Swiss Chard Mastery: Varieties, Succession Planting & Season Extension

Beyond the Basics: Intermediate Swiss Chard Growing

You've grown Swiss chard successfully and experienced its easy-going nature and stunning colors. Now it's time to optimize production with strategic variety selection, succession planting, and season extension techniques that can provide fresh chard nearly year-round in most climates.

Deep Dive into Swiss Chard Varieties

White-Stemmed Varieties

Fordhook Giant

• Industry standard white chard
• Thick, fleshy stems 2.5 inches wide
• Dark green, heavily crinkled leaves
• Plants reach 24-28 inches tall
• Tolerates poor soil and frost
• Days to maturity: 50-55
• Best for: Reliability, cooking

Lucullus

• Named for Roman gastronome
• Pale green to white stems
• Large, heavily savoyed leaves
• Plants reach 20 inches tall
• Mild, tender flavor
• Days to maturity: 50-55
• Best for: Raw eating, mild taste

White Silver

• Pure white stems
• Very thick, celery-like stalks
• Smooth to slightly savoyed leaves
• Days to maturity: 55
• Best for: Stem harvest, visual contrast

Red-Stemmed Varieties

Ruby Red (Rhubarb Chard)

• Deep crimson stems and veins
• Dark green to bronze leaves
• Striking visual appeal
• Slightly earthy flavor
• Days to maturity: 55-60
• Best for: Color, ornamental edibles

Magenta Sunset

• Bright magenta-pink stems
• Green leaves with pink veins
• Very tender
• Days to maturity: 55
• Best for: Baby leaf, visual appeal

Burgundy

• Deep burgundy-red throughout
• Darker leaves than Ruby Red
• Compact growth habit
• Days to maturity: 55-60
• Best for: Containers, dramatic color

Yellow/Orange-Stemmed Varieties

Golden

• Bright golden-yellow stems
• Medium green leaves
• Mild, slightly sweet flavor
• Less cold-hardy than red types
• Days to maturity: 55-60
• Best for: Color variety, mild taste

Orange Fantasia

• Vibrant orange stems
• Green leaves with orange veins
• Eye-catching in the garden
• Days to maturity: 55
• Best for: Rainbow mixes, visual impact

Multi-Colored Varieties

Bright Lights

• All-America Selections winner
• Mix of red, yellow, orange, pink, white stems
• Some plants have striped stems
• Consistent flavor across colors
• Days to maturity: 55-60
• Best for: Maximum color variety

Rainbow Mix

• Blend of Ruby Red, Golden, Magenta, White Cloud
• Similar to Bright Lights
• May have different variety proportions
• Days to maturity: 55
• Best for: Cut flower gardens, farmers markets

Peppermint

• Green leaves with pink-and-white striped stems
• Unique candy-cane appearance
• Bolt-resistant
• Good for containers
• Days to maturity: 60
• Best for: Novelty, extended harvest

Spinach Beet (Perpetual Spinach)

Perpetual Spinach

• Small, smooth leaves (not typical chard)
• Thin green stems
• Tastes like mild spinach
• Very bolt-resistant
• Days to maturity: 50
• Best for: Spinach substitute, long harvest

Succession Planting Strategy

The Succession Planting Calendar

Continuous Harvest Plan

Goal: Fresh Swiss chard year-round

1. Plant every 4-6 weeks from early spring through late summer
2. Overlap harvests by maintaining multiple plantings
3. Transition varieties based on season:
   • Spring: Any variety
   • Summer: Heat-tolerant varieties
   • Fall/Winter: Cold-hardy white and red types

Example Schedule (Zone 6)

Season Extension Techniques

Cold Frame Production

Swiss chard is ideal for cold frame growing due to its frost tolerance:

Design specifications:

• South-facing orientation
• Back wall 12-18 inches, front wall 6-8 inches
• Transparent lid (glass or polycarbonate)
• Ventilation capability

Management:

• Open lid when interior exceeds 70°F (21°C)
• Close before sunset to trap heat
• Water sparingly in cold months
• Remove snow from lid promptly

Temperature protection:

• Swiss chard survives to 15°F (-9°C) unprotected
• Cold frame adds 10-20°F protection
• Can harvest through winter in zones 5-6+

