Is Globe Thistle a Perennial? An Overview of this Unique Flowering Plant

With its spherical blooms topping tall, prickly stems, globe thistle is one of the most distinctive perennials for the summer garden. But what exactly is a perennial, and how does globe thistle fit into this category of plants? Let’s take a closer look at why globe thistle is indeed classified as a herbaceous perennial.

Perennials 101

Perennials are plants that live for multiple years unlike annuals that complete their entire lifecycle in one season. Perennials emerge each spring from rootstock or crowns that survived the winter. Some common examples are lavender, daylilies, iris peonies, and many ornamental grasses.

There are a few key traits that define perennials:

• They regrow from roots or crowns season after season.
• Their above ground growth dies back in winter in cold climates.
• They often have a dormant period in winter.
• They gradually spread larger over several years.

Herbaceous perennials have soft, flexible stems versus woody perennials like trees and shrubs which have rigid woody stems. Both types are considered perennials

Why Globe Thistle is a Perennial

Globe thistle (Echinops species) checks all the boxes that classify it as a herbaceous perennial

• It regrows each year from a basal crown and taproot.
• The foliage dies back completely in winter after a frost.
• The plant goes dormant over winter.
• Mature plants increase in size over time.

Globe thistle also exhibits other classic perennial traits:

• It flowers in mid to late summer on new growth.
• The blooms are long-lasting over weeks.
• It spreads slowly via self-seeding.
• It can be propagated by division or seed.

So there is no doubt – globe thistle is 100% a perennial plant.

The Perennial Nature of Globe Thistle

Now let’s look in more detail at how globe thistle grows over a full seasonal cycle to understand its perennial nature:

Spring

• Overwintering crown begins sending up fresh new foliage in spring when soil temperatures rise.
• Leaves start out silver-blue and become green.
• Flower stalks elongate, eventually reaching 1-4 feet tall depending on variety.

Summer

• Large spherical blooms composed of many tiny flowers open at ends of tall stems.
• Blooms last 4-6 weeks, opening sequentially up stems.
• Bees, butterflies and other pollinators flock to the nectar-rich blooms.
• Seeds begin developing in spent blooms if not deadheaded.

Fall

• Flowering ends with the onset of cooler weather.
• Seeds ripen and drop from faded blooms that weren’t deadheaded.
• Foliage turns beige-green and eventually dies back after frost.

Winter

• Plant enters dormancy once tops are killed by hard frost.
• Only the underground crown survives over winter.
• Seedlings from self-sown seeds emerge in spring.

As you can see, globe thistle follows the classic perennial pattern of vigorous new growth each spring, a long summer flowering period, foliage die-back in fall, and dormancy in winter – emerging again the next spring.

The Benefits of Globe Thistle as a Perennial

Growing globe thistle as a perennial in the garden has many benefits:

• No need to replant each year like annuals.
• Blooms for multiple years from one planting.
• Spreads and enlarges gradually over seasons.
• Easy to propagate by division or self-seeding.
• Provides food for pollinators over many weeks.
• Adds vertical color impact to borders.
• Works well as a cut flower.

Tips for Growing Globe Thistle

Caring for globe thistle is easy since it’s such a tough, adaptable perennial. Here are some tips:

• Plant in full sun and well-drained soil.
• Avoid fertilizing which causes floppy growth.
• Cut back finished blooms to encourage rebloom.
• Leave some blooms to self sow propagation.
• Divide every 2-3 years to control spread.
• Cut back stems in fall once foliage dies back.

With its ability to survive winters and regrow for many seasons, globe thistle is clearly a herbaceous perennial plant. Its lifecycle follows the expected perennial pattern of vigorous growth in spring and summer, dieback in fall, and dormancy in winter. Globe thistle exhibits all the characteristics and benefits of a classic perennial, making it a great addition to the garden.