Cowart Muscadine Grape

Cowart was selected from the cross Higgins x Ga. 28, made in 1960 at the University of Georgia, and released in 1968 by B.O. Fry of the Georgia Agricultural Experiment Station. The Higgins parent, released in 1955, was chosen specifically for its documented ability to transmit large berry size to progeny — a trait Fry exploited in multiple cultivars including Fry, Jumbo, and Cowart. Of those releases, Cowart was the first UGA cultivar to carry perfect (bisexual) flowers, a landmark achievement that eliminated the requirement for a separate male or pistillate-flowered pollinizer in commercial and home plantings. This self-fertile trait, combined with dark skin color, mid-to-late-season ripening, and reliable cropping under the high heat and humidity of the Deep South, drove Cowart’s adoption as one of the most widely planted commercial muscadines in the Southeast through the 1970s and 1980s. In many large plantings it served as the pollinizer for the bronze cultivar Fry.

Cowart's native range — the humid coastal plain from Virginia to Texas — tells you what it needs: high heat accumulation, adequate moisture during fruit development, and well-drained soil. A soil pH of 5.8 to 6.5 keeps iron and manganese available without toxicity, and sandy or loamy profiles drain quickly enough to prevent the root rot that plagues muscadines in compacted clay. Full sun across the entire vine canopy is critical because Cowart sets fruit on current-season growth from last year's spurs; shaded interior shoots contribute little to yield. Water management matters most from fruit set through harvest — roughly six to eight weeks — when moisture stress tightens berry size and drops sugar below its documented ~17% level. Once established, the vine tolerates short dry spells but performs best with about one inch of water per week during that fruit-development window. Low chill of just 100–200 hours makes Cowart reliable across mild-winter coastal areas and lower elevations in zones 7–9, with no risk of premature bud break even in warm-winter years.

USDA Hardiness Zone: 7-9
AHS Heat Zone: 6-11
Chill Hours: 150-350
Sun Requirements: Full Sun
Soil pH: 5.8-6.5
Soil Type: Well-drained loam or sandy loam; tolerates clay with good drainage
Soil Drainage: Well-drained; does not tolerate poor drainage or waterlogged soils
Water Requirements: Medium; drought tolerant once established but benefits from regular moisture during fruit set
Drought Tolerance: Moderate; established vines tolerate short dry periods but fruit quality suffers without adequate moisture
Heat Tolerance: High; native to the humid Southeast and thrives in high summer heat
Plant Spacing: 15-20 ft apart
Container Suitability: Not suitable; vigorous vine requires ground planting with trellis support
How to Prune: Prune annually during dormancy (mid-January or later). Cut lateral shoots back to 2-4 buds. Establish spurs spaced approximately 6 inches apart on permanent cordons.

Cowart is a vigorous deciduous vine that pushes 15 to 20 feet of extension if unchecked — an asset that requires annual management. Rapid growth means the permanent cordon framework can be established within two seasons, getting the vine into production quickly. The root system is deep and fibrous, anchoring the plant well and allowing it to access moisture from lower soil horizons, but this same architecture makes it a known host for grape root borer larvae that tunnel into larger roots near the crown. Leaves run medium to dark green through the season with no notable fall color. Fruiting occurs on current-year lateral shoots, so the pruning objective is maintaining well-spaced spurs at roughly six-inch intervals along each cordon rather than thinning to long canes. Without consistent annual pruning, the canopy thickens rapidly, cutting airflow — the primary driver of fungal pressure in humid climates — and shifting growth away from fruit production.

Mature Height: 10-20 ft tall
Mature Spread: 15-20 ft wide
Growth Habit: Vigorous climbing/trailing deciduous vine; requires trellis, arbor, or fence for support
Growth Rate: Fast
Foliage Type: Deciduous
Food Forest Layer: Canopy, Vine
Leaf Color: Medium to dark green
Thorns?: No
Attracts Wildlife: Birds, deer, foxes, raccoons, opossums
Life Span: productive for 20-40+ years

Cowart produces perfect flowers — that is, each bloom carries both male stamens and a functional pistil — so the vine sets fruit from its own pollen without any companion planting. Bloom opens from May into June in temperate climates, coinciding with warm-season insect flight and wind dispersal. Although Cowart is self-productive, its perfect-flower status gives it a secondary role as a pollinizer for female-only muscadines planted in the same block. Varieties like Noble Muscadine Grape and Scuppernong Grape carry only pistillate (female) flowers and produce no pollen; interplanting one Cowart vine per three to five female vines ensures those varieties fruit reliably. For growers focused on Cowart's own yield, pairing it with another perfect-flowered cultivar like Carlos Muscadine Grape has been shown in university trials to increase berry set modestly beyond self-pollination alone.

