Organic Mulches:
- Compost is one of the best mulches for providing benefits to the soil, but that rich medium also provides a great place for weeds. Some compost is not very attractive. If apperance is important, use compost as a soil amendment and find a more visually pleasing material to cover it
- Wood Chips or Shavings are visually pleasing and provide all the characteistics of good mulch. Like sawdust, it is advisable to use older, decomposed material. Wood mulch that has not been properly aged or turned regularly can contain toxins and acids that are harmful to young plants. Fungal contamination can also occur with unseasoned wood mulch.
- Bark is also sold as chunks, nuggets, or shredded. Bark is one of the most attractive (and more expensive) mulch materials, so it may be best used in more visible areas. Pine, cedar, and cypress are the most common varieties. In addition to its appearance, bark provides good weed prevention and moisture retention. Plus, bark nuggets will last for years.
- Straw is the leftover stem portion of harvested grain. It is lightweight and therefore not always easy to apply. It tends to blow around. It decomposes quickly and therefore needs replacing more often than other mulches. Its appearance may not make it a top choice for the landscape. However, straw does make a good cover for newly seeded lawn areas.
- Hay, the stem portion of grasses, is often confused with straw. Hay is likely to contain weed seeds, so use it with caution. Both straw and hay are good plant nutrients and work well in the vegetable garden where weeds can easily be pulled.
- Pine Needles are sold in bales like straw which makes them relatively easy to transport and apply. They are long lasting and attractive.
Inorganic Mulches:
- Plastic warms the soil, plus blocks air and water. Plant growth is accelerated by the added heat and moisture retained underneath the mulch layer. Since plastic is solid, moisture must be provided by an irrigation system underneath or by careful hand watering. Usually sold in rolls, black or clear plastic can be used. Black is impervious to light, while clear plastic has been known to let weeds germinate and grow beneath. On the downside, plastic can overheat the plant’s roots or retain too much moisture, particularly if the plastic is covered with a layer of organic mulch for apperance sake. Plastic will freeze, so you may need to take it up in the fall. If used on slopes, any material placed on top of plastic will wash away or slide off. Plastic is well suited for use in vegetable gardens.
- Brick or Stone offers a neat apperance but may not blend with every landscape design. They offer some weed control. Brick and stone (especially lighter shades) will reflect heat back up towards plants, which may be harmful. This mulch is certainly long lasting. Be careful – if pieces are strewn into the lawn, they can become potential hazards when mowing.
- Landscape Fabric is purchased in rolls and provides good weed control. Plus, unlike plastic, the fabric allows air and moisture to
penetrate into the soil and plant roots. Overall, it’s the best inorganic mulch for long-term use. Roots can become enmeshed in the fabric, making removal difficult, so be sure to remove weeds as soon as you see them.