Entire healthy mature calendula plant in a real garden bed, showing growth habit and scale.Primary identification image. 30–60 cm tall, 30–45 cm wide at maturity.
3. FloweringOrange or yellow daisies from 6–8 weeks.
4. DeadheadRemove spent blooms; or leave some to self-seed.
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 1 weeks before to 2 weeks after last frost; direct sow 2 weeks before to 3 weeks after last frost; 45–60 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.
Plant
JanFebMarAprMayJunJulAugSepOctNovDec
CalendulaCalendula officinalis
Text version of the planting timeline
Plant
Start indoors
Direct sow
Autumn sow
Transplant
Tend
Harvest
Calendula
Feb 22–Mar 8 (estimate)
Mar 22–Apr 26 (estimate)
Sep 10–Sep 24 (estimate)
Mar 29–Apr 19 (estimate)
Apr 26–May 6 (estimate)
May 6–Oct 15 (estimate)
Start indoorsDirect sowTransplantTendHarvestStriped bars are regional estimates; solid bars are dates you confirmed.
Start seeds indoors: Feb 22 – Mar 8
Direct sow: Mar 22 – Apr 26
Transplant outdoors: Mar 29 – Apr 19
Tend and monitor: Apr 26 – May 6
Harvest: May 6 – Oct 15
Autumn sowing: Sep 10 – Sep 24
Spacing & support
In-row 25–30 cm; rows 30–45 cm. Planner footprint: 1 cell of 30 cm.
Side-profile diagram of mature calendula: canopy 30–60 cm tall, 30–45 cm wide, medium root zone, support and harvest-access envelope.
Soil & water
Soil
Any well-drained soil
pH
6–7
Fertility
low
Water
Moderate; drought-tolerant.
Frost
hardy; tolerates frost
Support & training
No support structure needed.
Calendula mid-season before harvest, showing branching, vining, rosette or upright habit and space occupied.
Harvest signs
Pick flowers fully open for petals
Deadhead to prolong bloom
Calendula at harvest readiness, showing the visual cues: pick flowers fully open for petals; deadhead to prolong bloom.
Calendula (pot marigold, not to be confused with Tagetes marigold) is sown directly from a few weeks before the last frost, or in autumn for early flowers, and blooms within 6–8 weeks. It tolerates frost and poor soil and self-seeds readily.
Calendula seed beside a ruler or coin for scale.
Calendula seedling at cotyledon and first-true-leaf stage, in soil, distinguishable from common weeds.
Calendula mid-season before harvest, showing branching, vining, rosette or upright habit and space occupied.
Single-flowered cultivars offer accessible pollen and nectar to hoverflies and bees; doubles less so. Aphids often colonise the stems, which makes it a host rather than a repellent. Powdery mildew arrives in late summer.
Two or more mature calendula plants with a tape measure showing in-row spacing (25–30 cm).
Calendula flower detail or bolting stage.
Immature petals of calendula developing on the plant.
Edible parts and safety
Edible: petals.
Hands or tool harvesting calendula correctly (cut, pull, twist or pick) without damaging the plant.
Pests and diseases
Common pests: aphids, slugs. Common diseases: powdery mildew. These vary by region; a photograph is an example, not a diagnosis. See the pest and disease guides and your local extension service.
aphids on calendula, with a wider damage-context view.
Timeline
Season timeline for calendula: sowing, transplanting, flowering, harvest and bed occupancy aligned to frost dates.Text alternative: Start seeds indoors Feb 22–Mar 8; Direct sow Mar 22–Apr 26; Transplant outdoors Mar 29–Apr 19; Tend and monitor Apr 26–May 6; Harvest May 6–Oct 15; Autumn sowing Sep 10–Sep 24.
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
Spacing & support
Soil & water
Support & training
Harvest signs
Common problems
Container growing
Companion overview
Crop rotation
Sources, reviewer & update