Bloom Season: Very Late
Bloom Window: Mid May - Mid Jun
Pollination Requirements: Self-fertile (perfect-flowered); does not require a pollinator, but planting with other varieties can increase yield
Pollination Mechanism: Wind and insect pollination
Flower Color: Greenish-white
Ploidy: Diploid (2n = 40)

Berries ripen dark blue-black with a thick, tough but edible skin that holds up well to the humidity of harvest season. Individual diameter runs about 1 inch with a weight of 7.5 to 10 grams — mid-sized for muscadines — and the firm, juicy pulp delivers the characteristic musky, complex muscadine flavor at documented sugar levels near 17% by weight. Acidity is moderate; the profile layers sweet musk over a slightly earthy undertone that distinguishes it clearly from bunch grape types. Berries ripen unevenly over a three- to four-week window rather than all at once, distributing fresh harvest across the season but requiring two to three picking passes to capture fruit at peak ripeness. Refrigerated shelf life runs one to two weeks — the moist detachment scar creates an entry point for spoilage — so plan to process or eat fresh promptly. Cowart's flavor intensity and high sugar make it a natural for juice, wine, jelly, and preserves; many growers also squeeze the pulp from the skin for fresh eating.

Ripening Season: Mid
Harvest Window: Late Aug - Mid Sep
Fruit Size: 1 inch
Fruit Weight: 7.5-10 g
Flavor: Sweet, musky muscadine flavor with rich, complex character; approximately 17% sugar
Fruit Color: Black (dark blue-black)
Fruit Texture: Firm, juicy pulp
Fruit Skin: Thick, tough skin; edible
Bearing Habit: Annual bearer; berries ripen unevenly over an extended season
Years to Bear: 2-4 years
Yield: 60+ per vine
Storage Life: 1-2 weeks refrigerated; berries do not hold as long as bunch grapes due to moist scar
Culinary Uses: Fresh eating, juice, jelly, jam, preserves, wine

Bitter rot (Greeneria uvicola) is Cowart's primary disease liability. The pathogen thrives in warm, humid conditions, and susceptible vines can lose a significant crop share in wet summers. Organic management centers on canopy structure: annual dormant pruning combined with summer hedging reduces leaf wetness duration enough to limit spore germination. Prompt removal of infected berries and fallen fruit cuts inoculum buildup. OMRI-listed copper fungicides at early bloom and fruit set provide a backstop in high-pressure seasons. Ripe rot (Glomerella cingulata) poses a moderate secondary risk on fruit held past peak ripeness; timely harvest is the primary control. Cowart is moderately resistant to angular leaf spot (Mycosphaerella angulata) and black rot (Guignardia bidwellii f. muscadinii) — good airflow and basic sanitation are normally sufficient for both. Powdery mildew (Uncinula necator) is a genuine strength; the variety rarely needs targeted intervention. Grape root borer (Vitacea polistiformis) is the most structurally serious pest: larvae tunnel into the root crown before symptoms appear. Pheromone-trap monitoring from late June and soil mounding to expose egg masses are the main organic strategies. Japanese beetle (Popillia japonica), grape leafhopper (Erythroneura spp.), and grape berry moth (Endopiza viteana) cause moderate injury; kaolin clay, row covers on young vines, and pheromone disruption manage all three without synthetic inputs.

Bitter Rot: Susceptible
Angular Leaf Spot: Moderately Resistant
Black Rot: Moderately Resistant
Ripe Rot: Moderately Susceptible
Powdery Mildew: Resistant
Grape Root Borer: Susceptible
Japanese Beetle: Moderately Susceptible
Grape Leafhopper: Moderately Susceptible
Grape Berry Moth: Moderately Susceptible

• Bitter Rot Pressure Window: The highest risk occurs during the two to three weeks before harvest when berries are softening; keep the canopy open, scout weekly, and remove infected clusters on the spot rather than dropping them under the vine.
• Root Borer Monitoring: Starting in late June, place pheromone traps near the root zone to detect adult Grape Root Borer moths; mound soil around the vine base in early summer and check for egg masses, as disrupting the mound exposes eggs to desiccation and predation.
• Prune Hard Every Dormant Season: Cut lateral shoots back to two to four buds each winter; skipping even one year allows the spur system to elongate and create conditions that amplify every fungal disease on Cowart's susceptibility list.
• Harvest in Passes, Not One Sweep: Berries ripen over three to four weeks; plan two to three picking passes per vine to capture peak quality and minimize overripe fruit fermenting on the ground.

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