Carthamus Plant Growing & Care Guide for Gardeners

In this Gardener's HQ guide, we'll explore cultivating Carthamus plants in your garden, indoor spaces, and other settings.

Safflower, False Saffron: Cultivation & Garden Use

Carthamus is a hardy annual that flowers in the middle of summer. it can reach a height of about one metre.

Carthamus has tubular flowers that may be yellow or orange in colour.

Carthamus is often used for culinary purposes.

Names of some of the plants in the genus include Safflower (Carthamus tinctorius), False Saffron and Saffron thistle.

Carthamus lanatus
Carthamus lanatus by Tony Rodd.

Carthamus tinctorius
Carthamus tinctorius by Yaisog Bonegnasher.

Carthamus Growing and Care Guide

Common Names: Safflower, Saffron Thistle, False Saffron, Distaff Thistle.
Life Cycle: Hardy annual.
Height: 30 to 36 inches (75 to 92 cm).
Native: Mediterranean.
Growing Zone: Zones 3 to 9.
Flowers: Summer.
Flower Details: Yellow or orange. Tubular.
Foliage: Thistle-like. Prickly.
Sow Outdoors: 1/4 inch (6mm). Early spring before last frost or late autumn. Spacing 6 to 10 inches (15 to 25 cm).
Sow Indoors: Peat pots. Germination time: one to two weeks. Temperature 60 to 70°F (15 to 21°C). Seven or eight weeks before expected last frost. Transplant outdoors following the last frost.
Requirements: Full sunlight. Soil pH 6 to 7. Dry soil. Light soil. Poor soil. Use mesh to protect from rabbits.
Family: Asteraceae.
Miscellaneous: Many culinary uses, often sold as 'saffron' in markets.

How to Grow Carthamus (Safflower)

When growing Carthamus from seed outdoors it should be planted at a depth of 6 mm in light soil of pH 6 to 7 in the early spring, before the last frost of the season.

When growing Safflower from seeds indoors they should be sown in peat pots about 8 weeks before they are ready to be transplanted in mid-spring.

Safflower seedlings should be planted out with a spacing of 15 to 20cm in a sunny part of the garden.

Harvesting Carthamus for Use in Cooking

If you are growing Carthamus for culinary purposes then the flower heads should be cut off at the end of summer, and dried.

Carthamus makes a good replacement for expensive saffron. In addition to direct use in cooking, safflower oil is often considered a healthier option than using sunflower oil.

Common Questions

How many members does the Carthamus genus have?

The Carthamus genus comprises around 12 species, including the well-known Safflower.

Do members of Carthamus make a good garden or landscaping plant?

Yes, Carthamus species, particularly Safflower, can add vibrant color to gardens. They're drought tolerant and can work in xeriscapes.

Which Carthamus species are most frequently grown by gardeners?

The most commonly cultivated species is Carthamus tinctorius (Safflower), grown for its orange, thistle-like flowers.

Are members of the Carthamus plant genus fragrant?

Carthamus plants are not known for their fragrance but for their thistle-like, brightly colored flowers.

What is the perfect location to grow Carthamus?

Carthamus plants prefer full sun and well-drained soil. They are drought tolerant and suitable for dry, sandy soils.

Is Carthamus invasive in the USA?

At present, Carthamus species are not classified as invasive in the USA. However, they can spread in favorable conditions, so monitor their growth.

How do I remove Carthamus plants from my garden?

Removing Carthamus involves pulling or digging up the plants. Its seeds can be prolific, so monitor for seedlings.


The Carthamus genus, part of the Asteraceae family, is native to the Old World. The most known species, Carthamus tinctorius or safflower, is an annual plant recognized for its thistle-like appearance and vibrant orange or yellow flowers that bloom in summer.

To cultivate Carthamus, plant them in a sunny location with well-drained soil. They can be grown from seeds sown in the spring. Regular watering is necessary, but they are quite drought-tolerant once established. They're often used in borders, wildflower gardens, or as cut or dried flowers for their striking color and texture.

I hope that you enjoyed this guide on how to grow Carthamus plants. You may also enjoy the following Gardener's HQ Asteraceae growing guides: How to grow Tahoka daisy and Felicia plants.