Why do the flowers close in the afternoon?

It is a natural response to the intensity of the sun and helps protect the pollen.

It is often considered a weed in lawns, but it is a lovely addition to wildflower meadows.

Plant guide

Jack-go-to-bed-at-noon.

Tragopogon pratensis

Pronounced tra-go-PO-gon pra-TEN-sis

Also known as Common Goat's Beard, Goat's-Beard, Goatsbeard, Jack-go-to-bed-at-noon

meadow salsify — Photo by Todd Boland (CC BY) via iNaturalist

This charming biennial wildflower is known for its bright yellow blooms that close up by midday. It is a common sight in meadows and along roadsides throughout Europe and North America. You will love how its fluffy seed heads resemble giant dandelions.

Another photo of Jack-go-to-bed-at-noon — Photo by Антон Кузьмицкий (CC BY) via iNaturalist

At a glance

Care level: Easy
Plant type: Biennial wildflower
Light: Full sun
Indoor light: Direct sun
Water: Every 7 to 14 days
Mature size: 3 feet
Growth rate: Medium
Hardiness: USDA 3 to 9
Bloom time: Late spring to mid summer

Care

Plant these in a sunny spot with well-draining soil to keep them happy. Watch for wilting if the soil dries out too much during the heat of summer. They are quite resilient and generally do not need much fussing.

Watering: Keep the soil consistently moist but never soggy for the best growth.
Feeding: A light application of balanced fertilizer in spring is plenty.
Pruning: Deadhead spent flowers if you want to prevent unwanted self-seeding.
Repotting: These plants have deep taproots and generally prefer being planted directly in the ground.
Soil: Well-draining, loamy soil
Soil pH: Neutral to slightly alkaline
Temperature: -20 to 30°C
Humidity: 40 to 70%
Drought tolerance: Moderate
Lifespan: Biennial, typically 2 years
Deer and rabbits: Moderate

Safety

People: This plant is not considered toxic to humans.
Children: The milky sap can be sticky and messy, but it poses no significant ingestion risk to children.
Contact allergens: The milky latex sap may cause mild skin irritation in sensitive individuals.
Airborne allergens: The wind dispersed seeds have fluffy pappi that can be a minor respiratory irritant.
Edibility: While the roots and young shoots are edible, ensure you have correctly identified the plant as it can look like other species.

How to identify it

Bright yellow ray florets
Long, grass-like basal leaves
Large, spherical seed heads
Milky sap in stems
Bracts longer than flower petals

Height: 0.3 to 0.8m
Spread: 0.15 to 0.3m
Leaves: green, blue-green, deciduous
Flowers: yellow, 3 to 6cm
Fruit: white, brown, Summer

Problems to watch for

Rust · Fungal spots may appear on leaves during humid weather.

By symptom

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Growing it

Propagation: seed
When to plant: spring, autumn
Overwintering: The plant forms a low rosette of leaves that will persist through the winter in mild climates. No special protection is needed as it is quite hardy.
In containers: It is not typically grown in containers as it has a long taproot that prefers deep garden soil.

Seed

1. Collect seeds when the pappus is dry and fluffy.
2. Sow directly into the garden in autumn or early spring.
3. Press seeds lightly into the soil surface.
4. Keep the area moist until germination occurs.

Plant this in a sunny meadow mix to allow its unique seed heads to stand out after the flowers fade.

Grows well with

Oxeye Daisy · They share similar meadow habitat requirements and bloom times.
Red Clover · It provides a nice color contrast and fixes nitrogen in the soil.

Similar species

Salsify · It is a close relative with purple flowers instead of yellow.

Science

Family: Asteraceae
Genus: Tragopogon
Order: Asterales
Class: Magnoliopsida
Native range: Europe and Western Asia
Conservation: It is a widespread and common species with no conservation concerns.

It thrives in open, sunny grasslands and disturbed soils where it can easily disperse its wind blown seeds.

Value to wildlife: nectar source
Pollinators: bees, butterflies
Uses: culinary roots, ornamental meadow plant

Through the year

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Flowering

Fruiting

Foliage

Ecological indicators

Salinity: 1/9
Soil reaction: 6/9
Light: 8/9
Temperature: 5/9
Moisture: 4/9
Nutrients: 5/9

Taxonomy resolved against GBIF.

Questions people ask

Why do the flowers close in the afternoon?: It is a natural response to the intensity of the sun and helps protect the pollen.
Is it a weed?: It is often considered a weed in lawns, but it is a lovely addition to wildflower meadows.

Where the name comes from

Tragopogon comes from the Greek words for goat and beard, referring to the hairy pappus of the seeds, while pratensis means of the meadow.

Good to know

The roots were historically eaten like parsnips.
It is a biennial or short lived perennial.
The seed heads look like giant dandelions.
It is native to Europe and parts of Asia.

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This guide was generated with AI on October 19, 2026 and checked against GBIF taxonomy. It is general information, not horticultural or veterinary advice. Read about how we build these guides.