Carthamus

( CAR - thuh - muss )

At-A-Glance Information

As a genus, these plants are commonly called Distaff Thistles, and species are native to Europe, North Africa, and parts of Asia. The flowers and seeds of certain species have been cultivated since ancient times as a flavoring and colorant for foods, commonly called Lupag Saffron or Kasubha. These thistle-like plants are easy to grow, and do well in mixed borders and beds, as pollinator magnets alongside crops, or cultivated for their petals in herb gardens. They also are at home in cottage and cut flower gardens.

Carthamus Species and Varietals

The genus Carthamus is a member of the plant family Asteraceae, and includes around 40 distinct species. They are relatives of other edible plants such as Artichoke, Cardoon, Dandelion, Calendula, and Wormwood. The genus name is derived from the Arabic 'kurtum' or the Hebrew 'qarthum', both of which mean 'to dye', referring to the flowers' use as a colorant for foods, clothing, and even makeup. Carthamus plants can grow in any zone. To find your zone, click here: Zone Map.

Carthamus lanatus (Downy Safflower, Woolly Distaff Thistle, Saffron Thistle, Wooly Starthistle)
This species is native to the Mediterranean Basin, where it grows in disturbed soils. It is considered to be a pasture and rangeland weed in many areas of the world, including North America and Australia. Flowers are bright yellow, and plants can reach over three feet tall when in bloom. Leaves are very spiny. Individual plants reach up to over 3 feet tall when mature and in bloom. This species is considered invasive in parts of North America (California and Oregon) and Australia.

Carthamus leucocaulos (Whitestem Distaff Thistle, Glaucus Starthistle)
These plants are native to Turkey, Greece, and the Aegean. Plants in this species typically reach up to between 14 and 32 inches tall when mature and in bloom, and stems and leaves are whitish-grey. Flowers are white. This species is considered invasive in California and western Australia.

Carthamus tinctorius (Safflower, Bastard Saffron, American Saffron, Dyer's Saffron, Saffron Thistle, Rouge Plant, Safflower Oil Plant, Parrot Seed)
This annual plant, first cultivated in Mesopotamia, is the source of Safflower Oil, extracted from seeds. It is among the worlds' oldest crops. Plants are highly branched, develop deep taproots, and produce bright yellow, orange, or red flowers. Individual plants reach up to between 12 and 60 inches tall when in bloom. Flowers can also be used as dye agents or a flavoring for various dishes.

Caring for Carthamus

Take care when working with these plants both in the landscape and when harvesting, as plant parts have sharp spines that will puncture skin and clothing. Make sure to wear gloves or other personal protective gear. Carthamus, or Distaff Thistle, is typically started in the garden by direct-sowing seeds. Specimens and starts may be available at specialty nurseries. Plant seeds 1/2 inch deep in rows spaced about 6-12 inches apart for best coverage and airflow. They perform well when planted in a space that receives full sun during the day; ideally between 6 and 8 hours. Ensure that soil is well-draining and has a pH of between 5.0 and 8.0 (acidic to slightly alkaline). These plants are pioneers, able to grow well in lean, dry soils. If local soils are particularly poor in nutrients or do not drain well, make sure to amend the planting area with plenty of organic compost before installing. Apply a layer of mulch around the planting area to suppress weed growth, maintain consistent soil temperatures, and to increase soil moisture retention.

Water new plantings regularly as they establish a strong root system in their new home. At maturity, Carthamus plants are considered to be very drought tolerant; they form a taproot that is able to access moisture deep in the soil profile. For best results, make sure to water regularly during their active growth and blooming periods, especially if you are planning on harvesting flowers or seeds. These plants do not require fertilizing; they are annuals, and can do well even in leaner soils. However, if local soil is particularly poor, the planting area can be amended each year with a layer of compost worked into the soil. Prune on a regular basis beginning in early springtime after new growth has emerged to encourage more branching, and deadhead to remove spent flowers. Otherwise, these plants do not need much in the way of pruning; they are annuals and are typically pulled and composted at the end of the growing season.

