How big does Hardy plumbago grow?

About 25 cm × 50 cm after ten years (height × width). Its ultimate size is 15–30 cm × 30–50 cm.

What soil does Hardy plumbago grow in?

It tolerates these soils: average garden soil, clay, sandy, calcareous.

Is Hardy plumbago hardy?

Hardy down to -23 °C (USDA zone 6, RHS H7). It gets through winter everywhere at lower altitudes, but may not survive unprotected in a mountain garden.

Is Hardy plumbago toxic to dogs?

No. Reliable sources list it as non-toxic to dogs.

Is Hardy plumbago toxic to cats?

No. Reliable sources list it as non-toxic to cats.

Is Hardy plumbago toxic to children?

Yes, it is mildly toxic to children.

When does Hardy plumbago flower?

Flowering: July–October, blue.

How much water does Hardy plumbago need?

Water need: low. Drought tolerance: high.

Hardy plumbago

Ceratostigma plumbaginoides

Hardy plumbago (Ceratostigma plumbaginoides) is a ground cover plant that reaches 25 cm × 50 cm after ten years. Light: full sun, part shade. Hardy down to -23 °C. Drought tolerance: high. Non-toxic to dogs and cats, mildly toxic to children. Sold in local shops from about €5.

Illustration of Hardy plumbago — An illustration of the typical shape of the mature plant, not a photo.

What it's good for, and what it isn't

A low perennial spreading by rhizomes that carries gentian-blue flowers from late summer until the frosts while its leaves turn bronze-red. It makes a good ground cover in sun or part shade under shrubs or among early bulbs, because it comes up very late in spring, so do not assume it has died. It spreads strongly and crowds out weaker neighbours, so give it a spot where that does no harm.

Watch out for

In Central Europe it can be lost in very cold, wet winters, above all in heavy, wet soil: plant it in well-drained ground and give it a leaf mulch in harsher areas. Because it emerges late, its patch stays bare for a long time in spring. In good conditions its spread is hard to contain, and powdery mildew turns up occasionally.

Key facts

Light: Full sun, Part shade
Water need: Low
Care: Low
Size after 10 years: 25 cm × 50 cm
Hardiness: down to -23 °C
Foliage: Deciduous
Flowering: J F M A M J J A S O N D July–October, blue

Group	Ground cover
Light	Full sun, Part shade
Size after 10 years	25 cm × 50 cm
Ultimate size	15–30 cm × 30–50 cm
Hardiness	down to -23 °C (USDA 6, RHS H7)
Soil	Average garden soil, Clay, Sandy, Calcareous
Foliage	Deciduous
Flowering	July–October, blue
Water need	Low
Drought tolerance	High
Maintenance	Low
Root aggressiveness	Low
Suckering	no data
Spreading	High
Distance from buildings	no data
Distance from paving	no data
Litter	not typical
Planting distance	30 cm
For dogs	Non-toxic
For cats	Non-toxic
For children	Mildly toxic
Typical price	from about €5

Toxicity data is for information only. If your pet or child has eaten a plant, contact a vet or a doctor.

Sizes and prices available

The same plant is sold as a small pot and as a specimen several metres tall, and the price follows. Prices are rounded and for guidance only.

Size	Typical price
10-15 cm	approx. €5

Frequently asked questions

Data updated: October 8, 2026 · How our data is made

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Ground cover plants Drought-tolerant plants Drought-tolerant plants for sandy soil Plants that are non-toxic to dogs Plants that are non-toxic to cats Plants for containers Rock garden plants Plants with autumn colour

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