Culture
Best grown in acidic (pH of 4.8 to 5.2), organically rich, medium to wet, well-drained soils in full sun to part shade. Shallow, fibrous roots need constant moisture and good drainage. Plants appreciate a good organic mulch. Although blueberries are self-fertile, cross-pollination produces the best fruit crop (larger berries and larger yields). Therefore, it is best to plant more than one variety that will bloom at the same time. In addition, blueberry season can be extended by planting early, mid-season and late varieties which will collectively ripen from early June to the end of the summer (St. Louis area). Best to remove flowers from plants in the year of planting and in the following year so as to prevent fruit set and to encourage new vegetative growth. Prune as needed in late winter beginning in the third year after planting.
Noteworthy Characteristics
Vaccinium corymbosum, commonly known as highbush blueberry, is an upright, deciduous shrub native to eastern North America where it typically grows in moist woods, bogs, swamps and low areas. Mature plants will reach around 5-8’ tall with an equal spread and a dense, rounded habit. The dark green, ovate to elliptic foliage can reach 3" long and 1" wide and turns bright shades of coppery red in fall. Loose corymbs of white, pendulous, urn-shaped flowers bloom in spring. The flowers can also have a pale pink tinge. The round, sweet berries are dark blue to purple with a dull, blue-grey bloom on their surface.
The genus name Vaccinium comes from an ancient Latin name apparently derived from a prehistoric Mediterranean language. Its origin and meaning are generally considered to be lost to time.
Specific epithet refers to the flowers and fruits being in a corymb.
'Herbert' produces medium blue blueberries which are unusually large (to 7/8" diameter) and which ripen in late mid-season (mid to late July in USDA Zone 5). Ovate, dark green leaves (to 3.5" long) turn attractive shades of red in fall. Reddish stems can be attractive in winter. 'Herbert' grows well in Missouri.
Problems
Birds love the fruit, so plants may need to be covered with netting as the fruit begins to ripen in order to protect the crop. Chlorosis (yellowing of leaves) may occur in high pH (alkaline) soils. Potential but infrequent disease problems include stem blight, root rot, anthracnose, cane cankers, mildew and botrytis. Blueberry maggot, cherry fruit worm and spotted wing drosophila may attack the fruit. Mummy berry is a fungal disease that causes the berries to shrivel and drop.
Uses
Useful for ornamental purposes (flowers, fruit, quality summer foliage and fall color) as well as for fruit production (blueberries). It is effective in shrub borders or as part of less formal shrub plantings in areas such as native plant gardens or open woodlands. Particularly effective in conjunction with rhododendrons and azaleas which share similar acidic soil requirements. Also makes an excellent hedge with the added benefits of fruit which can be harvested or left for the birds.