Riverdene Garden Centre

Frontenac Gris Grape

Frontenac Gris Grape

Regular price $25.00 CAD
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Frontenac Gris Grape — Care & Culture Guide

Overview & Traits

  • Frontenac Gris is a bud mutation / “gris” version of the Frontenac grape (the skin is lighter / grayish rather than deep red). 

  • It was introduced by the University of Minnesota in 2003. 

  • The grapes yield a peach-pink / coppery color and are useful for white or rosé wines, dessert styles, or fresh eating. 

  • It combines many of the cold tolerance and disease resistance attributes of the Frontenac family. 


Hardiness, Vigor & Growth

  • Extremely cold-hardy: tested to –35 °F (–37 °C) and shown to survive Minnesota winters. 

  • Vines are vigorous / semi-trailing and demand a sturdy support system.

  • Moderately high vigor — management (pruning, training) is necessary to maintain balance. 


Site & Soil

  • Sunlight: Full sun is essential for fruit ripening and quality. 

  • Soil: Prefers well-drained soils (loamy, sandy). Avoid poorly drained or waterlogged soils. 

  • pH / Conditions: A moderately acid to neutral soil environment is beneficial; avoid extreme alkalinity or acidity. (General grape guidance)

  • 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

  • Timing: Plant early in spring (after last frost) to allow root establishment before winter. 

  • Root Care: If planting bare-root, soak roots before planting. 

  • First Pruning: After planting, roots should be pruned back tops to encourage root growth (cut cane to ~4-6 in). 

  • Mulching: Generally minimal near trunk to avoid cooling soil; keep mulch back from vine base. 


Pruning, Training & Canopy Management

  • Frontenac Gris supports both spur pruning and cane pruning

  • Maintain about 3 to 3.5 spurs per linear foot of cordon when spur pruning. 

  • Shoot thinning: Maintain 2 shoots per spur to prevent overcrowding. 

  • Renewal pruning: Replace older wood when necessary to maintain vine health. 

  • Bud / cluster load: Shoots may carry multiple clusters; manage load to balance vegetative growth and fruit quality. 

  • Fruit zone leaf removal & shoot thinning help expose fruit to sunlight, improving ripening and reducing disease pressure. 


Pest & Disease Management

  • 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

  • Frontenac Gris typically ripens in early September (in regions like Minnesota) but may be delayed or extended depending on climate. 

  • Sugar levels (°Brix) target ~ 23-26 °Brix for harvest; acidity and pH should also be monitored. 

  • Harvest later if desired for sweeter or dessert styles, but risk of dropping acidity or disease. 

  • Clip clusters carefully, discard damaged or discolored berries. 

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