequency of irrigation.
• Mulching greatly helps with weed control. In general, weed seeds that drop on mulch are less likely to germinate. You will find that the time you spend weeding your beds will be greatly reduced. Mulches that breakdown quickly will act as soil for weed seeds and are not as effective for weed suppression.
• Mulching moderates soil temperature. A layer of mulch will help maintain a more constant soil temperature. Summer soil temperatures will be significantly lower in a mulched garden bed that one with just bare soil.
• Mulching with an organic mulch improves soil structure. As organic mulches breakdown, they add organic matter back into the soil. This improves the soil not only by adding nutrients to the soil, but also increasing the water and nutrient holding capacity of your soil.
• Mulch puts an attractive finishing touch to the garden!

• Mulch should be applied to a total depth of 2"-3". If you are replenishing mulch on an existing bed, be careful not to over-mulch - the 2"-3" layer should include any mulch still present on the garden.
• Over-mulching can cause soil compaction which reduces aeration of the soil and keeps the soil too moist. This can lead to root rot and other disease problems.

• Pine needle mulch

  Pine mulches, which include pine bark, shredded pine bark, or pine needles (a.k.a. pine straw), are the longest lasting natural mulches. These mulches can last 14 months.
  A common misconception is that pine mulches will lower the pH of (acidify) your soil. Research has shown that this is not the case. In order to affect the pH significantly, a mulch has to breakdown quickly. Pine mulch breaks down slowly and the change in soil pH is negligible.
• Hardwood bark mulches are good but do not last as long as the pine mulches.
• Wood chips, such as you might get from chipping trees and branches, are not a good garden mulch. These are mainly composed of heartwood and sapwood which break down quickly and rob the soil of nitrogen as they decompose. If you use wood chips you will need to add replenish the nitrogen by adding extra fertilizer to the bed.
• Raked leaves are great for the compost pile but not the best as a mulch because they mat down blocking soil and water penetration to the soil and can smother your plants. Shredded leaves breakdown too quickly and make a great place for the germination of weed seeds.
• Straw is also quick to breakdown and is often filled with grain seeds that will sprout throughout your garden.