Mulching with organic materials, such as pine bark, pine needles, leaves, hay, wood chips, sawdust or other organic materials is very beneficial for soil health. Well-maintained mulch can help control weeds, and keep soil cool, loose and uniformly moist. Mulch should be 4 inches to 6 inches deep and cover a 4-foot band of soil centered on a blueberry plant row. It is important to replenish mulch as it deteriorates. Deteriorating mulch adds organic matter to the soil and creates a favorable environment for root growth. Vigorous root growth can cause root exposure if mulch is not replenished as it deteriorates. The benefits of mulching continue as long as mulch is replenished when necessary.
Sawdust can be used as mulching material, particularly a well composted softwood sawdust. If fresh sawdust is used, an additional 50 percent to 100 percent Nitrogen may be necessary for the first few years to compensate for increased microbial activity. Well-composted sawdust requires less supplemental nitrogen. In addition to its use as mulch, composted sawdust has been found beneficial when applied in the planting hole, particularly in conjunction with the mulch. In these cases fertilizer applications has to be increased threefold to produce vigorous growth. Also, it is possible to overcome the harmful effects of high soil pH by incorporating sawdust into the soil in which rabbiteye blueberries were grown. The incorporation of peat moss in the soil at planting also provides higher yields in following years.
A preplant soil test will help to measure the levels of important nutrients such as phosphorus, potassium, calcium, and magnesium. Some adjustments for these elements are done most effectively if they are incorporated before planting. Organic matter content of the sopil may be increased by incorporating a cover crop with the soil and by adding rotted, peat moss, manure (except poultry), leaf mold, or ground pine bark.
Use of raised beds may increase the acceptability of sites with marginal aeration or drainage. Raised beds may also compensate, in part, for the sinking of plants that occurs as organic matter decays in the planting hole. Such sinking may increase the risk of certain diseases