Garden flowers

Sweet pea

LathyrusFabaceae
Also: Lathyrus
AT A GLANCE
Full sun Water: lots H3down to −5 °C 1.5–2 m tall · 20–40 cm wide In a pot: yes
Flowering · UK
Flowering · Northern Italy
Flowering · Central Italy
Flowering · Southern Italy and islands

Autumn-sown plants overwintered in a cold frame flower earlier and stronger than spring sowings.

Care

Light

Full sun, with the roots kept cool.

Water

Medium-high — deep, regular watering in dry weather, or flowering stops and stems shorten.

Soil

Deep, fertile, moisture-retentive soil enriched with compost.

Pruning

Pick the flowers every few days: once pods form the plant stops flowering. Tie in stems to supports as they grow.

Feeding

Dig in compost before planting; then a high-potash liquid feed every two weeks once flowering begins. As a legume it needs little nitrogen.

Propagation

From seed — in autumn under cold cover for early, strong plants, or in late winter to early spring. Soaking or nicking hard seeds speeds germination; sow in deep pots or root trainers for the long roots.

Month by month

Months change with the climate: in southern Italy tomatoes go out two months earlier than in England.

  1. MarchPinch out the tips of young plants above the third or fourth pair of leaves. how ›
  2. AprilPlant out against canes, netting or an obelisk and tie in young stems. how ›
  3. JulyPick flowers every few days and remove any pods. how ›
  4. OctoberSow in deep pots for overwintering in a cold frame. how ›

Months based on climate: UK. Your choice stays on this device.

  1. MarchPinch out the tips of young plants above the third or fourth pair of leaves. how ›
  2. AprilPlant out against canes, netting or an obelisk and tie in young stems. how ›
  3. JulyPick flowers every few days and remove any pods. how ›
  4. OctoberSow in deep pots for overwintering in a cold frame. how ›

Months based on climate: Northern Italy. Your choice stays on this device.

  1. FebruaryPinch out the tips of young plants above the third or fourth pair of leaves. how ›
  2. MarchPlant out against canes, netting or an obelisk and tie in young stems. how ›
  3. JulyPick flowers every few days and remove any pods. how ›
  4. OctoberSow in deep pots for overwintering in a cold frame. how ›

Months based on climate: Central Italy. Your choice stays on this device.

  1. FebruaryPinch out the tips of young plants above the third or fourth pair of leaves. how ›
  2. MarchPlant out against canes, netting or an obelisk and tie in young stems. how ›
  3. JulyPick flowers every few days and remove any pods. how ›
  4. NovemberSow in deep pots for overwintering in a cold frame. how ›

Months based on climate: Southern Italy and islands. Your choice stays on this device.

Common problems

Flowering stops

How to spot it. Plants set pods and produce no new flowers.

What to do. Pick more often and never let pods ripen.

Powdery mildewfull sheet ›

How to spot it. White coating on leaves in late summer, usually when dry at the root.

What to do. Water deeply and mulch.

Mice and slugs

How to spot it. Seeds dug up; seedlings grazed.

What to do. Sow under cover and protect young plants.

Questions

Sweet pea: is it hardy?

H3: Half hardy. It survives down to −5 °C.

Can it grow in a pot?

Yes — dwarf types in pots; tall ones need a large, deep container and a tall support.

Sweet pea: when do you prune it?

Pick the flowers every few days: once pods form the plant stops flowering. In the calendar for UK, pruning falls in March.

Sweet pea: when does it flower?

In the climate of UK it flowers in June–September.

When do you feed it?

Dig in compost before planting; then a high-potash liquid feed every two weeks once flowering begins. As a legume it needs little nitrogen. Feeding months, UK: June–August.