GrowSabzHow to grow soybean in pots
Also called Soya bean, soya, soyabean, soja · Glycine max
سویابین
- ☀️ Sunlight
- 6–8hours daily
- 💧 Water
- 1.3 Levery 3 days, 15 L pot
- 🌡️ Ideal temp
- 20–30°C
- 🪴 Min pot
- 15 L30 cm deep
- 🧺 Harvest
- 60–75days from sowing
- ⚖️ Yield
- 1.5 kgper 20 L pot
Soybean is a heat-lover with no tolerance for cold. It wants 20–30 °C and frost kills it outright. Everything about growing it well comes down to timing — getting it into the season early enough to crop before temperatures fall away.
Short answer
Grow soybean in a 15 litre container at least 30 cm deep, watering about 700 ml per 10 litres of soil every 3 days, and keep temperatures between 20 and 30 °C. First harvest comes 60–75 days after sowing.
Where to plant it
What size pot does soybean need?
15 litres and 30 cm deep is the realistic minimum for a single plant. Pick a container below to see what changes.
| Container | Minimum size | Depth | Notes |
|---|---|---|---|
| Pot | 15 L | 30 cm | Use large pots with good drainage for a few plants. |
| Grow bag | 15 L | 30 cm | Fabric bags provide good aeration for roots. |
| Open ground | — | 30 cm | Ensure well-drained soil and proper spacing. |
| Raised bed | 20 L | 30 cm | Excellent for controlling soil conditions and drainage. |
Watering
How often should you water soybean?
Every 3 days through the growing season, at about 700 ml per 10 litres of soil — every 2 days in hot weather, every 4 days when it turns cool. Water in the early morning. Drip irrigation or furrow irrigation works best.
Too little water
- wilting leaves
- leaf curling
- reduced pod set
- smaller beans
Too much water
- yellowing leaves
- stunted growth
- root rot
- fungal diseases
Avoid: waterlogging; overhead watering during flowering; shallow frequent watering.
Climate
Can you grow soybean where you live?
No hardiness zone needed — compare your actual temperatures against the plant's own limits.
| Ideal range | 20 – 30 °C |
|---|---|
| Survives | 5 – 35 °C |
| Germinates above | 10 °C — best at 25 °C, about 7 days |
| Flowers drop | above 35 °C, or below 15 °C |
| Sunlight | 6–10 hrs/day, best 8 |
| Frost | Highly sensitive — will not survive it |
The flower-drop thresholds matter more than the survival ones. A plant can be perfectly alive at 35 °C and still give you nothing.
How cold is too cold for soybean? Check your temperaturesEnter your night low and day high — see if it survives, and if it will cropTimeline
Soybean growing stages, day by day
Click any stage to see what's happening. Durations shift with temperature — a warm season runs roughly a quarter faster than a cool one.
Feeding
Fertiliser schedule for soybean
Feed on the interval below, changing what you give as the plant shifts from making leaves to making fruit.
| Stage | What to use | Per 10 L | Every |
|---|
How to prepare each feed
Common mistakes
Why soybean fails, and how to avoid it
- A container that is too small
Below 15 litres the root run is too shallow. The plant grows, flowers late, and drops whatever it sets because it cannot support the crop.
- Watering too lightly
A daily splash wets the top few centimetres and nothing else. Soybean wants about 700 ml per 10 litres of soil — one deep soak beats three shallow ones.
- Ignoring the flower-drop threshold
Above 35 °C, or below 15 °C, flowers fall before setting. The plant can look perfectly healthy and still give you nothing — shade it through the hottest hours.
- Harvesting too late
Left too long the colour changes, seeds harden and the flavour sharpens. Pick on the signs listed below, not on the calendar.
- Planting it beside Onions
Onions and other alliums can inhibit the growth of soybeans and may attract similar pests.
- Leaving it out through a cold snap
Soybean is highly frost-sensitive. One night below 5 °C can end the plant outright — bring containers in or cover them.
Companions
What to plant with soybean
Good neighbours
Soybeans fix nitrogen, benefiting corn. Corn provides a natural trellis for climbing soybean varieties.
Potatoes benefit from the nitrogen fixed by soybeans, improving their growth and yield.
