Lablab purpureus
Hyacinth bean
Common names: Lablab bean, Indian bean
At a glance
- Light
- Full sun
- Spacing
- 40 cm, rows 80 cm
- Lifespan
- Annual
- Sowing
- May
- Harvest
- Aug–Oct
- Hardiness
- Cold damage below 2 °C
- Water need
- Medium
Photo: Aris riyanto · CC BY-SA 4.0 · Source
Description
The hyacinth bean, botanically Lablab purpureus, is a vigorous climbing ornamental bean with violet flowers and glossy, often purple pods. It originates from warmer regions and requires a sunny, sheltered spot and a sturdy trellis of at least 2 m in height. The young, tender pods can be prepared like bush beans; the mature seeds and older pods are raw toxic and should only be eaten after thorough cooking. Keep raw seeds and hard pods out of reach of children and pets.
Care instructions
Sow the hyacinth bean after the last frost, around mid‑May (week 20), directly in the garden or start indoors in warm conditions from April. The soil should be loose, nutrient‑rich, and kept evenly moist; the plant does not tolerate waterlogging. Provide a firm trellis early on so the plant climbs quickly and flowers into autumn. Harvest young pods continuously to encourage further flowering, and protect the plant at cool nights with a cloth, as it is damaged at temperatures below 2 °C.
The care notes were machine-translated from German.
Garden year
SowingMay
HarvestAug–Oct
Germination
- Soil temperature
- from 15 °C, ideally 25 °C
- Days to sprout
- 7 to 14 days
- Light
- Sprouts in light or dark
- Sowing depth
- 3 cm
- How to start
- Start indoors, then plant out
Soil & site
Soil pH
Soil type
well-drained, nutrient-rich, humus-rich, loamy
The hyacinth bean likes loose, humus-rich soil that holds moisture without becoming waterlogged. A sunny, warm spot with nutrient-rich ground makes the vines grow strongly. It is best to loosen heavy, compacted soils with mature compost before planting.
As a legume, the hyacinth bean improves the soil for following crops and should only stand in the same place again after a break of four years.
Feeding
Medium feeder
Months
May–Jul
At planting, work mature compost or well-rotted manure into the bed; that is enough for a good start. During the main growing season from May to July, the hyacinth bean welcomes a dose of organic vegetable fertiliser or nettle liquid feed every three to four weeks. As a legume it fixes nitrogen from the air itself, so moderate feeding is quite enough.
Overwintering
In our latitudes the hyacinth bean is an annual and does not survive frost. The plants die off with the first cool nights in autumn and are cleared away. If you want to keep the variety, collect ripe seeds before the first frost and store them dry for the next sowing.
Propagation
Methods
- From seed
Propagation is exclusively by seed. From mid May · week 20, when there is no longer any danger of frost, you sow directly into the open ground, or raise the plants on a windowsill from April. The seeds germinate reliably at warm temperatures of around 20 degrees; soaking overnight speeds up germination. Plants raised in advance go into the bed after the Ice Saints; tied to a climbing frame, they quickly grow upwards.
Companion planting
Good neighbors
cabbage family (Brassicaceae)
particularly well establishedLeguminous plants collect nitrogen in the soil, from which Brassicaceae benefit as heavy feeders.
For example White cabbageKohlrabiRadishKalebroccolicauliflower and 41 more species in the catalogue
Source: classic companion planting (DACH-Gartenpraxis)
carrot family (Apiaceae)
Peas and beans provide carrot and celery with nitrogen and grow as shallow-rooted plants without competition next to each other.
For example CarrotCeleriacDillParsleyFlorence fennelCoriander and 21 more species in the catalogue
Source: classic companion planting (DACH-Gartenpraxis)
Rather not
amaryllis family (Amaryllidaceae)
particularly well establishedAllium species inhibit the nitrogen‑fixing rhizobia of legumes through their root exudates, which slows their growth.
For example GarlicOnionLeekChivesWild daffodilRocambole and 12 more species in the catalogue
Source: basic crop‑rotation rule
Companion planting is partly traditional gardening lore. Where the reason is known, it is given.
Some of these explanations were machine-translated.
For your garden
Grow Hyacinth bean yourself
Gartenkern tells you when frost is coming, when to sow and when to harvest, for your location.
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