SCIENTIFIC NAME: Vaccinium corymbosum hybrid 'Sweetheart'

COMMON NAME: Sweetheart Hybrid Highbush Blueberry

GARDEN SIZE: 4-6 feet tall x 3-6 feet wide

GROWTH RATE: Reaches maturity in 6-8 years

USDA ZONE: 4-8

CHILL HOURS: 750-800

EXPOSURE: Full Sun

WATER & SOIL: Acidic, well-drained soil high in organic matter

HABIT (FORM): Upright, multi-stemmed woody shrub

FOLIAGE: Deciduous with blue-green leaves that turn red-orange in autumn

FLOWERS: Clusters of small, bell-shaped, pink and white flowers

BLOOM TIME: Spring

HARVEST TIME: Berries ripen during a concentrated period in late spring, followed in mild climates by a second, lighter harvest in early fall

POLLENIZATION: Highbush blueberries like Sweetheart are self-fertile and produces some fruit in isolation, but they produce a better crop with a compatible partner nearby. Plant near at least one other highbush blueberry of a different variety that blooms around the same time to encourage cross-pollenization.

POLLENIZATION PARTNERS: Recommended partners for Sweetheart include other late-blooming highbush cultivars like Blue Ribbon, Bluecrop, Blueray, Bountiful Baby, Mini Blues, and Top Shelf.

FRUIT: Abundant, medium to large berries with a frosty blue color and good flavor. Harvest promptly when ripe to avoid an overripe flavor. A mature bush can yield up to 15 pounds of berries each year.

CARE: When planting, condition the soil in an area twice the diameter of the root ball with peat moss or a soil conditioner like our Earthmix Landscape. Mix soil conditioner with existing soil in a 50/50 ratio.

Mulch with 2-6 inches of straw, wood chips, or other organic matter to help regulate moisture. Leave a gap of a few inches around the trunks to prevent damage to the stems from staying wet.

Blueberry bushes need about an inch of water every 7-10 days, though young bushes need a little more during their first growing season while they establish roots. If not enough rain has fallen, give a deep soak to the soil around the base of the plant once or twice per week. A good rule of thumb is 1 gallon of water per square foot of surface area under the canopy.

Fertilize each spring and fall with Holly-tone or another fertilizer made for acid-loving plants.

Prune in late winter to early spring while the plant is dormant. Remove weak canes and low-growing shoots that will be shaded by other limbs or touch the ground. If desired, cut taller canes down to within arm's reach to make it easier to harvest berries.

When your blueberry bush is about five years old, you may notice older canes becoming less productive. At this stage, begin cutting back 20% of the thick, gray, older branches to ground level each year. This will allow the canes to completely refresh themselves in a five year cycle.

PET SAFETY: May cause gastrointestinal issues in cats and dogs if consumed in large amounts, but not commonly eaten by pets. Always research further if you have concerns, as reactions can occur with anything. Also, remember to check the safety of any fertilizers or pesticides applied to your plants.

USES: Edible berries, hedges, borders, fall color

HISTORY: Like most newer blueberry varieties, Sweetheart's genes come from an assortment of different blueberries species. One parent is a northern highbush and the other a southern highbush, and overall it boasts about 15% Darrow’s evergreen DNA. Desirable for its early ripening time and concentrated harvest period, it was developed and tested by the Marucci Center for Blueberry & Cranberry Research and Extension, led by M.K. Ehlenfeldt in Chatsworth, New Jersey. The USDA-ARS released the new cultivar to the public in 2010. Though its original intent was commercial, Sweetheart’s abundant, sweet berries and the chance of a second harvest have won the hearts of many backyard growers.