Low Tunnel System

Materials:

• Wire hoops or PVC (5-7 feet long)
• Row cover fabric (various weights)
• Sandbags or soil for anchoring

Cover selection:

• Light (0.5 oz): Pest protection only
• Medium (1.25 oz): 4-6°F frost protection
• Heavy (2.0 oz): 6-8°F protection, winter growing

Benefits:

• Extends season 4-6 weeks each direction
• Protects from hard freezes
• Reduces pest pressure

Overwintering Swiss Chard

In zones 6 and warmer, chard can overwinter:

Site preparation:

• Choose protected location
• South-facing, near building if possible
• Well-drained soil (prevents root rot)

Winter protection:

• Apply 4-6 inches mulch after hard freeze
• Cover with row cover or cold frame
• Remove mulch gradually in spring

Spring regrowth:

• Plants resume growth above 40°F
• Harvest quickly before bolting
• Second-year plants will flower

Pro Tip: Overwintered chard produces extremely early spring harvests—often weeks before spring-planted crops are ready.

Integrated Pest Management (IPM)

Understanding the Pest Calendar

Cercospora Leaf Spot Management

This is the most serious disease of Swiss chard:

Identification:

• Small circular spots (initially)
• Pale brown/gray centers with red margins
• Spots expand and coalesce
• Severe defoliation possible

Favorable conditions:

• High humidity (>90%)
• Temperatures above 75°F
• Rain splash spreads spores
• Wet foliage

Cultural controls:

• 2-3 year crop rotation (away from beets, spinach)
• Adequate plant spacing for air circulation
• Drip irrigation (avoid wetting foliage)
• Remove and destroy infected leaves
• Clean up debris after harvest

Fungicide options:

• Copper-based products (organic)
• Chlorothalonil (conventional)
• Apply preventatively before disease pressure

Leaf Miner Control

Biology:

• Adult flies lay eggs on leaf undersides
• Larvae tunnel between leaf surfaces
• Multiple generations per year

Controls:

• Floating row covers (most effective)
• Remove and destroy affected leaves
• Spinosad sprays for severe infestations
• Encourage parasitic wasps

Biological Control Resources

Beneficial insects:

• Lady beetles for aphids
• Lacewings for various soft-bodied insects
• Parasitic wasps for leaf miners

Attracting beneficials:

• Plant alyssum, yarrow, dill nearby
• Avoid broad-spectrum pesticides
• Provide water sources

Optimizing Harvest Quality

Timing Harvest for Best Quality

Factors affecting quality:

• Leaf size: Smaller = more tender, larger = more productive
• Time of day: Morning harvest has highest water content
• Temperature: Cool weather improves flavor
• Plant age: Younger plants tend to be more tender

Optimal harvest timing:

• Baby leaves: 3-4 inches (salads, garnishes)
• Medium leaves: 6-8 inches (versatile)
• Full-size: 10-12 inches (cooking)

Post-Harvest Handling

Immediate handling:

• Harvest into clean containers
• Move to shade immediately
• Cool as quickly as possible
• Target 32-36°F (0-2°C)

Storage:

• Temperature: 32-36°F (0-2°C)
• Humidity: 95-98%
• Shelf life: 7-14 days (optimal conditions)
• Don't wash until ready to use

Quality indicators:

• Crisp, turgid leaves
• Bright stem color
• No yellowing or wilting
• Clean cut ends

Variety Trial Recommendations

Taste Test Categories

Mildest flavor:

1. Lucullus
2. Golden
3. Perpetual Spinach

Best for raw eating:

1. Perpetual Spinach (baby leaves)
2. Bright Lights (young leaves)
3. Lucullus

Best for cooking:

1. Fordhook Giant
2. Ruby Red
3. Rainbow Mix

Most ornamental:

1. Bright Lights
2. Peppermint
3. Ruby Red

Cold Hardiness Ranking

Quick Reference: Intermediate Techniques

Next Level: Advanced Guide

The Advanced guide covers:

• Commercial production systems
• Intensive planting and harvest techniques
• Advanced disease management protocols
• Post-harvest handling for markets
• Fertigation and irrigation optimization
• Quality metrics and grading