Echinops sphaerocephalus Seeds | Glandular Globe Thistle

Large pale blue globe heads on a tall glandular stem with spiny lobed leaves — Glandular Globe Thistle (*Echinops sphaerocephalus*): Asteraceae, rough dry ground from southern Europe to western Siberia.

LATIN NAME: Echinops sphaerocephalus

COMMON NAME: Glandular Globe Thistle

Plant Profile

Glandular globe thistle is the tall, coarse, slightly sinister relative of the neat blue globe thistles of the border. It grows one and a half to two and a half metres, with a stout stem, deeply lobed and spiny leaves, and a covering of sticky glandular hairs that give the plant its name and a faintly medicinal smell on a hot day. The flower heads are large, round and pale grey-blue to white, opening over a long period in midsummer and swarming with bees. It is a plant of rough ground, roadsides and dry scrub from southern Europe through the Caucasus to western Siberia, and it has escaped cultivation across much of northern Europe and North America, where it is now listed as an invasive species in several states. It is impressive in a wild garden and a liability in a small one, because it seeds freely and the seedlings are tough.

Science & Biotechnology

Echinops sphaerocephalus is a hexaploid relative of the smaller globe thistles, with 2n = 90 or thereabouts, and its larger size and glandular indumentum separate it from E. ritro and its allies. The sticky hairs are glandular trichomes that secrete resins and sesquiterpene lactones, compounds that deter herbivores and have been studied for allelopathic and antimicrobial activity. The globe is a pseudanthium of one-flowered capitula, as in the rest of the genus, and the flowers are protandrous, with the stamens shedding pollen before the stigma is receptive, which promotes outcrossing. The seed is a large achene with a scaly pappus, and it is spread by wind and by attaching to fur. In North America the species is a documented invader of prairies and roadsides, and it is on noxious weed lists in several states.

Uses & Benefits

In a large wild garden or a meadow it is a bold plant: tall, architectural, and one of the best summer nectar sources for bees, which work the globes in numbers. The heads dry well and are used in arrangements. It has a folk medicinal record in central Europe as a bitter tonic and a diuretic, and the sesquiterpene lactones in the glandular hairs are of pharmacological interest, but it is not a plant to self-medicate with. The stems have been used for rough fibre. Its main drawback is its fertility: a single plant can produce thousands of seed, and the seedlings establish on any bare ground. Where it is listed as invasive, it should not be planted at all, and existing plants should be deadheaded before the seed ripens.

Growing from Seed

Sow in late winter or early spring, on the surface of a gritty mix, and press the seed in without covering it. Cold stratification for four weeks helps, and germination takes two to four weeks at 18 to 22 degrees. Grow the seedlings in full sun and do not overwater them, since damping off is the main risk. Pot on into a gritty, low-fertility mix, and plant out in autumn in full sun and well-drained soil. It will grow in poor ground and does not need feeding, which makes it useful on a rough bank. Deadhead before the seed ripens unless you want it to spread, and cut the stems to the ground in early spring. It is a plant for a large garden, not a small one.

Our Take

A tall, bold globe thistle for a wild garden, superb for bees and far too fertile for a small border. Deadhead it, or do not plant it.

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