Saffron Thistle Plant Care

Saffron Thistle (Carthamus lanatus) belongs to the Asteraceae family within the Carthamus genus. Saffron Thistle is also known as Wild Saffron, Cotton Thistle, Kentrophyllum lanatum.

Saffron Thistle displays an upright, branching shrub growth habit, reaching up to 3 ft tall with a spread of approximately 2 ft. Saffron Thistle produces bright orange, thistle-like flowers.

Leaf size: approximately 4 inches.

Water a young or newly planted Saffron Thistle every 7–10 days, soaking the whole root zone, until it is established — usually one to two growing seasons. Established shrubs mainly need water during long dry spells. In a container, water whenever the top few centimetres of soil are dry.

Saffron Thistle thrives in full sun.

Carthamus lanatus tolerates temperatures of 60–80°F. Saffron Thistle prefers humidity levels of 40–60%.

Well-draining sandy loam with added organic matter. Good drainage is essential for Saffron Thistle to prevent waterlogging, which leads to root rot and fungal issues.

Feed Saffron Thistle every 6 months during the growing season with a balanced, slow-release fertilizer at the rate on the label. Established shrubs in good soil often need little extra feeding, so let weak growth or pale foliage guide you.

Stop feeding by late summer so new growth can harden before winter.

The PlantoScan app can remind you when to water and when to fertilize each plant.

Choose a spot with full sun and well-draining sandy loam with added organic matter. Avoid low spots where water collects after rain.

Saffron Thistle is suited to USDA Zone 13a.

Plant container-grown or balled-and-burlapped shrubs in spring or early autumn, setting the root flare at soil level, and water well after planting.

Saffron Thistle can spread to about 2 ft (0.6 m) and reach about 3 ft (1 m) tall. Space plants about 2 ft (0.6 m) apart so mature crowns don't crowd each other, and plant at least half that distance from buildings, fences and paths.

Planning a row or hedge? Try the plant spacing calculator.

Prune Saffron Thistle while it is dormant in late winter: first remove dead, damaged and crossing branches, then thin lightly for shape.

If it flowers in spring, prune right after flowering instead so you don't remove next year's buds. Never take off more than about a quarter of the shrub in one year.

Saffron Thistle is frost-tender (hardy to USDA zone 13). In colder areas grow it in a container and move it to a bright, frost-free place before the first frost.

Saffron Thistle can be propagated through seeds.

See all plants toxic to cats and plants toxic to dogs.

Saffron Thistle is susceptible to aphids, spider mites, whiteflies. Inspect the foliage regularly, especially along leaf undersides and stems. Treat infestations promptly with insecticidal soap or neem oil to prevent spread.

Yellow leaves, brown tips or drooping? See common plant problems and how to fix them.

Saffron Thistle grows outdoors in USDA Zone 13a. It survives winters down to planting zone 13a. In cooler regions, grow Saffron Thistle as a houseplant or bring it indoors before the first frost.