Cupani (Lathyrus odoratus 'Cupani') - purple flowers, illustrated plant cardIllustration

Cupani

Lathyrus odoratus 'Cupani'

Cupani blooms from May through July.

Bloom calendar
Bloom time
May–Jul
not yet checked
Hardiness
Zones 2–11
not yet checked
Sun
Full sun
not yet checked
Water
Moderate water
not yet checked
Mature size
6 ft × 1.5 ft
not yet checked
Type
Annual
house classification

Months here are Northern Hemisphere months; in the Southern Hemisphere, shift them by six months.

Growing Cupani

Plant it in full sun. It prefers moderate water. It is hardy in USDA zones 2–11. Expect it to reach about 6 ft tall and 1.5 ft wide at maturity, in roughly 1 year (not yet checked).

Verification
What this means

Written with AI assistance and not yet checked plant by plant against recorded sources, so treat every fact above as a starting point. Its scientific name was checked against botanical registries, an audit keeps its values consistent with the rest of the library, and a July 2026 review re-read the main facts of every plant then in the library against horticultural authorities without recording a source for each, which is why none of that counts as checked here. The source-by-source check is working through the whole library in the open, and a checked plant says so in this row.

When to plant Cupani

Wait until all danger of frost has passed, then plant out Cupani into warm soil; in most zones that means late spring. Planted then, it flowers from May to July.

Month-by-month timing for your zone is on the planting calendar; if you garden near zone 6, the middle of this plant's hardy range, start with zone 6 in April. Derived from the plant's category, zones and bloom months plus typical zone frost dates, not checked separately.

How big does Cupani get?

Illustration of Cupani drawn to scale beside an adult6 fttall5 ft 7 inan adult1.5 ftwide
About 6 ft tall and 1.5 ft wide at maturity: about as tall as an adult.

See Cupani in a garden plan: the planner shows it in 3D beside everything else you add, growing toward this size over the years.

How far apart to plant Cupani

Derived from the mature spread above by a fixed rule, not checked separately: spacing is the spread, center to center.

Space Cupani about 1.5 ft apart, center to center, so each plant has room to reach its full width.

Plant them
1.5 ft apart
Per 10 sq ft
about 4
4 by 8 ft bed
about 10

Add Cupani to a garden plan and the planner draws it at its full width, so you see the spacing before you buy.

Good to know about Cupani

Curated from university extensions, botanic gardens and other primary sources, with the source named on every note.

Safety

The seeds and pods are poisonous: do not eat them, and do not confuse this with the edible garden pea it resembles. Keep seeds from children and pets. per NC State and Missouri Botanical Garden

The Sweet Pea group

One of 6 in the Sweet Pea group. Same plant, same care.

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Design a garden with this

Drop this plant onto a 3D plan, see how it fills in, and watch your whole garden bloom across the year.

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