Geranium pratense 'Plenum Caeruleum' (Crane's Bill) — Mound-forming or spreading

Overview

Geranium pratense 'Plenum Caeruleum' is a mound-forming or spreading perennial in the genus Geranium, part of the Geraniaceae family, with deciduous or semi-evergreen; rounded, palmately lobed, often aromatic foliage. It typically grows around 1.2 m tall. Geranium pratense 'Plenum Caeruleum' grows best in full sun to partial shade, and tolerates most soils and acid and neutral or alkaline pH. Its UK hardiness is rated H5–H7. Suggested uses include borders, cottage gardens and wildflower gardens. It is native to Belgium.

About

Geranium pratense 'Plenum Caeruleum' is a perennial Geranium that forms a spreading mound and produces pale violet flowers from June to September. Leaves are rounded and palmately lobed, either deciduous or semi-evergreen and often aromatic. It reaches about 1.2 m and suits a wide range of garden soils provided they are well drained but not parched. Plant it in full sun to partial shade in either exposed or sheltered spots.

Wikipedia contributors, CC BY-SA 4.0 — Geranium pratense

About the genus

Geranium is a genus of 422 species of annual, biennial, and perennial plants that are commonly known as geraniums, hardy geraniums, or cranesbills. They are found throughout the temperate regions of the world and the mountains of the tropics, with the greatest diversity in the eastern part of the Mediterranean region.

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

In the garden

Geranium pratense 'Plenum Caeruleum' belongs to the Geraniaceae and originates from Belgium; it establishes as a mound-forming or spreading perennial that typically reaches about 1.2 m. Flowering runs from June to September, when pale violet blooms appear above rounded, palmately lobed foliage which may be deciduous or semi-evergreen. Position plants in full sun to partial shade; the species tolerates almost any reasonable soil type — loam, chalk, sand or clay — and accepts acid, neutral or alkaline pH. Soils should be well drained without being bone dry. It is rated H5–H7, meaning hardy to fully hardy, so plants will survive ordinary UK winter conditions in both sheltered and exposed locations. Use Geranium pratense 'Plenum Caeruleum' in mixed herbaceous borders, cottage garden schemes and wildflower areas where a summer display of pale violet is wanted. Its mound-forming habit gives structure at about 1.2 m, making it a useful mid-border element and a summer-long presence from June to September.

Growing conditions

Best soil and position for Geranium

Sunlight: Full sun to partial shade
Soil type: Almost any reasonable soil — loam, chalk, sand or clay
Soil pH: Acid, neutral or alkaline
Soil moisture: Well drained but not parched
Aspect: Any
Exposure: Exposed or sheltered
UK hardiness: H5–H7

Plant details

Geranium pratense 'Plenum Caeruleum' size, habit and characteristics

Plant type: Perennial
Habit: Mound-forming or spreading
Foliage: Deciduous or semi-evergreen; rounded, palmately lobed, often aromatic
Height: 1.2 m
Suggested uses: Borders, cottage gardens, wildflower gardens
Native to: Belgium

Care notes

Pruning and caring for Geranium pratense 'Plenum Caeruleum'

Cultivation: Among the least demanding of perennials, asking only for reasonable drainage and an open position. Shear the whole plant back hard after the first flush and water it in; most kinds then produce fresh foliage and a second showing by late summer.
Pruning: Cut back to a low framework after the first flowering to renew the foliage and prompt repeat bloom. Tidy any remaining growth in late autumn or early spring.
Propagation: Divide in spring or autumn. Many species self-seed freely, and basal cuttings suit cultivars that resent disturbance.
Pest resistance: Largely untroubled, though vine weevil grubs attack the roots of container plants and sawfly larvae occasionally strip leaves.
Disease resistance: Powdery mildew and rust may appear on congested plants in a dry summer; shearing back usually resolves both.

Frequently asked questions

How do I grow Geranium pratense 'Plenum Caeruleum'?

Among the least demanding of perennials, asking only for reasonable drainage and an open position. Shear the whole plant back hard after the first flush and water it in; most kinds then produce fresh foliage and a second showing by late summer.

Where is the best place to plant Geranium pratense 'Plenum Caeruleum'?

Geranium pratense 'Plenum Caeruleum' prefers full sun to partial shade. It suits exposed or sheltered positions.

What soil does Geranium pratense 'Plenum Caeruleum' need?

Geranium pratense 'Plenum Caeruleum' is adaptable and grows happily in most soil types, including almost any reasonable soil — loam, chalk and sand or clay. It prefers acid and neutral or alkaline soil. Aim for soil that stays well drained but not parched.

How do I prune Geranium pratense 'Plenum Caeruleum'?

Cut back to a low framework after the first flowering to renew the foliage and prompt repeat bloom. Tidy any remaining growth in late autumn or early spring.