Alternanthera ‘Little Ruby’

Alternanthera 'Little Ruby' (Alternanthera dentata 'Little Ruby') is the deep burgundy groundcover that gives a garden bed permanent colour without a single flower doing the work. It stays low, around 40cm tall and spreading to about 80cm, and it fills space fast. Planted 40cm apart it closes into a continuous ruby carpet within a season, which is why landscapers reach for it whenever a bed needs contrast against green foliage or pale paving.

Why you'll love it

• Colour that never stops. Deep burgundy leaves with a wine red underside, holding through the year in warm gardens. The flowers are tiny, so nothing goes off colour after a flush.
• It fills space quickly. Fast growing and low maintenance, so a bed planted from tubes covers over in one warm season rather than three.
• Tough in the heat. Heat, humidity and drought tolerant once established, which covers most of the hard positions in a northern garden.
• Easy to renew. Cut it back hard in early spring and it reshoots dense and low, undoing a season of legginess in one afternoon.

Where it works best

Groundcover and mass planting. Plant 40cm apart for a dense groundcover. At that spacing the plants knit into an unbroken sheet in a single warm season, and weeds struggle for light underneath.

Borders and edging. A single row at 40cm spacing gives a clean dark line along a path, reading well against concrete and lawn.

Pots and containers. In cool southern gardens a pot is the practical answer, since it can be moved under cover when frost threatens.

Growing Little Ruby in Australia

Position and climate. Full sun gives the deepest colour; in part shade the burgundy dulls towards green. This is a tropical, subtropical and warm temperate plant, and it is frost tender. A hard frost knocks it back and a run of them will kill it.

Soil. Free draining soil of almost any type. Work compost through the bed first, since a fast groundcover asks a lot of the top 100mm of soil.

Water and feed. Water two or three times a week for the first six weeks while the roots take, then taper off. Established plants tolerate dry spells, though density is better with regular summer water. Slow release fertiliser in early spring and midsummer keeps growth pushing.

Pruning. Cut back hard in early spring, to about a third of its height. Plants left uncut for two or three years go woody and open in the middle.

What to expect when it arrives

Little Ruby is supplied as tube stock, which is the right size for this plant. Tubes are small, usually a single rooted cutting, and they establish fast enough that larger pots rarely pay for a groundcover. For a 4 square metre bed at 40cm spacing you need about 25 tubes.

Tubes travel well because there is little top growth to damage. Plant them out within a few days of delivery and expect visible spread within four to six weeks in warm weather, with full coverage over one growing season. Plants are delivered Australia wide, with delivery from $29.95 and a minimum order of $300 before delivery. Every plant is covered by our 30 day healthy plant guarantee.

Plant care guides and related reading

• Choosing the right groundcover for your garden
• Browse the full groundcover range
• Plants suited to mass planting
• Plants that perform in containers

Common questions

How many plants do I need per square metre?

At 40cm spacing you need roughly six plants per square metre. Tighter spacing does not speed up coverage meaningfully, and it makes the bed harder to water evenly while the plants are young.

Will it survive frost?

No. Little Ruby is frost tender and will be damaged by even a light frost, with hard frosts killing it outright. In cool temperate and frosty inland gardens, grow it in a pot that can be moved under cover.

Why has my plant gone green?

Not enough light. The burgundy pigment develops in strong sun, so plants in shade or under a dense canopy drift towards dull green. Move it somewhere sunnier and the colour returns with the next flush.