Pratia: planting, cultivation, maintenance

Description and Botany

The Pratia is a perennial ground-cover plant from the Campanulaceae family. The genus includes around twenty species native to Australia and New Zealand, among which the Pratia pedunculata or Isotoma fluviatilis and its cultivars are the most common in our gardens. You may also encounter Pratia angulata, with its zygomorphic flowers, meaning they display a particular symmetry.

It features a very carpet-like growth habit, with long, ramified stems that root into the soil at each node and an underground root network extending about ten centimetres deep and spreading quickly sideways. This allows the plant to colonise the soil surface, theoretically without limits. The height of the carpet will not exceed 3 to 5 cm.

This lovely plant can become invasive, but it forms a beautiful flowering cushion that can replace grass in less-trodden areas of the garden.

Pratia pedunculata and Frankenia laevis

Its short, running stems bear small leaves, 5 to 10 mm long, more or less evergreen depending on the severity of winter. They are alternate, bright green to soft green in colour, ovate in shape, delicately dentate at the edges, resembling water droplets. In case of pronounced summer drought, the foliage dries out and becomes deciduous, but the plant eventually reappears when the rains return.

The abundant flowering occurs in spring, usually in May-June, and often reappears in July until autumn, sometimes until frost, if the soil remains moist. Tiny star-shaped, solitary, and erect flowers dot this leafy carpet. They are composed of 5 petals, most often pure white, or white veined with purple, sometimes blue, like the very luminous Pratia pedunculata ‘County Park’. Borne on long peduncles, they stand out well above the foliage. They give way to small, round or ovoid fruits of a plum colour.

Main species and varieties

Pratia angulata

A charming ground cover with tender green foliage and white spring flowering. Excellent for creating volume effects, it quickly colonises open spaces.

• Flowering time June, July
• Height at maturity 5 cm

See the product sheet

Pratia pedunculata

Robust and hardy, it will adapt to many growing conditions.

• Flowering time June to September
• Height at maturity 5 cm

See the product sheet

Pratia pedunculata County Park

A delightful form with deep blue flowering! It can be used as an alternative to grass, especially in areas difficult to mow or seed.

• Flowering time June to September
• Height at maturity 5 cm

See the product sheet

Pratia pedunculata Alba

This cultivar stands out for its white flowers. It spreads enthusiastically into a wide, low tapetum, in fresh soil.

• Flowering time June to September
• Height at maturity 5 cm

See the product sheet

Planting Pratia

Where to Plant It?

Often used as an alternative to grass in moderately trampled and small areas of the garden, as it requires regular watering (to be adjusted depending on the region), the Pratia works wonders in our continental gardens. Easy to grow, it will thrive in slightly shaded areas, or even in full shade in regions south of the Loire, as it dislikes scorching sun during the hottest hours of summer.

To stay beautiful and maintain its foliage, it requires regular watering depending on the region and rainfall, although it can withstand temporary drought. Its above-ground parts disappear in case of severe drought or lack of water in summer. It prefers fresh to moist, ordinary, well-drained, and humus-bearing soils. It dislikes stagnant moisture in winter.

This is a vigorous ground cover whose foliage persists in mild climates but will be scorched by frost below -10°C, while the root system can withstand frosts of around -15°C.

Very low-growing, it makes an excellent alternative to grass in slightly neglected and less frequented areas of the garden, where it will prevent weeds from taking hold. It will not tolerate heavy foot traffic.

However, ensure it has enough space, as it does not tolerate competition and tends to quickly smother other plants.

It flowers in the gaps between paving stones and stepping stones, softens the edge of a path, or forms a beautiful ground cover in woodland areas or hard-to-mow zones. Given its expansive, even invasive nature, it’s best planted away from perennial beds. It can also be planted in a Japanese or Zen garden to create minimalist scenes. It also thrives in pots or troughs.

Pratia pedunculata (© Peganum)

When to Plant It?

Planting Pratia is best done in autumn from September to November or in spring from March to May, avoiding periods of frost and drought.

How to Plant It?

In the ground

Plan for at least 7 buckets per square metre, spaced about 30 cm apart to allow the stems to spread and ensure good coverage. If your soil is heavy, very clayey, and too compact, mix in river sand and compost. The soil should be well loosened to a good depth.

• Dig a hole 2 to 3 times wider than the root ball
• Create a drainage layer at the bottom of the hole by spreading gravel to a depth of 10 cm
• Place the plant in the centre
• Fill in with garden soil enriched with a bit of compost
• Water thoroughly

In pots

Choose a wide, shallow container with drainage holes, from which it will spill attractively. Ensure the substrate remains moist, especially in summer.

• Spread a good layer of drainage material (gravel or clay pebbles) at the bottom of the pot
• Plant in a well-draining mix of garden soil and compost, with added coarse sand
• Water regularly

Maintenance and Care

The pratia requires almost no maintenance. Water regularly during the first year after planting to help it establish its roots. It does not require mowing and only needs consistent watering during drought and extreme heat. Adjust the watering frequency according to your climate: in the South of France, one to two waterings per week are often necessary to maintain the foliage in summer.

Weed regularly around its base until it fully covers the soil.

In winter, in harsh regions, we recommend mulching the stump with a thick layer of dried leaves or straw.

If you wish to control its spread, manually remove any excess rooted stems.

In pots, the soil dries out faster than in the ground, so water regularly throughout the summer to keep the substrate moist and encourage the development of long stems.

Pratia angulata

Multiplication

Propagating Pratia is simply done by taking rooted stems.

In spring or autumn, pull up the stolons and replant them in moist, sandy soil. Ensure you water regularly to encourage establishment.

Associate

The Pratia is ideal for filling gaps in paving or hard-to-reach corners. Particularly expansive once acclimatised to the garden, it’s best to avoid planting it in a rockery or among perennial plants. So, although it’s often used alone, pairing it with other plants is still possible. As it’s highly adaptable, it thrives equally well in partial shade or full sun.

In shady areas, you might consider pairing it in minimalist compositions, with horsetails, ferns, hostas, a carpet of Epimedium, and with helxine, a moss-like ground cover often used in Japanese-style gardens.

Pratia, Helxine, horsetail, and hostas

In sunny spots, for a wilder and more romantic style, place the Pratia near a natural planting of grasses, scabious, yarrow, sage, coneflowers, and a few clumps of Erigeron karvinskianus with its steely blue hues. It can also be used to carpet the base of softly coloured roses like the climbing ‘Iceberg’.

In containers, it will serve as a frame to highlight the fresh hues of spring bulbs like tulips.

Pratia angulata, climbing rose ‘Iceberg’, Erigeron karvinskianus, and scabious

→ Discover more ideas for pairing with Pratia in Virginie’s advice sheet!