Blue-eyed Mary

Blue-eyed Mary: how do you recognise it?

Habit

Low carpet 10–15 cm tall and 50 cm wide or more, spreading by overground runners.

Foliage

Oval with a heart-shaped base, 3–7 cm, softly hairy and fresh green; evergreen in mild winters.

Flower

Small five-petalled flowers of about 1 cm in loose sprays, from March to May.

Colour

Bright blue with a white eye.

Runners

Long overground runners that root where they touch the soil and form new plants.

Flowering: March–May · Plants: March–April and September–October · Pruning: June

Why grow it?

• Bright blue flowers from March to May, when the garden has hardly any colour yet.
• Forms a dense carpet by itself and so suppresses weeds under trees and shrubs.
• Bees and early bumblebees find pollen and nectar.
• The fresh green foliage stays largely green in mild winters.
• Lovely combined with snowdrops, daffodils and other spring bulbs.

Blue-eyed Mary: where does it grow best?

• Partial shade to shade, for instance under deciduous trees and shrubs.
• Humus-rich, moisture-retentive loam or clay, acid to chalky.
• Moderately moist: it does not tolerate long summer drought.
• Plant 25–30 cm apart; it covers the surface by itself in one or two seasons.

Light

Partial shade and shade

Soil type

Loam or clay

Acidity

Not fussy

Moisture

Normal

Size

0.15 m tall, 0.5 m wide

Hardiness

Hardy (to -25 °C)

Goes well with

• Snowdrop: Flowers in the same shade and comes up through the blue carpet.
• Daffodil: Yellow spring bulbs rise above the low blue carpet.
• Lenten rose: Hellebores flower at the same time and share the same partial shade.
• Ferns: Fresh green foliage that frames the blue carpet later in the season.

Blue-eyed Mary: when and how to plant it?

Plant in March–April and September–October.

1. Plant in March–April or in September–October, when the soil is not frozen or too wet.
2. Loosen the soil and mix in a little leaf mould, so that it is moisture-retentive and humus-rich.
3. Set the plants at the same depth as in their pots and firm the soil well.
4. Keep 25–30 cm between plants; the runners fill the gaps.
5. Water in at once and lay a thin layer of leaf mould around the plants.

Care

Water

In the first year, water regularly in dry weather; after that only in long summer droughts.

Feeding

A thin layer of compost in spring is enough.

Mulching

A thin layer of leaf mould in autumn keeps the soil moist and feeds the carpet.

Runners

In spring, dig out runners that stray too far and replant them elsewhere or discard them.

Tidying

In spring, remove fallen leaves and dead pieces if necessary so the fresh foliage and flowers show well.

Tip: Use it as an early ground cover under shrubs and trees, together with spring bulbs, and dig out the runners that spread too far. Keep the soil lightly moist in summer.

Blue-eyed Mary: when to prune it?

Pruning months: June.

When: It is hardly pruned. In June, after flowering, trim a mat that has grown too large or untidy.

How:

• Cut off faded flower sprays and tired foliage after flowering.
• Keep the edge in check by cutting away runners with a spade.
• Remove dead or damaged pieces from the carpet.

Caution: It spreads fast by overground runners and can smother smaller, weaker plants: watch the edge and remove runners in good time.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Lifting runners

In spring or September: cut rooted runners away with a spade and plant them elsewhere in moist soil.

Division

In spring or September: lift a piece of the carpet, divide it and replant.

Seed

Sow fresh seed in summer in a seed tray in partial shade; it also self-seeds.

Blue-eyed Mary: how does it get through the winter?

Hardy to −25 °C.

• Hardy down to about −25 °C: no protection is needed in Belgian winters.
• The foliage stays green in mild winters; in hard frost it partly dies back and regrows in spring.
• In a pot or bowl: use a humus-rich compost and do not let it dry out in winter.

Diseases and pests

• Slugs: Holes in young leaves in spring. Collect them in the evening or lay a ring of coarse grit around the plant.
• Drought stress: Limp, brown leaves after a dry summer. Give water and more shade; the carpet usually recovers in autumn.
• Powdery mildew: White powder on the leaves in dry shade. Mulch, water, and cut off affected leaves.
• Smothering: The runners push into neighbouring plants. Remove the runners every year or plant it in a defined space.

Through the year

• March: First flowers. Plant. Remove fallen leaves.
• April: Full flower. Plant or divide.
• May: Last flowers. Water in dry weather.
• June: Trim the carpet. Lift runners.
• July: Water in long dry spells.
• September: Plant or divide. Lift runners.
• October: Plant. Leaf mould as mulch.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Did you know?

• The species name verna comes from the Latin word for spring: it flowers in early spring.
• In English it is called ‘blue-eyed Mary’, a name that suits its blue flowers with a white eye.
• It belongs to the borage family, like forget-me-not, borage and comfrey.