Sharpblue Blueberry

Sharpblue is a southern highbush blueberry released by the University of Florida blueberry breeding program in 1976 — the first southern highbush cultivar ever released and the founding cultivar of the Florida blueberry industry. It was developed under the direction of Dr. Ralph Sharpe, who initiated blueberry breeding at UF in 1950 with the explicit goal of producing cultivars adapted to Florida’s mild winters and high-heat summers. The breeding strategy combined large-berry, high-quality Vaccinium corymbosum genetics with V. darrowi Camp, the native Florida evergreen blueberry, through recurrent selection over multiple generations; the specific parental cross for Sharpblue has not been formally documented. Sharpblue, Flordablue, and Avonblue were released simultaneously in 1976 and 1977 as the first fruits of that 25-year program. Sharpblue proved the most commercially durable of the three and for decades served as the benchmark against which all subsequent Florida introductions were measured — a role analogous to TifBlue among rabbiteye cultivars. It remains unpatented and is widely grown from Florida through coastal Texas and into international markets with similar subtropical climates.

Sharpblue Southern Highbush blueberry is best suited to USDA Zones 8–10 and thrives on as few as 150–200 chill hours, making it among the most heat-adapted varieties available. Soil pH must be maintained between 4.5 and 5.0 — even slightly alkaline soils cause chlorosis and stunted growth. Sandy, well-drained soils amended with pine bark or peat are ideal. Mulch heavily with pine straw or wood chips to conserve moisture and suppress weeds. Full sun (at least six to eight hours daily) produces the strongest fruit set. Growth rate is slow to moderate, with mature plants reaching 6–10 feet tall and 6–12 feet wide. Prune lightly after harvest to open the canopy and remove unproductive old canes. Irrigation during dry spells is essential since blueberries have shallow, fibrous roots. Avoid high-nitrogen synthetic fertilizers; use ammonium sulfate or acid-forming organic fertilizers in split applications.

USDA Hardiness Zone: 7-10
AHS Heat Zone: 7-10
Chill Hours: 200-400
Sun Requirements: Full Sun
Soil pH: 4.5-5.0
Soil Type: Acidic, sandy loam high in organic matter
Soil Drainage: Well-drained (excellent drainage required; intolerant of waterlogging)
Water Requirements: Medium (consistent, even moisture; shallow-rooted and intolerant of both drought and waterlogging)
Heat Tolerance: High; adapted to warm Southern climates with heat and humidity
Plant Spacing: 5-6 ft apart

Sharpblue forms an upright to spreading, vigorous Southern Highbush bush that reaches 6–10 feet tall and 6–12 feet wide at maturity. Foliage is glossy dark green and remains evergreen in Zones 9–10; in Zone 8 the plant may drop most leaves during cold snaps but leafs out again quickly in late winter. The semi-evergreen habit gives the landscape a year-round presence unusual among blueberries. Spring flowering is showy — small white bell-shaped blossoms appear on current-season wood before full leaf expansion. Growth rate is slow to moderate, so patience pays off: well-established plants produce abundantly for decades. Salt tolerance is low, so coastal plantings must use fresh-water irrigation. Deer find the twigs and shoots attractive; fencing or repellents are advisable where deer pressure is high. The plant supports bees, butterflies, songbirds, and small mammals, fitting naturally into edible-landscape and food-forest designs.

Mature Height: 6-10 ft tall
Mature Spread: 6-12 ft wide
Growth Habit: Upright, spreading shrub
Growth Rate: Slow to Moderate
Foliage Type: Evergreen (glossy dark green leaves; semi-evergreen in Zone 7 cold winters)
Food Forest Layer: Shrub
Permaculture Role: Edible fruit shrub; pollinator nectar source; wildlife food (berries) and habitat
Leaf Color: Green
Fall Foliage Color: Orange-red
Thorns?: No
Attracts Wildlife: Flowers attract bumblebees, native bees, and honey bees; ripe berries attract songbirds and small mammals
Life Span: 20-50 years

Sharpblue is partially self-fertile but sets significantly larger crops when cross-pollinated with at least one other low-chill Southern Highbush cultivar that flowers at the same time. Recommended companions include Misty Blueberry, Biloxi Blueberry, O’Neal Blueberry, Jewel Blueberry, and Emerald Blueberry. Sharpblue blooms in late winter to early spring in warm climates — often February through March in Florida and the Gulf Coast — so a companion that shares that early window is essential. Honeybees and native bumblebees are the primary pollinators; planting within 50–75 feet of companions maximizes bee movement between flowers.

