When do the flowers open?

The flowers typically open in the late afternoon or early evening and close by morning.

How often should I water it?

Water regularly, keeping the soil consistently moist but not waterlogged, especially during dry periods.

Does it need full sun?

Yes, it thrives in full sun to partial shade for the best flowering.

Can I grow it in a pot?

Yes, it grows well in containers, provided they offer good drainage.

Is it perennial or annual?

It's often grown as an annual in cooler climates but can be a tender perennial in warmer regions.

Plant guide

Four o'clock.

Mirabilis jalapa

Pronounced mi-RA-bi-lis JA-la-pa

Also known as Beauty of the Night, Beauty-of-the-night, Common Four O'clock, False Jalap, Four o'clock, Four o'clock flower, Four-O'Clocks, Four-o'clock

marvel of Peru — Photo by Ricard Busquets Reverte (CC BY) via iNaturalist

The Four o'clock is a vibrant, bushy plant known for its trumpet-shaped flowers that open in the late afternoon or evening. It's a fast-growing perennial that adds a splash of color and fragrance to the garden. This plant is also sometimes called the Marvel of Peru.

At a glance

Care level: Easy
Plant type: Perennial
Light: Full sun to partial shade
Indoor light: bright-indirect
Water: Every 3 to 7 days
Mature size: 2 to 3 feet tall and 2 feet wide
Growth rate: fast
Hardiness: USDA 7 to 10
Bloom time: Summer to fall

Care

Plant in well-draining soil and provide consistent moisture, especially during dry spells. Deadhead spent blooms to encourage more flowering. Protect from frost as it is perennial in warmer climates.

Watering: Water regularly, keeping the soil consistently moist but not waterlogged.
Feeding: Feed with a balanced liquid fertilizer every 4 weeks during the growing season.
Pruning: Prune back in late winter or early spring to encourage bushier growth and remove dead or damaged stems.
Repotting: Repot every 1-2 years in spring when the plant becomes root-bound.
Soil: Well-draining soil
Soil pH: Slightly acidic to neutral (6.0 to 7.0)
Temperature: 10 to 30°C
Humidity: 40 to 60%
Drought tolerance: moderate
Lifespan: Tender perennial, often grown as an annual
Fragrance: light
Deer and rabbits: low

Signs it needs repotting

Roots growing out of the drainage holes.
Water drains very slowly or not at all.
Plant appears stunted or growth has slowed significantly.
The soil dries out extremely quickly after watering.

Safety

People: All parts of the plant, especially the seeds, are considered toxic if ingested.
Pets: Can cause mild stomach upset if ingested by pets.
Children: The seeds are particularly attractive to children and are toxic if ingested, posing a choking hazard and risk of poisoning.
Contact allergens: No significant contact allergens are noted.
Airborne allergens: Pollen may cause respiratory irritation in sensitive individuals.
Edibility: While some sources mention the seeds are edible when cooked, it's best to avoid consuming any part of this plant due to potential toxicity.

How to identify it

Trumpet-shaped flowers
Flowers open late afternoon
Varied flower colors
Heart-shaped leaves
Bushy growth habit

Height: 0.6 to 0.9m
Spread: 0.45 to 0.6m
Leaves: green, deciduous
Flowers: pink, red, yellow, white, multi-colored, 2.5 to 5cm
Fruit: black, Late summer to fall

Common problems

Spider mites — Tiny pests that feed on plant sap, causing stippling and yellowing of leaves, often found in dry conditions.
Leaf spot — Fungal or bacterial infections causing spots on leaves, often exacerbated by wet foliage.
Root rot — Occurs in waterlogged soil, leading to wilting and eventual death of the plant.

Growing it

Propagation: seed, division
When to plant: spring, summer
Overwintering: In climates where it's perennial, protect the tuberous roots by mulching heavily after the foliage dies back. In colder regions, you can dig up the tubers after the first frost, store them in a cool, dry place like peat moss or sand, and replant them in spring.
In containers: Grows very well in containers, needing at least a 12-inch pot to accommodate its root system and allow for good drainage.

Seed

Sow seeds directly outdoors after the last frost, or start indoors 4-6 weeks prior.
Plant seeds about 1/2 inch deep in well-draining soil.
Keep the soil consistently moist until germination, which usually takes 1 to 3 weeks.
Thin seedlings to 12-18 inches apart once they are established.

Division

In early spring, carefully dig up the tuberous roots of established plants.
Divide the tubers into sections, ensuring each section has at least one 'eye' or growing point.
Replant the divided sections immediately into their desired locations or pots.
Water thoroughly after replanting.

Plant Four o'clock flowers where their evening fragrance can be enjoyed, and pair them with plants that bloom throughout the day for continuous garden interest.

Grows well with

Zinnia — Zinnias appreciate similar sunny conditions and well-drained soil, creating a vibrant, colorful display together.
Marigold — Marigolds offer a contrasting texture and color, and their reputed pest-repelling qualities can benefit the Four o'clock flower.
Cosmos — Cosmos share a similar airy growth habit and love full sun, making them a lovely companion for a cottage garden feel.

Keep away from

Waterlogged soil — This plant cannot tolerate constantly wet feet and is prone to root rot if drainage is poor.
Heavy shade — While it can tolerate some shade, deep shade will significantly reduce its flowering.

Similar species

Morning Glory — Both are known for opening their flowers at specific times of day (morning vs. afternoon/evening) and are popular garden annuals.
Petunia — Petunias offer a wide range of colors and bloom profusely in sunny locations, similar to Mirabilis jalapa.

Science

Family: Nyctaginaceae
Genus: Mirabilis
Order: Caryophyllales
Class: Magnoliopsida
Native range: South America
Conservation: Not of conservation concern.

It thrives in well-drained soils and can adapt to various light conditions, often naturalizing in disturbed areas.

Value to wildlife: nectar source
Pollinators: moths, hummingbirds
Uses: Ornamental, Cut flowers

Through the year

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Flowering

Fruiting

Foliage

Ecological indicators

Salinity: 3/9
Soil reaction: 6.5/9
Light: 7/9
Temperature: 8/9
Moisture: 5/9
Nutrients: 6/9

Taxonomy resolved against GBIF.

Questions people ask

When do the flowers open?: The flowers typically open in the late afternoon or early evening and close by morning.
How often should I water it?: Water regularly, keeping the soil consistently moist but not waterlogged, especially during dry periods.
Does it need full sun?: Yes, it thrives in full sun to partial shade for the best flowering.
Can I grow it in a pot?: Yes, it grows well in containers, provided they offer good drainage.
Is it perennial or annual?: It's often grown as an annual in cooler climates but can be a tender perennial in warmer regions.

Where the name comes from

Mirabilis jalapa is commonly known as the Four o'clock flower because its blooms open in the late afternoon. The scientific name, Mirabilis, means 'wonderful' in Latin, and jalapa refers to Xalapa, Mexico, from where it was first described.

Good to know

The flowers can come in multiple colors on the same plant, a phenomenon called 'chimera'.
Its name, Mirabilis jalapa, translates to 'wonderful' and 'from Xalapa', a city in Mexico.
It's a popular plant for attracting moths, which are important nocturnal pollinators.
The plant readily self-seeds, sometimes becoming quite prolific.

Is your four o'clock looking unwell?

This page is a general guide. Pocket Botanist diagnoses problems from a photo of your actual plant, works out watering for your light and conditions, and reminds you when care is due.

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This guide was generated with AI and checked against GBIF taxonomy. It is general information, not horticultural or veterinary advice. Read about how we build these guides.