What Happens If I Put Old Blueberries in the Soil of My Blueberry Bush?

Soil Conditions

• A common bond among all blueberry shrub species is their need for a highly acidic soil that is rich in organic matter. Plants develop rather shallow, fibrous roots in the top 14 inches of soil, so an evenly moist, nutritious and well-drained soil becomes important for long-term vitality of the plants. Blueberry shrubs should not have their root systems disturbed, and an organic mulch over the soil provides nutrients, deters weeds and shades the soil.

Blueberry Plant Debris

• Fallen blueberry leaves, twigs and berries all contribute to the nutritional value of the organic mulch layer over the soil. Usually, acid-forming mulch is used around blueberries to retain the low pH qualities. This includes pine bark nuggets, conifer wood sawdust, pine straw/needles, oak leaf mold or peat. Decomposing blueberry foliage and fruits also contribute to keep the soil pH in the range of 4.0 to 5.5. Sprinkling old blueberries picked from a plant or purchased at the farmer's market or grocery store is equally good for composting around plants.

Blueberry Fruit Placement

• Blueberry plant roots are shallow, so choosing to dig into the soil to discard old blueberries isn't worthwhile. Moreover, burying any organic matter slows its decomposition because there is limited oxygen for breakdown. Simply toss old blueberries atop the mulch around the base of your blueberry plants. They will decompose better, and the nutrients still trickle down into the root zone after rains and irrigation.

Caveats

• Don't pile old blueberries too deeply on the ground, as overly moist conditions can occur and lead to mold. Although it's not a major concern, you want ample air movement atop the mulch around blueberries, and excessive mold growths could indicate an environment more conducive for fungal issues. Large amounts of old blueberries poured around shrubs may also release a scent to lure wildlife into the garden to steal the fruits. In some parts of the country, bears, rabbits and deer may find a crop of blueberry fruits particularly alluring.