Muehlenbeckia complexa aka Maidenhair Vine

Muehlenbeckia complexa is a vigorous climber that can reach 5 metres in height when given suitable support such as trellises, fences, or other plants to climb. As groundcover, it spreads to form dense mats up to 2 metres wide. The plant produces dense masses of slender, wiry, interlaced stems that create a tangled appearance, earning it names like 'wire vine' and 'mattress vine'. Growth rate is fast, with the plant capable of covering structures relatively quickly in favorable conditions.

Muehlenbeckia complexa thrives in temperatures between 18°C and 26°C when grown indoors. It is hardy to approximately -5°C but is sensitive to severe frosts. In the UK, it's hardy in southern and western regions but can be damaged or killed to ground level by harsh winter frosts. In USDA zones 7-10, it can be grown outdoors year-round, though in colder zones it may die back in winter and resprout from the roots in spring.

Muehlenbeckia complexa prefers medium to high humidity but is quite adaptable. In its native New Zealand habitat, it grows in coastal and forest environments with moderate humidity. Indoors, average household humidity is usually sufficient, though the plant appreciates occasional misting in dry conditions. If leaf edges become crispy, this may indicate the air is too dry.

Feed Muehlenbeckia complexa with a well-balanced organic fertilizer once a month during the active growing season from spring through summer. Reduce or stop fertilizing in autumn and winter when growth slows. The plant is not particularly demanding and will grow well even with minimal feeding, but regular fertilization promotes lusher, more vigorous growth.

Muehlenbeckia complexa can be propagated by seed or cuttings. Seeds should be sown in spring in a greenhouse. For vegetative propagation, take semi-hardwood cuttings in summer or hardwood cuttings of mature wood. Cuttings root readily and this is generally the preferred method as it produces plants faster than seed. Note that this species is dioecious, meaning you need both male and female plants to produce viable seed.

Muehlenbeckia complexa produces small, inconspicuous greenish-white flowers in autumn (August-September in the Southern Hemisphere). The flowers are not the main ornamental feature. The plant is dioecious, with separate male and female plants. On female plants, after pollination, the flower's perianth (outer covering) swells and becomes waxy white, enclosing a shiny black seed, creating an attractive fruiting display.

Muehlenbeckia complexa tolerates hard pruning and can be cut back as needed to control its vigorous growth. Prune in late winter or early spring before new growth begins. Regular trimming helps maintain a compact shape and prevents the plant from becoming too tangled or overwhelming its support structure. The wiry stems can be trimmed at any time to remove dead material or keep the plant tidy.

Repot Muehlenbeckia complexa every 1-2 years in spring, or when roots begin growing through drainage holes. Choose a pot only slightly larger than the current one, as the plant doesn't require excessive root space. Use a well-draining potting mix. This fast-growing vine can become rootbound relatively quickly, so check the roots annually and repot as needed to maintain healthy growth.

Muehlenbeckia complexa grows well outdoors in USDA zones 7-10 (UK zone 8). It's very salt and wind hardy, making it excellent for coastal gardens. Use it as ground cover, to clothe fences and trellises, or as a hedge plant. In colder regions, it may die back in winter but often resprouts from the roots. Protect from severe frosts, as temperatures below -5°C can cause significant damage.

Muehlenbeckia complexa is semi-deciduous to deciduous, losing most or all of its leaves in late autumn/early winter. During this dormant period, reduce watering and stop fertilizing. Leaves often turn bronze before dropping. In spring, resume regular watering and monthly feeding as new growth emerges. The plant is most actively growing in spring and summer when it requires consistent moisture and benefits from fertilization.

Yellow leaves on Muehlenbeckia complexa, especially on lower stems, typically indicate overwatering. While this plant likes moist soil, waterlogged conditions cause root problems. Ensure the pot has good drainage and allow the top layer of soil to dry slightly between waterings. Yellow leaves can also occur naturally in autumn as the plant prepares for its deciduous dormancy period.

Brown, crispy leaf edges and shriveled stems on Muehlenbeckia complexa usually indicate underwatering or low humidity. Check the soil—if it's dry, the plant needs more frequent watering. This vine prefers consistently moist soil and doesn't tolerate drying out completely. Increase humidity by misting or placing the pot on a pebble tray with water. Direct sunlight can also scorch the delicate foliage.

Drooping in Muehlenbeckia complexa is usually caused by underwatering—check if the soil is dry and water thoroughly if needed. The plant should recover within hours of watering. Overwatering can also cause drooping if roots become waterlogged and damaged, so check for soggy soil and reduce watering if this is the case. Ensure proper drainage in the pot.

Some leaf drop is natural for Muehlenbeckia complexa, which is semi-deciduous and loses most or all leaves in late autumn/winter. Bronze coloring before leaf drop is normal. Outside of autumn, excessive leaf drop may indicate stress from underwatering, overwatering, sudden temperature changes, or insufficient light. Ensure consistent care and appropriate growing conditions to minimize stress-related leaf loss.

Muehlenbeckia complexa is generally resistant to serious pests and diseases. Occasional issues may include spider mites in dry conditions, aphids on new growth, or mealybugs in the dense stem tangles. Good air circulation and appropriate humidity help prevent most problems. Root rot can occur in waterlogged soil—ensure proper drainage and avoid overwatering.

Yes, the fruit of Muehlenbeckia complexa is edible. The swollen, waxy white perianth that surrounds the black seed is sweet and juicy and can be eaten raw or cooked. PFAF rates its edibility as 3 out of 5. Note that only female plants produce fruit, and a male plant must be nearby for pollination. The fruit is also consumed by native New Zealand birds like tui, bellbird, and kererū.

Beyond its ornamental value, Muehlenbeckia complexa has several practical uses. It makes excellent ground cover and can be used as a hedge plant or windbreak due to its salt and wind hardiness—perfect for coastal gardens. It's useful for covering old tree stumps, rubble heaps, and unsightly structures. Ecologically, it provides habitat for insects and food for birds and butterflies, including being a host plant for New Zealand copper butterflies.

Muehlenbeckia complexa is dioecious, meaning individual plants are either male or female. Both sexes are required for pollination and seed production—a single plant will not produce viable seeds on its own. The small greenish-white flowers are pollinated by insects. The resulting fruit on female plants consists of a waxy white perianth enclosing a shiny black nutlet.