Plectranthus ‘Magic Mona Purple’: the robust shade plant for autumn hanging baskets

Robust in shade, surprisingly late-flowering, and easy to manage.

Many people choose petunias or fuchsias, even though they demand considerable care. This South African perennial fills gaps as other plants fade, delivering a strong burst of colour in autumn.

Why gardeners want it now

The plant behind this insider favourite is Plectranthus ‘Magic Mona Purple’, often sold as ‘Mona Lavender’. Bred by De Wet Plant Breeders in South Africa, it belongs to the mint family. It develops into a compact, densely branched bush suited to pots and hanging baskets.

In a container, the plant grows to around 60 to 70 centimetres high and 60 to 75 centimetres wide. Rather than producing long trailing stems, it forms a dense, sturdy dome. Its leaf tops are deep green, while the undersides carry a purple sheen. This two-tone foliage noticeably brightens even shady corners.

Its greatest strength: purple flower spikes in autumn – precisely when many summer plants are giving up.

How it differs from petunias and fuchsias

This perennial provides structure rather than trailing growth. One plant will reliably fill a 25–30-centimetre hanging basket. It does not need daily deadheading, only an occasional trim. Bees and other pollinators consistently visit the flowers while temperatures remain mild.

Position and climate

A spot in bright shade or partial shade is ideal. The plant copes with morning sun, but midday heat on south-facing balconies puts it under stress. East- or north-facing positions work immediately, including beneath a lightly shaded tree canopy.

As a frost-sensitive perennial, it thrives year-round in USDA Zones 10–11. In central Europe, it should be grown in pots and moved outdoors after the last frosts. Before the first frost, bring it indoors promptly to a bright windowsill or conservatory.

As the thermometer approaches 0 °C, the plant should move indoors – helping it remain vigorous for years.

Planting and compost

A pot or basket with reliable drainage holes prevents waterlogging. The growing medium needs to be nutrient-rich, loose and permanently well aerated.

• Recommended mix per pot: 60% high-quality potting compost, 20% mature compost, 20% drainage material (perlite, pumice or fine expanded clay).
• For a 25–30-cm hanging basket, allow 5–7 litres of compost per plant.
• Water thoroughly after planting, then allow excess water to drain away.

Annual care calendar

Month	Task
March–April	Start young plants, root cuttings, and keep them somewhere bright and frost-free.
May	Move outdoors after the last frosts, first allowing plants to acclimatise in shade.
June–August	Water evenly, feed with liquid fertiliser every 14 days, and lightly pinch out the tips.
September–October	Main flowering period; remove spent blooms and bring plants in earlier when nights become cool.
November	Move indoors, check for pests, and trim back lightly.
December–February	Keep bright and cool (12–18 °C), water moderately, and do not feed.

Watering, feeding and pruning

Keep the compost consistently moist. Once the top two centimetres have dried out, water deeply until it runs from the base. Empty saucers after 10 minutes so that the roots can access air.

From May to September, apply a liquid fertiliser for flowering plants every 14 days. Alternatively, a moderately dosed controlled-release fertiliser applied in spring will work reliably for four to five months.

A light trim in spring encourages branching. It is also worthwhile removing flower stems after blooming. This helps the plant produce fresh shoots more quickly and retain its compact shape.

Water, yes; waterlogging, no: fresh compost encourages flowers, whereas wet roots hold the plant back.

Overwintering without fuss

Before cold weather arrives, inspect leaves and stem joints carefully for mealybugs or scale insects. Cutting the plant back by one third saves space and makes care easier. Indoors, Plectranthus prefers plenty of light at 12–18 °C.

Water sparingly through winter, but do not let the root ball dry out completely. Resume feeding only in spring. Turn the pot by a quarter every two weeks so the crown grows evenly.

Propagation is quick and reliable

Cuttings root dependably. Take non-flowering shoot tips measuring 8–10 centimetres. Remove the lower leaves, then place the stem bases into a 1:1 mix of perlite and seed compost.

At 20–22 °C in bright, indirect light, roots form within two to three weeks. A clear cover or freezer bag maintains high humidity. Air it briefly each day to prevent fungal growth.

Common problems and solutions

• Leaf scorch: avoid direct midday sun and choose a shadier position.
• Drooping shoots: check the compost and water thoroughly if it is dry.
• Yellow leaves despite moisture: improve pot drainage and, if necessary, switch to low-lime water.
• Root rot: eliminate waterlogging, remove affected parts, and use fresh compost.
• Spider mites/mealybugs in winter: rinse plants off early, then use yellow sticky traps and targeted oil-based sprays.

Design: hanging baskets that look good into autumn

‘Magic Mona Purple’ fills the centre as a structure-giving perennial. Trailing plants around the edge create soft transitions, while foliage plants reinforce the purple theme. Choose companions for partial shade with similar watering needs.

• Spillers: ivy (Hedera helix), creeping jenny (Lysimachia nummularia ‘Aurea’), and Dichondra ‘Silver Falls’ in lightly shaded settings.
• Fillers: coral bells (Heuchera), shade-loving begonias, and Carex ‘Evergold’ for fine grassy texture.
• Accents: white or lavender lobelia in cooler, partially shaded areas.

A recipe for sturdy hanging baskets: 1 perennial in the centre, 2 fillers beside it, 3 spillers at the edge – and the autumn display is complete.

Useful facts: names, origin and hardiness

Both names appear in the trade: ‘Magic Mona Purple’ and ‘Mona Lavender’. Each refers to this compact, autumn-flowering Plectranthus range. The species originates in South Africa, where frost-free winters are common. In the UK, it therefore works as a perennial container plant with an indoor winter rest period.

Two further practical details

Explanation of the term: USDA zones describe average annual minimum temperatures. Zone 10 begins at around –1 °C, while Zone 11 is above +4 °C. Anyone gardening in colder areas should use containers and bring plants indoors in good time.

Example calculation for a 30-cm hanging basket: 7 litres of compost, 1 main Plectranthus plant, 2 companion plants and 3 spillers. On warm days, water requirements are around 1–1.5 litres per watering. Half a teaspoon of liquid fertiliser per 5 litres of watering water every two weeks is enough to maintain rich colour over time.