Verbascum bomb. 'Polar Summer' (Mullein) — perennial

Overview

Verbascum bomb. 'Polar Summer' is a perennial in the genus Verbascum, part of the Scrophulariaceae family. Verbascum bomb. 'Polar Summer' grows best in full sun, and tolerates well-drained soils and neutral and alkaline pH. Its UK hardiness is rated H5. Suggested uses include borders, wildflower gardens and cottage gardens.

About

Verbascum bomb. 'Polar Summer' is a cultivar of mullein that produces tall, narrow flower spikes over an extended season from June to September. It typically forms a dense basal rosette of leaves before sending up a conspicuous flowering stem. As with other mulleins, it tolerates dry soils and is valued for long, steady flowering. The plant belongs to the Scrophulariaceae family and sits within the Verbascum genus.

About the genus

Verbascum is a genus of over 450 species of flowering plants, common name mullein, in the figwort family Scrophulariaceae. They are native to Europe and Asia, with the highest species diversity in the Mediterranean.

Wikipedia contributors, "Verbascum", CC BY-SA 4.0 — Verbascum

In the garden

A cultivar within the Verbascum genus, Verbascum bomb. 'Polar Summer' shares the group's origin across Europe and Asia, with the greatest species diversity around the Mediterranean. Members of this genus are commonly biennial or perennial; they spend an initial period as a ground-level rosette before producing a tall, central flowering stem. Flowering runs from June to September, giving several months of vertical colour where established. Plants are useful where soils tend to be dry: mulleins are noted for flowering reliably even in such conditions. Expect a season in rosette form followed by a decisive upright spike that carries numerous blooms; after flowering many mulleins set capsules containing fine seed. Give a free-draining spot and room for the flowering stems to rise clear of lower plants, and they will provide sustained interest through the summer months. Use Verbascum bomb. 'Polar Summer' as a vertical accent in perennial borders or in gravel and dry beds where a narrow, tall bloom stem is desirable. The rosette-to-spike lifecycle also makes it straightforward to predict when seed capsules will form, which helps if you wish to collect seed or allow self-sowing in a chosen area.

Growing conditions

Best soil and position for Verbascum

Sunlight: full sun
Soil type: well-drained
Soil pH: neutral, alkaline
Soil moisture: dry to medium
Aspect: south-facing
Exposure: sheltered to exposed
UK hardiness: H5

Plant details

Verbascum bomb. 'Polar Summer' size, habit and characteristics

Plant type: perennial
Suggested uses: borders, wildflower gardens, cottage gardens

Care notes

Pruning and caring for Verbascum bomb. 'Polar Summer'

Cultivation: Prefers well-drained soil; drought tolerant once established; avoid waterlogging
Pruning: Remove spent flower spikes to encourage prolonged blooming
Propagation: seed, basal cuttings

Frequently asked questions

How do I grow Verbascum bomb. 'Polar Summer'?

Prefers well-drained soil; drought tolerant once established; avoid waterlogging.

Where is the best place to plant Verbascum bomb. 'Polar Summer'?

Verbascum bomb. 'Polar Summer' prefers full sun. It suits sheltered to exposed positions.

What soil does Verbascum bomb. 'Polar Summer' need?

Verbascum bomb. 'Polar Summer' grows best in well-drained soil. It prefers neutral and alkaline soil. Aim for soil that stays dry to medium.

How do I prune Verbascum bomb. 'Polar Summer'?

Remove spent flower spikes to encourage prolonged blooming.

Is Verbascum bomb. 'Polar Summer' hardy in the UK?

Verbascum bomb. 'Polar Summer' has an RHS hardiness rating of H5, meaning it is hardy in most of the UK, tolerating -15 to -10°C.

How do I propagate Verbascum bomb. 'Polar Summer'?

Seed, basal cuttings.

More in the Verbascum genus

Browse all Verbascum →