GrowSabzHow to grow sweet pea in pots
Also called garden pea, flowering pea · Lathyrus odoratus
میٹھی مٹر
- ☀️ Sunlight
- 6–8hours daily
- 💧 Water
- 0.9 Levery 2 days, 10 L pot
- 🌡️ Ideal temp
- 13–24°C
- 🪴 Min pot
- 10 L25 cm deep
- 🧺 Harvest
- 60–75days from sowing
- ⚖️ Yield
- 1 kgper 20 L pot
Sweet Pea keeps producing once it starts. First picking comes around day 60, and the plant then crops for roughly 120 more days — but only if you keep picking. Blooms left on the plant is a signal to stop making more.
Short answer
Grow sweet pea in a 10 litre container at least 25 cm deep, watering about 700 ml per 10 litres of soil every 2 days, and keep temperatures between 13 and 24 °C. First harvest comes 60–75 days after sowing.
Where to plant it
What size pot does sweet pea need?
10 litres and 25 cm deep is the realistic minimum for a single plant. Pick a container below to see what changes.
| Container | Minimum size | Depth | Notes |
|---|---|---|---|
| Pot | 10 L | 25 cm | Ensure good drainage and provide support for climbing varieties. |
| Grow bag | 10 L | 25 cm | Fabric bags provide excellent aeration and drainage. Support is crucial for climbers. |
| Open ground | — | 30 cm | Plant in well-drained soil and provide ample space. Support climbing varieties. |
| Raised bed | 20 L | 30 cm | Excellent for drainage and soil control. Provide support for vining types. |
Watering
How often should you water sweet pea?
Every 2 days through the growing season, at about 700 ml per 10 litres of soil — daily in hot weather, every 3 days when it turns cool. Water in the early morning. Soaker hose or drip irrigation works best.
Too little water
- wilting
- stunted growth
- flower drop
- yellowing leaves
Too much water
- yellow lower leaves
- stunted growth
- root rot
Avoid: overhead watering; standing water; letting soil dry out completely.
Climate
Can you grow sweet pea where you live?
No hardiness zone needed — compare your actual temperatures against the plant's own limits.
| Ideal range | 13 – 24 °C |
|---|---|
| Survives | -5 – 28 °C |
| Germinates above | 10 °C — best at 18 °C, about 10 days |
| Flowers drop | above 27 °C, or below 5 °C |
| Sunlight | 6–10 hrs/day, best 8 |
| Frost | Medium sensitivity |
The flower-drop thresholds matter more than the survival ones. A plant can be perfectly alive at 28 °C and still give you nothing.
How cold is too cold for sweet pea? Check your temperaturesEnter your night low and day high — see if it survives, and if it will cropTimeline
Sweet Pea 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 sweet pea
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 sweet pea fails, and how to avoid it
- A container that is too small
Below 10 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. Sweet Pea wants about 700 ml per 10 litres of soil — one deep soak beats three shallow ones.
- Ignoring the flower-drop threshold
Above 27 °C, or below 5 °C, flowers fall before setting. The plant can look perfectly healthy and still give you nothing — shade it through the hottest hours.
- Planting it beside Onion
Can stunt the growth of sweet peas due to allelopathic effects or competition for nutrients.
Companions
What to plant with sweet pea
Good neighbours
Helps break up and aerate the soil, improving drainage and root access for sweet peas.
Deters nematodes and other soil-borne pests, promoting healthier root systems for sweet peas.
Can act as a trap crop for aphids, diverting them from sweet peas, or deter other pests.
Emits a scent that can deter aphids and other sucking insects from sweet pea plants.
Provides ground cover, keeping the soil cool and moist around sweet pea roots, which they prefer.
Keep apart from
Can stunt the growth of sweet peas due to allelopathic effects or competition for nutrients.
Competes for climbing space and can share similar pests and diseases, increasing risk for both.
Known to release substances that inhibit the growth of many plants, including sweet peas.
Close relatives like other sweet peas or edible peas will compete heavily for resources and are susceptible to the same pests and diseases.
Problems
Sweet Pea 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.
Aphids humidity any · temp 15-25
Small, soft-bodied insects that cluster on new growth and the undersides of leaves, sucking sap and causing distorted growth. Can transmit viruses.
Powdery Mildew humidity 50-70% · temp 20-27
White, powdery fungal spots appear mainly on the upper surface of leaves. Can stunt growth and reduce flowering.
Downy Mildew humidity >80% · temp 10-20
Causes yellow spots on the upper leaf surface and purplish-grey fuzzy growth on the undersides. Can lead to defoliation.
Slugs Snails humidity high · temp cool
Chew irregular holes in leaves, especially on young seedlings. Look for silvery slime trails.
Fusarium Wilt humidity any · temp warm soil
Causes yellowing and wilting of lower leaves, often affecting one side of the plant first. Soil-borne fungal disease.
Botrytis Blight humidity high · temp cool
Also known as grey mold. Causes fuzzy grey growth on flowers, buds, and leaves, leading to rot, especially in wet conditions.
Root Rot humidity any · temp any
Caused by overwatering or poor drainage. Symptoms include yellowing leaves, wilting, stunted growth, and soft, mushy roots.
Bud Drop Flower Drop humidity any · temp >25 or <10
Flower buds or open flowers fall off prematurely. Often caused by environmental stress such as extreme temperatures, inconsistent watering, or nutrient imbalance.
Harvest
When to harvest sweet pea
First picking falls between day 60 and day 75, and the plant then keeps producing for about 120 days. Pick often — what you leave on the plant signals it to stop making more.
How to tell it's ready
- Flowers are fully open or just about to open
- Stems are long and firm
How much to expect
Storing it: Place cut stems in water immediately. Store in a cool place, out of direct sunlight, for 5-7 days.
Questions
Sweet Pea: common questions
How long does sweet pea take to grow?
About 80 days from sowing to the first harvest, with picking usually starting between day 60 and day 75. It then keeps producing for roughly 120 more days. Warm weather pulls that forward; cool weather pushes it back.
What size pot does sweet pea need?
At least 10 litres and 25 cm deep for one plant. A raised bed wants 20 litres of soil and 30 cm of depth.
How often should I water sweet pea?
About 700 ml per 10 litres of soil, every 2 days in normal weather — daily when it is hot and every 3 days when cool. Water in the early morning.
What temperature does sweet pea need?
It does best between 13 °C and 24 °C and survives from -5 °C to 28 °C. Seed needs soil above 10 °C to germinate, ideally around 18 °C.
Can I grow sweet pea in winter?
It tolerates cold better than most, down to about -5 °C, so a sheltered spot or a cold frame will often carry it through.
How do I know when sweet pea is ready to harvest?
Flowers are fully open or just about to open; Stems are long and firm. Once picked: place cut stems in water immediately. store in a cool place, out of direct sunlight, for 5-7 days.
How much does one sweet pea plant produce?
Roughly 1 kg from a 20 litre container, or about 2 kg in open ground. Larger containers give proportionally more, up to a point.