Bloom Season: Very Early
Bloom Window: Mid Feb - Mid Apr
Pollination Requirements: Partially self-fertile; cross-pollination with another Southern Highbush variety significantly increases yield and fruit size
Pollination Mechanism: Insect-pollinated (buzz/sonication pollination by bumblebees and native bees; honey bees also forage)
Flower Color: White
Ploidy: Tetraploid (4x)

Sharpblue produces medium-sized, round berries with a mild, sweet-tart flavor and a good balance of sugar and brightness. Skin is a classic medium blue with a light silvery bloom; the dry stem scar makes for clean picking. Berries ripen in late spring — typically April through May in Florida and Zone 9, slightly later in cooler Zone 8 sites — extending the harvest window earlier than most Northern Highbush cultivars can manage. Texture is firm enough for fresh eating and packing, though not as firm as newer commercial SHB releases bred specifically for long-distance shipping. Home growers and local market farmers prize Sharpblue for fresh eating, jams, smoothies, and baked goods. Flavor is best when berries are allowed to fully ripen on the bush before picking — they sweeten noticeably in the final days of maturation.

Ripening Season: Very Early
Harvest Window: Mid May - Late Jun
Fruit Size: 0.5 inch (dime-sized; medium)
Flavor: Sweet, rich blueberry flavor; described as excellent quality for fresh eating
Fruit Color: Dark blue
Fruit Texture: Firm
Bearing Habit: Bears on previous year's wood; annual cropper
Years to Bear: 2-3 years
Yield: 15-20 per plant at maturity
Storage Life: 1-2 weeks refrigerated
Culinary Uses: Fresh eating, baking (muffins, pies, pancakes), jams, jellies, smoothies, freezing, drying

Sharpblue carries moderate susceptibility to Mummy Berry (Monilinia vaccinii-corymbosi), the most widespread blueberry disease in humid climates; raking and destroying fallen mummified fruit in late winter breaks the disease cycle effectively. Botryosphaeria Stem Blight (Botryosphaeria dothidea) is a concern on stressed plants — avoid drought stress and mechanical wounding, and remove blighted canes promptly. Anthracnose Fruit Rot (Colletotrichum acutatum) intensifies in wet, warm summers; thinning the canopy to improve air circulation is the first line of defense. Phytophthora Root Rot (Phytophthora cinnamomi) is the greatest cultural threat in poorly drained soils — raised beds and sandy well-drained media prevent most cases. Septoria Leaf Spot (Septoria albopunctata) is generally cosmetic but can cause early defoliation in wet seasons. On the pest side, Spotted Wing Drosophila and Blueberry Maggot are the primary fruit threats; fine mesh netting over ripening bushes is the most reliable organic control. Cranberry Fruitworm and Plum Curculio are secondary concerns managed with timely monitoring and removal of infested fruit.

Mummy Berry: Moderately Susceptible
Botryosphaeria Stem Blight: Resistant
Anthracnose Fruit Rot: Moderately Resistant
Phytophthora Root Rot: Moderately Susceptible
Septoria Leaf Spot: Moderately Susceptible
Spotted Wing Drosophila: Susceptible
Blueberry Maggot: Susceptible
Cranberry Fruitworm: Susceptible
Plum Curculio: Susceptible

• Soil pH Check: Test soil pH before planting and adjust to 4.5–5.0 with sulfur; retest annually — even one season above pH 5.5 causes yellowing that sets plants back.
• Deep Mulch: Mulch 4–6 inches deep with pine straw or wood chips and refresh each spring to hold moisture and maintain acidity.
• Companion Planting: Plant two different low-chill SHB companions within 50 feet to maximize cross-pollination and double your berry load.
• Late-Frost Protection: In colder-edge climates, protect blooms with frost cloth if late-winter freezes threaten after flowering has begun.

Our 365-Day Plant Guarantee: We ensure that our plants are delivered to you alive and healthy. If your plant does not survive its first year, you're eligible for store credit under these conditions:

1. Your location falls within the appropriate USDA hardiness zone for the plant variety (refer to our hardiness zone map).
2. You maintain the roots' moisture and plant within three days of delivery, following the instructions in our Planting Guide.

If you're concerned about your plant's health, please consult our guide, How to Tell if Your Tree is Dead or Dormant. Remember, our plants are shipped in a dormant state and may leaf out at different times based on their species. To check for plant vital