Cucumbers benefit from the nitrogen fixed by soybeans, promoting healthier vine growth.
Marigolds repel nematodes and other harmful soil pests that can affect soybean roots.
Rosemary's strong scent can help deter bean beetles and other insect pests from soybeans.
Keep apart from
Onions and other alliums can inhibit the growth of soybeans and may attract similar pests.
Garlic, like onions, can stunt soybean growth and compete for soil nutrients.
Members of the Brassica family (cabbage, broccoli, kale) can stunt soybean growth due to competition for nutrients.
Fennel produces substances that can inhibit the growth of many plants, including soybeans.
Both peas and soybeans are legumes and can compete for similar soil resources and attract similar pests and diseases.
Problems
Soybean pests and diseases
Each lists the weather that brings it on, so you know when to start checking rather than reacting once it's established.
Soybean Aphids humidity any · temp 15-25
Small, soft-bodied insects that cluster on new growth and undersides of leaves, sucking sap and transmitting viruses. Can cause stunted growth and reduced yield.
Bean Leaf Beetles humidity any · temp 20-30
Small beetles that feed on leaves, creating circular holes. They can also feed on pods, causing damage and reducing marketability.
Spider Mites humidity <50% · temp >27
Tiny pests that cause leaves to look stippled, pale, and eventually turn yellow and drop. Fine webbing may be visible on the undersides of leaves, especially in hot, dry conditions.
Soybean Cyst Nematode humidity any · temp any
Microscopic worms that infect soybean roots, causing stunted growth, yellowing, and reduced yield. Small white to yellow cysts may be visible on roots.
White Mold humidity >80% · temp 15-25
Also known as Sclerotinia Stem Rot. Causes white, cottony fungal growth on stems and pods, leading to wilting and plant death. Black, hard sclerotia may form.
Bacterial Blight humidity >85% · temp 20-28
Causes small, angular, water-soaked spots on leaves that turn brown with a yellow halo. Can lead to defoliation and reduced photosynthesis.
Soybean Rust humidity >70% · temp 20-30
Appears as small, reddish-brown pustules on the undersides of leaves. Can cause premature defoliation, leading to significant yield loss.
Sudden Death Syndrome humidity any · temp cool, wet early season followed by warm, dry
Causes interveinal chlorosis (yellowing between veins) and necrosis (tissue death) on leaves, while leaf veins remain green. Leaves drop, but petioles remain attached. Often accompanied by root rot.
Harvest
When to harvest soybean
First picking falls between day 60 and day 75, and the plant then keeps producing for about 20 days. Pick often — what you leave on the plant signals it to stop making more.
How to tell it's ready
- Pods are plump and bright green
- Beans inside pods are well-formed
- Pods are still tender, not tough or yellowing
How much to expect
Storing it: Refrigerate fresh pods for up to a week. For longer storage, blanch and freeze.
Questions
Soybean: common questions
How long does soybean take to grow?
About 120 days from sowing to the first harvest, with picking usually starting between day 60 and day 75. It then keeps producing for roughly 20 more days. Warm weather pulls that forward; cool weather pushes it back.
What size pot does soybean need?
At least 15 litres and 30 cm deep for one plant. A raised bed wants 20 litres of soil and 30 cm of depth.
How often should I water soybean?
About 700 ml per 10 litres of soil, every 3 days in normal weather — every 2 days when it is hot and every 4 days when cool. Water in the early morning.
What temperature does soybean need?
It does best between 20 °C and 30 °C and survives from 5 °C to 35 °C. Seed needs soil above 10 °C to germinate, ideally around 25 °C.
Can I grow soybean in winter?
Not outdoors anywhere that frosts — it is highly frost-sensitive and will not survive it. In a frost-free winter it grows slowly; anywhere colder, treat it as a warm-season crop.
How do I know when soybean is ready to harvest?
Pods are plump and bright green; Beans inside pods are well-formed; Pods are still tender, not tough or yellowing. Once picked: refrigerate fresh pods for up to a week. for longer storage, blanch and freeze.
How much does one soybean plant produce?
Roughly 1.5 kg from a 20 litre container, or about 3 kg in open ground. Larger containers give proportionally more, up to a point.