Growli

Plant care

Acorn squash (pepper squash) care

Cucurbita pepo

Also called pepper squash, Des Moines squash.

RHS H2USDA Grown as an annual in zones 3-10Pet-safeIndoor Bush: 1 m

Watering rhythm

Direct sun (at least 4-6 hours)

Deep watering twice a week

Light

Direct sun (at least 4-6 hours)

Soil

Rich well-drained loam

Humidity

40-70% (outdoor)

Temp

18-29°C

Pet safety

Pet-safe

Mature size

Bush: 1 m

Care at a glance

Light

Most houseplants will scorch where acorn squash thrives. Give it the windowsill you'd otherwise leave empty because everything else burned there. 6-8 hours of direct sun. A plant moved abruptly from low light to direct sun bleaches in 48 hours — always acclimatise over a week.

Watering

For acorn squash in the ground or in a bed, aim for deep watering twice a week. Soak the root zone rather than misting the foliage; deep, less-frequent watering trains roots downward and produces a more drought-resilient plant by mid-season. Steady moisture; ease back as fruit ripens.

Soil and pot

Acorn squash grows best in rich well-drained loam. Compost-rich; pH 6.0-7.0. 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

Acorn squash sits happiest at around 40-70% (outdoor) humidity and 18-29°C (65-85°F). Outdoor humidity rarely matters. If you keep the room above 18 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 acorn squash sparingly. Balanced feed at planting; high-potash feed once flowering. 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 acorn squash in the Growli community. Each is annotated with the most common cause so you know where to start.

  • Powdery mildewLate-summer fungal disease; water at soil level.
  • Squash bugsPick eggs off undersides; row cover early in season.
  • Blossom-end rotInconsistent watering.
  • Splitting fruitDrought followed by heavy rain.
  • No fruit setPoor pollination; hand-pollinate.

Companion plants

Acorn squash pairs well with Corn, Bean, and Marigold. These are species with similar light and water needs, so you can grow them in the same bed or container without conflict.

Propagation

Direct-sow after frost, or indoors 3-4 weeks before last frost. 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

Acorn squash is pet-safe. Cucurbita species are not listed by the ASPCA. Safe around cats and dogs. 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.

Acorn squash care — frequently asked questions

What is the common name for Cucurbita pepo?

Cucurbita pepo is most commonly called Acorn squash, but it is also known as pepper squash, Des Moines squash. The names refer to the same species, so care instructions for Acorn squash apply identically to anything sold as pepper squash.

How much light does acorn squash need?

Acorn squash grows best in direct sun (at least 4-6 hours). 6-8 hours of direct sun.

How often should I water acorn squash?

Water acorn squash deep watering twice a week. Steady moisture; ease back as fruit ripens. 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 acorn squash toxic to cats and dogs?

Acorn squash is pet-safe. Cucurbita species are not listed by the ASPCA. Safe around cats and dogs.

What USDA hardiness zone does acorn squash grow in?

Acorn squash is rated for USDA zone Grown as an annual in zones 3-10 and RHS hardiness H2. Outside that range, grow it as a container plant that overwinters indoors before the first hard frost.

Acorn squash deep-dive guides

Every aspect of acorn squash care, each with its own calibrated guide:

Featured in these plant shortlists

Acorn squash qualifies for 1 curated Growli shortlist — each one filtered objectively from our structured plant-care library, so the selection is consistent and checkable:

Related guides

Acorn squash is also commonly called pepper squash or Des Moines squash.