Ivy-leaved toadflax

How to recognise it

Habit

Creeping and trailing perennial with thin, often purplish stems 10–60 cm long that root at the nodes. Forms loose mats and curtains no more than 5 cm thick.

Leaf

Round to kidney-shaped, 1–3 cm across, with 5–7 shallow, rounded lobes, like a miniature ivy leaf. Hairless and slightly fleshy, often purple underneath, on long stalks.

Flower

Small snapdragon-like flowers about 1 cm long, lilac to pale violet with a short spur, on long stalks from the leaf axils. Two yellow bumps at the mouth.

Fruit/Seed

A small round capsule with tiny wrinkled seeds. After flowering the stalk bends towards the wall and pushes the capsule into a crevice.

Roots

Thin, fibrous roots that wedge themselves into joints and cracks; the stems also root wherever they touch the ground or the wall.

Look-alikes

Ground-ivy also has round leaves, but they are scalloped and opposite on a square, aromatic stem, and the flowers are blue-violet and two-lipped. Young ivy has larger, leathery, glossy leaves and no flowers.

Flowering: April–October

Why grow it?

• Flowers for months, from April to October, and often later still in a mild autumn.
• Brings life to bare walls, steps, retaining walls and the gaps between stones, where hardly anything else grows.
• The little flowers are visited by bumblebees and small wild bees.
• Grows in sun and shade, in dry spots, with almost no soil and no care.
• A fascinating plant for children: after flowering, the flower stalks turn away from the light and plant the seed in the wall themselves.

Ivy-leaved toadflax: where does it grow best?

• In the wild: old walls with lime mortar, quaysides, bridges, rocks and rubble, especially in towns, villages and along rivers.
• Sun to shade: on a north-facing wall it stays fresh green; in full sun it flowers more but stays smaller.
• Needs almost no soil: a joint with a little lime mortar, sand or dust is enough.
• In the garden: dry-stone walls, a rock garden, the edge of a raised bed, between steps or in a hanging basket.
• Preferably limy and free-draining; it dislikes heavy, waterlogged soil.

Goes well with

• Maidenhair spleenwort: A small evergreen fern that grows in the same wall joints.
• Wall-rue: A classic little fern of lime-mortared walls, with grey-green fronds.
• Yellow corydalis: Flowers just as long, in yellow, and also seeds itself into walls.
• Biting stonecrop: Yellow stars in June for the sunniest, driest parts of the wall.
• Herb-Robert: Pink flowers and red leaves on the shady side of the wall.

Ivy-leaved toadflax: when and how to plant it?

1. Buy a plant from a nursery specialising in native or alpine plants, or ask for a piece from someone who has it on their wall. Never dig plants up from the wild.
2. Plant in April–May or in September, when the wall is neither too hot nor too dry.
3. Push a small root ball into a joint or crevice with a little sandy loam or potting compost, and wedge it in with a small stone or some moss.
4. You can also sow: in spring, mix the fine seed with a little damp loam and press the little ball into a joint.
5. Space plants 30–40 cm apart; they soon grow together.
6. Keep the joint moist for the first few weeks with a mister or a fine-rosed watering can, until the plant has taken hold.

Care

Water

Not needed once established. In a hot summer it may wilt, but it recovers after rain.

Feeding

Don’t: on a poor wall it stays compact and flowers best.

Spreading

If it gets too exuberant, simply pull off a few trails. The roots are shallow and come away easily.

Self-seeding

Leave the capsules: that way it seeds itself into new crevices and the wall stays covered, even if an old plant dies.

Walls

It does little harm to sound walls. In crumbling lime joints the roots can loosen the mortar a little; remove it where you repoint.

Tip: Want to green a bare wall quickly? Mix a pinch of seed with a handful of damp loam, roll it into little balls and press them into the joints: the seed stays put and germinates in the cracks.

Pruning and mowing

When: No pruning needed. You can thin it out whenever you like, preferably in spring.

How:

• Pull off over-long or bare trails, or cut them off at the base.
• In spring, after a hard winter, remove dead brown stems.
• Always leave some plants so that it can seed itself again.

Pruning calendar and basic rules

Propagation

Seed

Seeds itself into crevices. To sow it yourself, in April–May: barely cover the seed, if at all, and keep it moist. It usually germinates readily.

Division

In spring or early autumn, detach stems that have already rooted at the nodes and push them into another joint.

Cuttings

In summer, pieces of stem 5–10 cm long root easily in damp sand.

Ivy-leaved toadflax: how does it get through the winter?

Hardy to −20 °C.

• In mild winters it stays green and sometimes still flowers in November or December.
• In hard frost the top growth dies back, but it shoots again in spring from the roots or from seed.
• Hardy to about −20 °C; in a dry wall joint it survives frost better than in wet soil.

Diseases and pests

• Drying out: In a hot summer it hangs limp in full sun. No matter: it recovers after rain. On a south-facing wall it picks the cooler joints by itself.
• Too many seedlings: Sometimes turns up in the vegetable garden or between paving stones. Pull them out: they come away easily.
• Slugs: May nibble the leaves on a damp, shady wall. The plant usually recovers by itself.
• Loose joints: On an old wall with crumbling lime mortar, the roots can loosen the joints further. Repair the joint and let the plant grow elsewhere.

Through the year

• March: New shoots. Remove dead stems after winter.
• April: First flowers. Plant or sow in joints.
• May: Full flower. Bumblebees and small bees visit the flowers.
• June: Flowering. The first fruit stalks bend towards the wall.
• July: Flowering. In full sun it may wilt in dry weather.
• August: Flowering and setting seed. Take cuttings.
• September: Still in flower. Seedlings appear in new crevices. You can still plant.
• October: Last flowers. Pull off over-long trails.
• December: Stays green in mild winters.

Did you know?

• After flowering, the fruit stalks turn away from the light, towards the dark wall. In this way the plant pushes its own seed into a crevice where it can germinate.
• The scientific name Cymbalaria comes from the Greek kymbalon, cymbal, after the round leaves; muralis means ‘of walls’.
• It is related to foxglove and the plantains: once placed in the figwort family, it now belongs to the plantain family.