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Plant care

Hosta 'August Moon' (August Moon Hosta) care

Hosta 'August Moon'

Also called August Moon Hosta, August Moon Plantain Lily.

RHS H7USDA 3-9Toxic to petsIndoor 55-65 cm tall

Watering rhythm

6-7days

When the top 3 cm of soil is dry, roughly every 6-7 days in summer

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Light

Medium indirect light (a couple of metres from a window)

Soil

Fertile, humus-rich, well-draining loam

Humidity

45-65%

Temp

−30-30°C

Pet safety

Toxic to pets

Mature size

55-65 cm tall

Care at a glance

Light

The Goldilocks zone. Not the south-facing windowsill (too hot, too direct), not the back of the room (too dim, growth stalls). More sun-tolerant than most hostas; morning sun or filtered afternoon light enhances and intensifies the golden-yellow colouration. Avoid harsh midday sun in hot climates. Partial shade is equally acceptable but may keep leaves more chartreuse than gold. If you can't decide, a free phone lux-meter app aimed at the leaf at noon should read between 800 and 1,500 lux.

Watering

Watering hosta 'august moon': when the top 3 cm of soil is dry, roughly every 6-7 days in summer. The number that matters isn't the day of the week — it's how dry the top 2-3 cm of the pot feels. A finger in the soil tells you more than a watering app. After every watering, tip the saucer. Regular, consistent watering maintains the large leaves in good condition. More sun exposure increases water demand. Mulching is recommended to reduce moisture loss between waterings.

Soil and pot

Hosta 'August Moon' grows best in fertile, humus-rich, well-draining loam. Enrich planting areas with compost or well-rotted organic matter. pH 6.0-7.0 is preferred. Avoid compacted or heavy clay soils which may cause root issues during the dormant winter period. 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

Hosta 'August Moon' sits happiest at around 45-65% humidity and −30-30°C (−22-86°F). Average garden humidity is entirely sufficient. In particularly hot, dry summers, additional watering (rather than misting) addresses humidity-related stress most effectively. If you keep the room above −30 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 hosta 'august moon' sparingly. Apply a balanced slow-release fertiliser in early spring. Because 'August Moon' is grown partly for its striking gold colour, a fertiliser with moderate nitrogen and good potassium and phosphorus encourages vibrant colour without excessive soft growth. 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 hosta 'august moon' in the Growli community. Each is annotated with the most common cause so you know where to start.

  • Bleaching in excess sun — While sun-tolerant, very intense direct afternoon sun can bleach the gold to washed-out cream with brown scorch patches; provide afternoon shade in hot regions.
  • Slug damage — Protect emerging spring foliage with slug deterrents before leaves unfurl fully.
  • Poor colouration in deep shade — Grown in heavy shade the leaves remain chartreuse-green rather than turning gold; site in a position with at least 2-3 hours of indirect morning light.
  • Crown rot — Avoid planting too deeply; the crown should sit just at or slightly above soil level.
  • Yellowing in late summer — Some early leaf yellowing from late August is normal seasonal senescence as the plant begins dormancy, not a nutrient deficiency.

Companion plants

Hosta 'August Moon' pairs well with Heuchera 'Palace Purple', Astilbe, Fern (Dryopteris), and Geranium. These are species with similar light and water needs, so you can group them in the same room or on the same shelf and water as a batch.

Propagation

Divide clumps in early spring or early autumn. 'August Moon' increases at a moderate rate; divisions every 4-5 years are sufficient to maintain vigour and refresh the planting. 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

Hosta 'August Moon' is toxic to pets. Hosta is listed by the ASPCA as toxic to dogs, cats, and horses. Saponins present throughout the plant cause gastrointestinal signs including vomiting, diarrhoea, and loss of appetite when ingested by pets. 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).

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.

Hosta 'August Moon' care — frequently asked questions

What is the common name for Hosta 'August Moon'?

Hosta 'August Moon' is most commonly called Hosta 'August Moon', but it is also known as August Moon Hosta, August Moon Plantain Lily. The names refer to the same species, so care instructions for Hosta 'August Moon' apply identically to anything sold as August Moon Hosta.

How much light does hosta 'august moon' need?

Hosta 'August Moon' grows best in medium indirect light (a couple of metres from a window). More sun-tolerant than most hostas; morning sun or filtered afternoon light enhances and intensifies the golden-yellow colouration. Avoid harsh midday sun in hot climates. Partial shade is equally acceptable but may keep leaves more chartreuse than gold.

How often should I water hosta 'august moon'?

Water hosta 'august moon' when the top 3 cm of soil is dry, roughly every 6-7 days in summer. Regular, consistent watering maintains the large leaves in good condition. More sun exposure increases water demand. Mulching is recommended to reduce moisture loss between waterings. 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 hosta 'august moon' toxic to cats and dogs?

Hosta 'August Moon' is toxic to pets. Hosta is listed by the ASPCA as toxic to dogs, cats, and horses. Saponins present throughout the plant cause gastrointestinal signs including vomiting, diarrhoea, and loss of appetite when ingested by pets.

What USDA hardiness zone does hosta 'august moon' grow in?

Hosta 'August Moon' is rated for USDA zone 3-9 and RHS hardiness H7. Outside that range, grow it as a container plant that overwinters indoors before the first hard frost.

Hosta 'August Moon' deep-dive guides

Every aspect of hosta 'august moon' care, each with its own calibrated guide:

Featured in these plant shortlists

Hosta 'August Moon' qualifies for 5 curated Growli shortlists — each one filtered objectively from our structured plant-care library, so the selection is consistent and checkable:

Related guides

Hosta 'August Moon' is also commonly called August Moon Hosta or August Moon Plantain Lily.