Harvesting Carthamus Plants
Carthamus is harvested for its flowers and seeds. Flowers can be used in fresh and dried arrangements (petals keep their color when dried). They are used to add pizzazz, height, and texture to arrangements, and also make great filler flowers and accents. Carthamus plants are in flower in spring and summertime, and are typically ready to be harvested 20 weeks after planting. Harvest flowers when half of the buds on a stem have opened in the late morning (after dew has dried but before the heat of the day starts creeping in). Remove all foliage that will sit below the water line, and drop stems into a bucket of cool water (if you will be using them fresh). They will last in a vase for between 7 and 10 days. For use as dried flowers, harvest stems when half of the buds are opened, and hang them upside-down in a cool, dark, dry place to cure.

The tender shoots and fresh petals of Safflowers are edible, adding to the usefulness of these plants in the landscape. Petals are collected when flowers have fully opened and show a good amount of color. To harvest them, simply pinch the flower tops and pull upwards to detach the petals. Place petals in a paper bag or other container while outdoors, and then bring them inside for processing. Petals can be dried on a tarp or drying rack. Alternatively, entire flowering stems can be harvested from plants and hung upside-down in a cool, dark, dry place. In either drying situation, check petals weekly for dryness and to ensure that no mold is forming. After they have been fully dried, they can be stored in an airtight container in a cool, dark, dry place like a cupboard. Dried petals can be used as a substitute for Saffron, though they lack the complex flavor and aroma. When Safflower petals are combined with other spices like Turmeric or Paprika (Capsicum annuum), the mixture can create a closer flavor and color profile to that of true Saffron.

A final part of the Safflower plant that is processed is the seed. Safflower seeds are harvested for their oil content, which ranges from 27% to 32%, and is rich in linoleic acid. Approximately 1 kilogram (2.2 lb.) of seeds can yield 0.2 liters (6.8 oz.) of safflower oil. The weight of seeds produced by plants varies greatly depending on the cultivar grown and the specific conditions it is grown in. On average, between 15 and 30 seeds are contained inside each flowering head. Each plant has a variable number of branches with between 1 and 5 flower heads each. The seeds are harvested when plants are mature and most of the foliage has turned brown. Seed heads should be dried, and seeds should be hard and easily separated from the chaff. If harvesting needs to happen before seeds are completely matured, entire plants can be harvested and hung upside-down in a cool, dark, dry area until they are ready. Harvest seeds by cutting off individual stems or entire plants. Separate the chaff from the seeds by using screens or winnowing. If seeds are not completely dried, they can be laid out in a cool, dark, dry place until they are. Store cleaned and dried sees in a sealed jar or container in a cool, dark, dry place if they will not be processed immediately. Seeds are typically pressed to remove oil.

Disclaimer: Information contained on this website is strictly and categorically intended as a reference to be used in conjunction with experts in your area. Foraging and consumption of plant parts should never begin without the guidance and approval of a local plant specialist. The providers of this website accept no liability for the use or misuse of information contained in this website.

Propagation

Carthamus, or Distaff Thistle, plants can be propagated either by using cuttings or from seed. To propagate your Distaff Thistle plant, follow the instructions below:

Propagating Carthamus by Seed

Keep in mind that the plant you get from seed will not necessarily mimic all of the characteristics of the parent plant. To propagate by seed, you will need a paper bag, a pot or tray filled with well-draining compost or other organic material, a spray bottle and a fork. If you don't have any potting medium on hand, you can make some. Just mix together equal parts (by volume) moss peat and horticultural-grade sand or grit sand. You will also, after a few weeks, need individual 3-inch pots for each seedling that grows.
Water your prepared seed tray or pot filled with soil, and ensure that good drainage is occurring. Place your seeds in your prepared pot or seed tray about a quarter inch to a half-inch under the soil surface. Cover them with soil and water with your spray bottle. Place your tray of seeds in a warm area that receives bright, indirect light. A greenhouse is the most ideal climate, but a planting tray inside a window will do as well. Germination usually takes 7-14 days from sowing. Once you begin to see seedlings sprout and they are able to be handled, transplant them to their own individual 3-inch pots, filled with the same potting medium as described in Step 1. Loosen the seedlings from the potting medium by digging down with the tines of your fork about an inch and a half, gently working the seedling up until it is out. Then, replant the seedling in its individual pot.
Keep the seedling's potting medium moist, but not wet, by spraying the soil with your spray bottle. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring (after the danger of frost has passed), when you can transplant it to its new home.
Alternatively, Carthamus seeds can be direct-sown into prepared garden beds. To direct-sow, simply plant seeds 1/2 inch deep in rows spaced about 6-12 inches apart for best coverage and airflow. Plants will be ready for harvesting approximately 20 weeks from sowing.