Kelly Jackson
Christian County Exension Office
Backyard Blueberries
Blueberries are an easy-to-grow native fruit with few pests that do well across Kentucky. With the right care, you can expect well-established plants to yield 6 to 15 pounds of delicious berries every year for many years. The key to growing blueberries successfully begins with the soil.
Like most fruit crops, blueberries need good airflow. A site with a higher elevation than the surrounding area is idea. But the real struggle most home gardeners have is adjusting soil pH to an acceptable level. Blueberries, like azalea and rhododendron, are ericaceous plants needing a highly organic well-drained soil with a pH of 4.5 to 5.2. Comparatively, home lawns and gardens do best at 6.5, much too alkaline for blueberries. Also our soils tend to be too compacted and poorly drained for blueberries to do well. Therefore, some improvements must be made before you plant (before being the key word).
Starting with a soil test, determine your soil’s pH level. You will most likely need to add finely ground sulfur or aluminum sulfate to lower the pH to optimum levels. These products need to incorporated into the top 2 to 3 inches of soil at the rate recommended on the soil test at least 60 days before planting. Also plan to retest the planting area for the next several years to be sure the pH remains in the correct range. If soil is compacted, you can improved the soil structure by tilling in organic matter or by using green manure crops before planting. Skipping the soil prep will cause your plants to turn yellow and grow poorly, if they grow at all.
Plant blueberries in early spring before growth starts or in late fall after frost. You can purchase plants as either dormant bare root plants or as potted plants. Recent research shows that holes dug 18 inches wide and 24 inches deep yielded plants that produced better than others. Peat moss can be mixed with the native soil in the bottom of the hole. Blueberries should be planted at the same depth as they grew in the nursery with roots well spread out and soil packed firmly around the roots. Do not add any fertilizer to the planting hole. Instead wait for bloom and side-dress with 0.1 lb. of ammonium sulfate per plant. Repeat about six weeks later.
Blueberries should also be mulched with organic mulch like sawdust, wood chips, pine needles or straw at a depth of 4 to 6 inches. Mulching moderates soil temperature fluctuations and substantially increases the growth of young plants. Because blueberries are very inefficient at absorbing water, consider installing a trickle irrigation system or soaker hoses, being careful not to overwater. Blueberries can be grown without irrigation but research shows yields more than double with it.
There are many great varieties of blueberries. Our area is best for growing highbush (Vaccinium corymbosum) cultivars because they are better suited to survive our low winter temperatures than rabbiteye (V. ashei) blueberries. The list below includes some recommended highbush cultivars:
• Duke: An early maturing large berry. It is one of the heaviest, most consistent producers often yielding 20 pounds per bush when mature.
• Patriot: Selected by the University of Main for cold hardiness. Yields 10 to 20 pounds of fruit and is a little more forgiving on wetter soils than other blueberries. It also has showy white blooms and great fall color making it a good selection for your existing landscape beds.
• Bluejay: Extremely vigorous variety growing almost twice as fast as other blueberries. Berries can remain on the plant for long periods of time without losing quality.
• Bluecrop: Considered the best all-around variety for consistent yields, large high quality fruit and disease resistance.
• Nelson: A very productive mid-season berry with a mildly sweet flavor.
• Elliott: A very late tangy berry helping to extend your blueberry harvest into September.