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Entire healthy mature swiss chard plant in a real garden bed, showing growth habit and scale.Primary identification image. 30–60 cm tall, 30–45 cm wide at maturity.

Swiss chard

Beta vulgaris subsp. vulgaris (Cicla Group) L.

Also called: Chard, Silverbeet, Leaf beet

Family
Amaranthaceae
Season
Cool-season biennial grown as an annual
Best grown in
Portland, Oregon

The most forgiving leaf crop: sown in spring, picked for months, tolerant of heat and light frost.

Safety: High in oxalates; fine in normal amounts.

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Life cycle & growth stages

  1. 1. Seed clusterSow 2 cm deep; clusters give several seedlings.
  2. 2. SeedlingEmerges in 7–14 days.
  3. 3. ThinningThin to 20–30 cm.
  4. 4. Mid-growthUpright glossy leaves with coloured stalks.
  5. 5. Harvest readyOuter leaves 20 cm.
  6. 6. HarvestCut outer stalks repeatedly.
  7. 7. OverwinteringSurvives light frost; bolts the next spring.

Growth stages are ordered chronologically; timing varies with cultivar, temperature, light and care.

Planting calendar for Portland, Oregon

Start indoors 4–6 weeks before last frost; transplant 2 weeks before to 2 weeks after last frost; direct sow 2 weeks before to 6 weeks after last frost; 50–60 days to maturity from sowing. Windows are derived from the region's average frost dates (last Apr 5, first Nov 5) and are estimates until you confirm your own dates in the calendar.

Swiss chardBeta vulgaris subsp. vulgaris (Cicla Group)
PlantStart indoorsDirect sowAutumn sowTransplantTendHarvest
Swiss chardFeb 22–Mar 8 (estimate)Mar 22–May 17 (estimate)Aug 27–Sep 10 (estimate)Mar 22–Apr 19 (estimate)—May 11–Nov 5 (estimate)
  • Start seeds indoors: Feb 22 – Mar 8
  • Transplant outdoors: Mar 22 – Apr 19
  • Direct sow: Mar 22 – May 17
  • Harvest: May 11 – Nov 5
  • Autumn sowing: Aug 27 – Sep 10

Spacing & support

In-row 20–30 cm; rows 45–45 cm. Planner footprint: 1 cell of 30 cm, 2 plants per cell.

Side-profile diagram of mature swiss chard: canopy 30–60 cm tall, 30–45 cm wide, medium root zone, support and harvest-access envelope.

Soil & water

Soil
Fertile, moist loam
pH
6–7
Fertility
moderate
Water
Regular water for tender leaves.
Frost
hardy; tolerates frost

Support & training

No support structure needed.

Swiss chard mid-season before harvest, showing branching, vining, rosette or upright habit and space occupied.

Harvest signs

  • Outer leaves 20–25 cm
  • Cut at the base; leave the centre
Swiss chard at harvest readiness, showing the visual cues: outer leaves 20–25 cm; cut at the base; leave the centre.

Common problems

Pests: beet leaf miner, slugs, aphids

Diseases: Cercospora leaf spot, downy mildew

Appearance alone is not a diagnosis; confirm with a regional extension guide.

Side-by-side: healthy swiss chard leaf or fruit and an example of Cercospora leaf spot.

Container growing

  • Minimum 10 L (20 cm deep)
  • Use quality potting mix and water more frequently
Mature swiss chard in a correctly sized container (10 L or more) with drainage visible.

Companion overview

1 reviewed relationship record (evidence: low).

Supported or conditional

None reviewed

Avoid or separate

None with evidence

1 popular pairing reviewed with no verified relationship.

Full companion profile

Crop rotation

Avoid planting swiss chard or other beet family crops in the same spot for 2 years. Rotation is about previous seasons, not about live neighbours.

Year 1Year 2Year 3AmaranthaceaeOther familyOther familyback after 2+ years

Shared risks in Amaranthaceae: leaf miner (Pegomya), Cercospora leaf spot, downy mildew.

Crop rotation hub

Sources, reviewer & update

Sources

Reviewer: Garden Planner editorial team (pending independent horticultural review)

Last reviewed: August 15, 2026 · version 1

Found an error or have feedback? Let us know.

Growing swiss chard

Chard is sown directly or transplanted around the last frost and picked from 50–60 days for the rest of the season; it tolerates summer heat better than spinach or lettuce and stands light frost in autumn. Cut outer stalks at the base and the plant keeps producing.

Swiss chard seed beside a ruler or coin for scale.
Swiss chard seedling at cotyledon and first-true-leaf stage, in soil, distinguishable from common weeds.
Swiss chard mid-season before harvest, showing branching, vining, rosette or upright habit and space occupied.

Chard is the same species as beet and shares leaf miners and Cercospora leaf spot; rotate them together. Plants reach 30–60 cm and need 20–30 cm spacing.

Two or more mature swiss chard plants with a tape measure showing in-row spacing (20–30 cm).
Swiss chard flower detail or bolting stage.
Immature leaves of swiss chard developing on the plant.

Edible parts and safety

Edible: leaves, stalks. High in oxalates; fine in normal amounts.

Hands or tool harvesting swiss chard correctly (cut, pull, twist or pick) without damaging the plant.

Pests and diseases

Common pests: beet leaf miner, slugs, aphids. Common diseases: Cercospora leaf spot, downy mildew. These vary by region; a photograph is an example, not a diagnosis. See the pest and disease guides and your local extension service.

beet leaf miner on swiss chard, with a wider damage-context view.

Timeline

Season timeline for swiss chard: sowing, transplanting, flowering, harvest and bed occupancy aligned to frost dates.Text alternative: Start seeds indoors Feb 22–Mar 8; Transplant outdoors Mar 22–Apr 19; Direct sow Mar 22–May 17; Harvest May 11–Nov 5; Autumn sowing Aug 27–Sep 10.

Related plants

See also: Amaranthaceae family page · crop rotation · regional calendar · guides

Our Methodology & Sources

We synthesize peer-reviewed research, university extension publications, and trusted horticulture resources. Our evidence levels help you understand how strong the science is behind the guidance.

Evidence tiers

Supported evidenceConsistent results from multiple robust studies
Traditional claimHistorical use reported, limited scientific support
Context dependentMixed or variable results across conditions
No verified relationshipNo reliable evidence identified

Primary source types

  • Peer-reviewed journal articles
  • University extension publications
  • Government & research institute reports
  • Systematic reviews & meta-analyses

Last updated

August 24, 2026

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