How to grow Lablab in Australia
Lablab, or hyacinth bean, is a vigorous climbing legume with purple or white flowers and flat pods, grown in warm areas as an ornamental screen, a soil-improving green manure and, with care, a vegetable. It handles heat and dry spells better than common beans. The mature beans and pods must be boiled well in several changes of water before eating, as they are toxic raw.
📖 Our full guide: How to Grow Lablab in Australia
At a glance
When to sow by region
| Region | When to sow | Regional note |
|---|---|---|
| South East Queensland | October to January | |
| Northern Rivers NSW | October to January | |
| Sydney & Coastal NSW | October to January | |
| Melbourne & Victoria | Not suited | Not viable in Melbourne. Needs tropical warmth. |
| Adelaide & SA | November and December | Sow Nov to Dec once soil passes 20C. Handles heat and dry better than common beans; frost kills it in autumn. |
| Perth & WA | October to January | |
| Tasmania | Not suited | Unsuitable. Needs tropical warmth. Not viable in Tasmania. |
| Canberra & ACT | Not suited | Not viable in Canberra. Needs tropical warmth. |
| North Queensland | September to March | Year-round in tropics. Vigorous growth. |
| Darwin & Top End | All year | Year-round in Darwin. Major tropical legume. |
Not to be confused with: Beans, the common climbing and bush beans, which are grown and eaten differently, and Cowpea, another heat-tolerant tropical legume.
Where to plant
Grow lablab in full sun in well-drained soil, with a sturdy trellis, fence or arbour for it to climb. It grows in average daily temperatures of about 18 to 30°C. Seedlings grow slowly at first, but once established the vine competes well with weeds and tolerates drought and some shade.
As a legume, lablab fixes nitrogen and improves the soil, so it is also grown as a summer green manure or cover crop in warm areas, then dug in or slashed before it sets seed.
- North Queensland and Darwin: grows all year and vigorously. In North Queensland sow from September to March; in Darwin, any month.
- South East Queensland, the Northern Rivers, Sydney and Perth: sow from October to January once the soil is warm.
- Adelaide: sow in November and December once the soil passes about 20°C. It handles heat and dry better than common beans; frost kills it in autumn.
- Melbourne, Canberra and Hobart: our calendar marks these as unsuitable, as lablab needs tropical warmth.
Choosing a variety
Ornamental and edible types are both sold. Ruby Moon has purple flowers and glossy purple pods and is grown mainly as an ornamental climber. Forage cultivars such as Rongai are sold for livestock feed and green manure. Varieties differ widely in their levels of natural toxins.
How to plant
- Put up a strong trellis or fence before sowing.
- Wait until the soil is warm, above about 20°C.
- Sow seed direct about 2 to 3 cm deep and about 30 cm apart along the support.
- Water once after sowing, then keep the soil just moist until seedlings appear.
- Pinch the growing tips once the vines are established to encourage branching.
Watering and feeding
Water regularly while plants are young. Once established, lablab tolerates dry spells well, though regular watering through flowering gives more pods.
As a legume it makes much of its own nitrogen, so it needs little feeding. Avoid high-nitrogen fertilisers.
Harvesting
Pick young, tender pods before the beans inside swell, usually from about ten weeks after sowing, and keep picking to encourage more. Mature, dry beans can be saved for seed.
Never eat lablab pods or beans raw or lightly cooked. They contain cyanogenic glycosides, which release cyanide, and levels vary widely between varieties. They are edible only if boiled well with several changes of water. If you are unsure of your variety, grow it as an ornamental or green manure rather than for food.
Growing in pots
Lablab can be grown in a pot at least 30 cm wide and deep with a trellis or obelisk, which makes an attractive flowering screen on a balcony. Water regularly in summer.
Using it
Lablab is widely eaten in Asia and Africa, but always after thorough boiling in several changes of water. In Australian gardens it is grown more often for its flowers and purple pods, as a quick summer screen, or as a green manure to improve the soil.
Companion planting
Lablab is a vigorous climber that adds nitrogen to the soil, so it suits the edge of a summer bed.
Good companions
Pests and diseases
Lablab shares the pests of other warm-season beans.
Pests to watch for
- Bean fly Young plants wilt and collapse, with swollen stems near the soil where maggots tunnel. Worst in warm, humid areas.
- Caterpillars Holes bored into the pods and seeds eaten, mostly by pod borer caterpillars. Check pods and pick caterpillars off.
- Aphids Clusters of small dark insects on shoot tips and flower stems.
Lablab is rarely troubled by disease.
Common questions
Is lablab poisonous?
The pods and beans contain cyanogenic glycosides, which release cyanide, and are toxic raw or undercooked. They are only edible after boiling well in several changes of water, and levels vary between varieties. If unsure, grow it as an ornamental or green manure.
Can I use lablab as a green manure?
Yes. Lablab is a legume that fixes nitrogen and grows a lot of leaf in summer. Slash or dig it in before it sets seed to improve the soil for the next crop.
When should I plant lablab?
Once the soil is warm, above about 20°C: October to January in south east Queensland, Sydney and Perth, November and December in Adelaide, and all year in the tropics.
Is lablab drought tolerant?
Once established, yes. It handles heat and dry spells better than common beans, though young plants need regular water.
How fast does lablab grow?
Seedlings start slowly, then the vine grows quickly in warm weather, climbing 2 to 5 m in a season. Give it a strong support.
What is Ruby Moon lablab?
An ornamental variety with purple flowers and glossy purple pods, grown mainly as a fast summer climber and screen.
Sources we checked: Wikipedia: Lablab.