Blueberry, Hybrid Highbush 'Sweetheart' (2-year, 16-20 inch, 1-liter)

Key Characteristics

• Origin: 'Sweetheart' is a vigorous Northern-Southern Highbush blueberry hybrid (Vaccinium corymbosum) developed in 1999 and introduced in 2010. It was bred to produce a heavy early crop and, in mild areas, a lighter second crop in the same year.
• Patent Status: The patent status of 'Sweetheart' Blueberry needs to be verified. As it was introduced in 2010, it is highly likely to be protected by a U.S. Plant Patent, but we were unable to verify this.
• Berry Production: Produces medium to large, sweet, and juicy blue berries. It is known for yielding up to 15 pounds of blueberries per plant annually, with two crops in warmer climates. The first heavy crop ripens early in the season, followed by a lighter second crop.
• Ripening Time: The first heavy crop typically ripens in late May to early June. A lighter second crop ripens in August in mild areas.
• Plant Size and Appearance: 'Sweetheart' is a bushy, upright deciduous shrub that grows to a mature height of 5 to 6 feet and a spread of 3 to 4 feet. It has oval, dark green leaves that turn brilliant red shades in the fall. In spring, it displays bell-shaped, white flowers, sometimes with pink tinges.
• Flowers: Features petite bell-shaped white flowers in the spring, sometimes described as white and pink blossoms.
• Hardiness: 'Sweetheart' is cold-hardy and generally adapted to USDA Zones 4 through 8.
• Pollination: While considered self-pollinating, planting more than one 'Sweetheart' Blueberry bush or another compatible Northern Highbush variety with the same bloom time is recommended for optimal pollination, resulting in larger berries and increased yields.
• Growing Conditions:
  • Sunlight: Thrives in full sun (6 to 8 hours per day) but can tolerate partial shade. More sun leads to better fruit production and sweeter berries.
  • Soil: Prefers well-drained, moisture-retentive, organically rich, acidic soil with a pH between 4.5 and 5.5. Amend soil with peat moss and other organic matter to increase acidity and improve drainage.
  • Watering: Requires regular watering, especially after planting and during fruit development. Keep the soil consistently moist but not waterlogged. Mulching around the base of the plant helps retain moisture and regulate soil temperature.
  • Fertilizing: Fertilize in early spring with an acid-forming fertilizer specifically formulated for blueberries. A second light fertilization can be done after the first harvest. Avoid over-fertilizing.
  • Pruning: Prune as needed in late winter or early spring, beginning in the third year after planting. Remove any dead, damaged, or crossing branches. Thin out older canes to encourage new, productive growth and maintain an open center for good air circulation. Lower limbs can be thinned to prevent fruit from touching the soil.
• Uses: The sweet and juicy berries are excellent for:
  • Fresh eating
  • Baking into pies, muffins, and other desserts
  • Making jams, jellies, and preserves
  • Freezing for later use
• Wildlife Value: The spring flowers attract pollinators like bees, and the berries are a food source for birds. Bird netting may be necessary to protect the developing fruit.
• Ornamental Value: 'Sweetheart' offers year-round interest with its spring blossoms, attractive green foliage, abundant summer berries, and brilliant red fall color. Its upright, bushy habit makes it suitable for borders, hedges, or as a standalone specimen. It can also be grown in containers.
• Disease and Pest Resistance: 'Sweetheart' is reported to have no serious pest or disease issues. However, it's good practice to monitor for common blueberry pests and diseases like powdery mildew and vine weevil and address them if they occur. Ensuring proper soil drainage and air circulation can help prevent fungal diseases. Chlorosis (manganese and iron deficiencies) can occur in soils that are not acidic enough.