Riverdene Garden Centre
Frontenac Gris Grape
Frontenac Gris Grape
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Frontenac Gris Grape — Care & Culture Guide
Overview & Traits
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Frontenac Gris is a bud mutation / “gris” version of the Frontenac grape (the skin is lighter / grayish rather than deep red).
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It was introduced by the University of Minnesota in 2003.
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The grapes yield a peach-pink / coppery color and are useful for white or rosé wines, dessert styles, or fresh eating.
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It combines many of the cold tolerance and disease resistance attributes of the Frontenac family.
Hardiness, Vigor & Growth
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Extremely cold-hardy: tested to –35 °F (–37 °C) and shown to survive Minnesota winters.
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Vines are vigorous / semi-trailing and demand a sturdy support system.
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Moderately high vigor — management (pruning, training) is necessary to maintain balance.
Site & Soil
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Sunlight: Full sun is essential for fruit ripening and quality.
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Soil: Prefers well-drained soils (loamy, sandy). Avoid poorly drained or waterlogged soils.
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pH / Conditions: A moderately acid to neutral soil environment is beneficial; avoid extreme alkalinity or acidity. (General grape guidance)
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Spacing & Support: Each vine should have ~6 ft of horizontal space for growth and good airflow. It must be tied to a trellis / wire / arbor capable of supporting weight.
Planting & Establishment
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Timing: Plant early in spring (after last frost) to allow root establishment before winter.
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Root Care: If planting bare-root, soak roots before planting.
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First Pruning: After planting, roots should be pruned back tops to encourage root growth (cut cane to ~4-6 in).
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Mulching: Generally minimal near trunk to avoid cooling soil; keep mulch back from vine base.
Pruning, Training & Canopy Management
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Frontenac Gris supports both spur pruning and cane pruning.
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Maintain about 3 to 3.5 spurs per linear foot of cordon when spur pruning.
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Shoot thinning: Maintain 2 shoots per spur to prevent overcrowding.
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Renewal pruning: Replace older wood when necessary to maintain vine health.
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Bud / cluster load: Shoots may carry multiple clusters; manage load to balance vegetative growth and fruit quality.
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Fruit zone leaf removal & shoot thinning help expose fruit to sunlight, improving ripening and reducing disease pressure.
Pest & Disease Management
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Good disease resistance overall, but some vulnerabilities:
• Powdery mildew: moderate susceptibility.
• Leaf phylloxera: moderate susceptibility.
• Black rot: low to moderate susceptibility.
• Very low susceptibility to downy mildew, bunch rots (Botrytis). -
Preventive strategies:
• Fungicide program, especially at bloom, helps manage disease.
• Remove diseased wood, maintain airflow, avoid overhead irrigation
• Monitor regularly and remove weak or infected canes
Harvesting & Ripening
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Frontenac Gris typically ripens in early September (in regions like Minnesota) but may be delayed or extended depending on climate.
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Sugar levels (°Brix) target ~ 23-26 °Brix for harvest; acidity and pH should also be monitored.
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Harvest later if desired for sweeter or dessert styles, but risk of dropping acidity or disease.
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Clip clusters carefully, discard damaged or discolored berries.