Growli
Get the app

Plant care

Echinacea 'Magnus' (Magnus purple coneflower) care

Echinacea purpurea 'Magnus'

Also called Magnus purple coneflower.

RHS H7USDA 3-8Pet-safeIndoor 75-90 cm tall and 45-60 cm wide.

Watering rhythm

Direct sun (at least 4-6 hours)

When the top 3-5 cm of soil is dry, about weekly until established

Jump to schedule→Get smart reminders in the app

Light

Direct sun (at least 4-6 hours)

Soil

Average, well-draining loam

Humidity

40-60%

Temp

-34 to 30°C

Pet safety

Pet-safe

Mature size

75-90 cm tall and 45-60 cm wide.

Care at a glance

Light

Most houseplants will scorch where echinacea 'magnus' thrives. Give it the windowsill you'd otherwise leave empty because everything else burned there. Full sun produces the strongest stems and heaviest flowering. It tolerates light afternoon shade but tends to stretch and flower less in shadier spots. Aim for at least six hours of direct sun. A plant moved abruptly from low light to direct sun bleaches in 48 hours — always acclimatise over a week.

Watering

Aim for when the top 3-5 cm of soil is dry, about weekly until established for echinacea 'magnus', but treat that as a starting point rather than a rule. A south-facing summer windowsill will dry the pot twice as fast as a north-facing winter room. Lift the pot; if it feels noticeably lighter than it did wet, water it. Water regularly through the first growing season to build deep roots. Once established it is markedly drought-tolerant and needs watering only in extended dry weather. Avoid overwatering and wet soil, which invite rot.

Soil and pot

Echinacea 'Magnus' grows best in average, well-draining loam. Prefers moderately fertile, well-draining soil and tolerates poor and rocky ground. Neutral to slightly alkaline pH suits it. Sharp drainage, especially in winter, is the key to longevity, as it dislikes heavy wet soils. A pot with a working drainage hole is non-negotiable for this species — even free-draining mix will turn soggy in a closed planter. If you love the look of a decorative pot without a hole, use it as a cachepot around an inner nursery pot you can lift out to water.

Humidity and temperature

Echinacea 'Magnus' sits happiest at around 40-60% humidity and -34 to 30°C (-30 to 86°F). A hardy prairie perennial indifferent to humidity. Good air circulation matters more than humidity, as crowded, damp conditions encourage powdery mildew and aster yellows. If you keep the room above year-round and avoid placing the plant near a cold draught, a hot radiator, or an air-conditioning vent, you have already handled the two biggest indoor stressors.

Fertilising

Feed echinacea 'magnus' sparingly. Light feeder; an annual spring application of compost or a balanced slow-release fertiliser is sufficient. Avoid rich, high-nitrogen feeding, which causes floppy growth and fewer flowers. In reasonable soil it performs well with no extra feeding. Skip fertiliser entirely on a stressed, recently-repotted, or actively wilting plant — fertiliser salts make damage worse, not better. Wait for a round of healthy new growth before resuming a feeding rhythm.

Common problems

Below are the issues we see most often on echinacea 'magnus' in the Growli community. Each is annotated with the most common cause so you know where to start.

  • Powdery mildew — White powdery coating appears on crowded plants in humid weather. Space for airflow, avoid overhead watering and remove affected leaves.
  • Aster yellows — This phytoplasma disease causes distorted, greenish deformed flowers. There is no cure; remove and destroy affected plants and control leafhoppers that spread it.
  • Crown and root rot — Heavy, wet winter soil rots the crown and shortens the plant's life. Plant in sharply drained soil and avoid waterlogging.
  • Floppy stems — Over-rich soil or too much shade weakens stems. Grow in full sun and lean soil; divide congested clumps every three to four years to maintain vigour.

Propagation

Propagate by division of established clumps in spring or autumn every few years, or by root cuttings in winter. Seed-grown plants of cultivars may not come fully true to type, so division is preferred to keep 'Magnus' characteristics; it also self-sows lightly. Propagation is the cheapest, most satisfying way to expand a collection — and it doubles as insurance against losing a mature plant to an accident. Take a backup cutting once the parent is established and healthy.

Toxicity to pets

Echinacea 'Magnus' is pet-safe. The ASPCA lists Echinacea as non-toxic to cats and dogs, with no recognised toxic principle. As with any plant, nibbling foliage may cause mild, transient gastrointestinal upset. If you keep cats, dogs, or curious children in the house, weigh placement carefully — a high shelf or a hanging planter is enough for casual safety. For severe ingestion incidents, call your local vet and the ASPCA Animal Poison Control Center (in the US, 888-426-4435 in the US, or Animal PoisonLine on 01202 509 000 in the UK).

Pet-safety status is sourced from the ASPCA Toxic and Non-Toxic Plant List, which catalogues the most-asked-about plants for cats, dogs, and horses.

Echinacea 'Magnus' care — frequently asked questions

What is the common name for Echinacea purpurea 'Magnus'?

Echinacea purpurea 'Magnus' is most commonly called Echinacea 'Magnus', but it is also known as Magnus purple coneflower. The names refer to the same species, so care instructions for Echinacea 'Magnus' apply identically to anything sold as Magnus purple coneflower.

How much light does echinacea 'magnus' need?

Echinacea 'Magnus' grows best in direct sun (at least 4-6 hours). Full sun produces the strongest stems and heaviest flowering. It tolerates light afternoon shade but tends to stretch and flower less in shadier spots. Aim for at least six hours of direct sun.

How often should I water echinacea 'magnus'?

Water echinacea 'magnus' when the top 3-5 cm of soil is dry, about weekly until established. Water regularly through the first growing season to build deep roots. Once established it is markedly drought-tolerant and needs watering only in extended dry weather. Avoid overwatering and wet soil, which invite rot. The finger-test (or lifting the pot to feel its weight) beats a fixed weekly calendar because pot size, light, and season all change how fast the soil dries.

Is echinacea 'magnus' toxic to cats and dogs?

Echinacea 'Magnus' is pet-safe. The ASPCA lists Echinacea as non-toxic to cats and dogs, with no recognised toxic principle. As with any plant, nibbling foliage may cause mild, transient gastrointestinal upset.

What USDA hardiness zone does echinacea 'magnus' grow in?

Echinacea 'Magnus' is rated for USDA zone 3-8 and RHS hardiness H7. Outside that range, grow it as a container plant that overwinters indoors before the first hard frost.

Echinacea 'Magnus' deep-dive guides

Every aspect of echinacea 'magnus' care, each with its own calibrated guide:

Featured in these plant shortlists

Echinacea 'Magnus' qualifies for 10 curated Growli shortlists — each one filtered objectively from our structured plant-care library, so the selection is consistent and checkable:

Related guides

Echinacea 'Magnus' is also commonly called Magnus purple coneflower.