Verbena Bonariensis Seeds

If you ever wonder how garden designers create those effortless, floating clouds of purple, this is the plant. Verbena bonariensis produces tall, wiry, almost invisible stems topped with tight clusters of electric-purple flowers.

It is known as a "see-through" plant. Because the stems are so thin and sparse, you can plant it right at the front of a border, and you will still be able to see the plants behind it. It adds height, movement, and an airy violet haze to the garden without creating a heavy block of foliage.

Why Your Garden Needs 'Verbena Bon'

We love this plant because it is arguably the best butterfly plant in the UK. On a sunny day in August, the flower heads are often invisible beneath the weight of Red Admirals, Peacocks, and Painted Ladies. It is a pollinator service station.

It is also incredibly architectural. The rigid stems stand up well to the wind and look beautiful when frosted in winter. Leaving the seed heads standing provides vital food for birds and structure for the winter garden.

Understanding the Plant: What is a Short-Lived Perennial?

Verbena bonariensis is a Short-Lived Perennial (often treated as a Hardy Annual in the North).

It usually survives the winter in the south of the UK (Hardiness H4), but a harsh frost can kill it.
The Survival Strategy: Don't worry if the parent plant dies! This plant is a prolific self-seeder. If you leave the flower heads on over winter, you will find dozens of free seedlings popping up in spring to replace the old plant.
Top Tip: Don't mulch too heavily around the crown in winter; it hates sitting in wet compost.

Growing Guide: How to Sow and Grow

Verbena needs patience; germination can be irregular.

🌱 Germination:
Sow indoors from February to April. Surface sow onto moist compost and **do not cover** (seeds need light to germinate). Keep warm (18-21°C). Germination can be slow and erratic (14-28 days). If nothing happens after a month, put the tray in the fridge for 2 weeks (cold stratification) to wake the seeds up.

Where to Sow:
It demands **full sun** and **well-drained soil**. It is drought tolerant once established. It looks best planted in drifts rather than single specimens.

Care While Growing:
This plant is low maintenance. It rarely needs staking despite its height (up to 1.5m) because the stems are stiff and square. Leave the stems standing all winter for structure and cut them back to the base in spring when new growth appears at the ground level.

Plant Specifications

Here is a quick reference guide to the key features.

My Recommended Garden Companions

Verbena Bonariensis creates a "purple haze" that needs solid colours or contrasting shapes to anchor it:

• 🍂 Rudbeckia 'Autumn Forest': The ultimate late-summer pairing. The rich gold and bronze of the Rudbeckia daisy heads creates a stunning complementary contrast to the electric purple of the Verbena.
• ☁️ Cosmos 'Purity': For a fresh, light feel. The large, white saucer flowers of Cosmos stand out brilliantly against the thin purple stems of the Verbena, creating a floating, cloud-like effect.

📅 Sowing & Flowering Calendar

Sow indoors in spring. Blooms from mid-summer until the first hard frost.

(↔️ Swipe chart to see all months)