Few herbs truly astonish; this one does. Giant lettuce-leaved basil ‘Napoletano’ grows leaves of a size that seems almost impossible for basil: broad, tender and generous, each one many times larger than the familiar Genovese leaf. Sweetly fragrant and, in some strains, puckered like lettuce, these leaves are made for wrapping mozzarella, fish or rice, and for pesto by the bowlful. An unsung basil that belongs in every garden.
The name
Let us start at the beginning. Ocimum basilicum is the botanical name of sweet basil: Ocimum the genus, basilicum the species, from the Greek word for “royal”. The species alone says nothing about leaf size; Genovese, Napoletano and Mammoth all fall within it. Only Ocimum basilicum ‘Napoletano’ names the cultivar. “Bolloso” describes the blistered, puckered leaf surface, “a foglia di lattuga” means lettuce-leaved, “Napoletano” Neapolitan.
| Language | Names |
|---|---|
| Italian | Basilico Napoletano, Bolloso Napoletano, Gigante Napoletano, Riccio Napoletano, Basilico a Foglia di Lattuga |
| English | Napoletano basil, Neapolitan basil, Lettuce Leaf basil, Mammoth basil |
| German | Salatblättriges Basilikum, Neapolitanisches Basilikum, Großblättriges Basilikum |
| French, Spanish | Basilic à feuille de laitue; Albaca de hojas de lechuga (historical) |
The names overlap, but they do not guarantee identical seed. Mammoth, Lettuce Leaf and Napoletano are not automatically one cultivar; “Italian Large Leaf” is especially broad, and ‘Valentino’ is a related selection, not a dependable synonym.
Where it comes from
Basil has long been cultivated in Asia and, later, around the Mediterranean. Where the giant-leaved form comes from is unresolved. Its association with Naples and Italian cooking is strong, but no first breeder, and no unbroken line from an early Italian selection to today’s packet, has been established.
The Naples Botanical Garden preserves seed and plant catalogues from 1807, 1813, 1824, 1833, 1845 and 1855; its director Michele Tenore (1780–1861) wrote the Flora Napolitana. A letter of 8 January 1834 records Tenore sending the 1833 catalogue to Turin and Geneva, seed exchange between three gardens. It does not prove that a lettuce-leaved basil was among the seed; the catalogues are a lead nobody has followed yet.
The earliest known description is French: Basilic à feuille de laitue in Vilmorin-Andrieux’s Description des plantes potagères (1856, after a preliminary publication in 1855), broad, pale-green, blistered leaves resembling a headed lettuce. Les Plantes potagères of 1883 adds an illustration and a fuller description: leaves 5–10 cm long, broad, blistered and undulating, on fairly compact plants, with fewer leaves than ordinary basil, and the Spanish name Albaca de hojas de lechuga. The English edition appeared in 1885 under William Robinson. What is described is an existing variety; nobody claims its invention. Neither Tenore nor the Vilmorin family should be credited as its breeder.
How a leaf gets this big
The most plausible explanation is traditional selection: growers save seed from plants with unusually large, tender, aromatic leaves and repeat the process generation after generation. Comparing offspring, avoiding unwanted crossing and keeping the seed pure gradually stabilises a strain. That describes the method, not the forgotten breeder in Naples.
In 2006 S. Elementi, R. Neri and L. F. D’Antuono reported a five-year study of European sweet basil: 60 strains, then about 200 progenies from crosses of Genovese, Foglia di Lattuga and Compatto. The aim was to combine the Genovese aroma with larger leaves. Genovese had more essential oil and linalool, with almost no methyl chavicol; Foglia di Lattuga had much more methyl chavicol, and its accompanying mint note was considered undesirable for that market. A giant leaf and the preferred aroma were, for a long time, two separate breeding goals.
In the US, James E. Simon’s programme at Rutgers University has bred for aroma and downy-mildew resistance since 1986 (‘Rutgers Devotion DMR’ and others). Modern programmes weigh aroma, yield, uniformity, shelf life and disease resistance; a spectacular leaf alone was once distinguishing feature enough.
Varieties and relatives
| Name | How to read it |
|---|---|
| Napoletano, Bolloso Napoletano | The traditional Neapolitan type: broad, light-green, strongly blistered leaves. The RHS records Bolloso Napolitano and Gigante Napoletano as synonyms. |
| Foglia di Lattuga, Feuille Laitue | The Italian and French lettuce-leaf names; different seed houses maintain different strains. Franchi lists Foglia di Lattuga and Bolloso Napoletano separately. |
| Lettuce Leaf, Mammoth | English trade names for exceptionally broad-leaved forms; not every packet is genetically Napoletano. |
| Napolitana | A named selection, for instance Kiepenkerl’s. |
| Valentino, Italian Star | Related large-leaved selections, not substitutes for the historical type. |
| Genovese, Italian Large Leaf | Comparisons for flavour and yield; large leaves alone do not make a puckered lettuce leaf. |
| Tuscan giant basil (Valdarno) | A regional lettuce-leaved form, associated in Tuscany with panzanella. |
Pinetree Garden Seeds in the US gives Japan as the origin of its Lettuce Leaf basil, with leaves of 8–13 cm. Japanese sources count the Italian Bolloso Napoletano within the same group; a separately bred Japanese cultivar is not established. Japan’s tradition of using shiso leaves as wrappers is a lovely culinary parallel, but shiso is Perilla frutescens, a different plant.
How big is giant
| Source | Leaf length |
|---|---|
| Vilmorin, 1883 | 5–10 cm |
| Auenland, Foglia di Lattuga | 8–12 cm |
| Pinetree, Lettuce Leaf | about 8–13 cm |
| Napoletano, general descriptions | about 12–13 cm |
| Baker Creek, Lettuce Leaf | up to about 15 cm |
| Botanical Interests, Lettuce Leaf | up to about 15 × 10 cm |
| Franchi, Foglia di Lattuga | “larger than a hand” |
These are supplier descriptions, not results from a controlled comparison. In 2012 SuperCloset in San Francisco reported a hydroponically grown basil leaf of 32 square inches, about 206 cm²; the World Record Academy carried the story and referred to an 18-square-inch leaf grown by Susan Sauter in West Virginia in 1996. Guinness certification is not established.
The raised, quilted areas between the veins are called bullation. They make the leaf striking and hold dressing or sauce; broad, flexible leaves make good wrappers. The folds prove neither greater photosynthesis nor drought tolerance, and moisture may linger in them. Very large individual leaves do not necessarily mean a heavier harvest either: Vilmorin already noted that the plants carry fewer leaves.
Seed
Franchi Sementi (Italy, through Seeds of Italy in the UK and Seeds from Italy in the US) lists Foglia di Lattuga and Bolloso Napoletano; Vilmorin and La Bonne Graine (France) Basilic à feuille de laitue; Thompson & Morgan and Chiltern Seeds (UK) Lettuce Leaf and Napoletano. In the German-speaking countries: Auenland (A Foglia di Lattuga, Demeter), Magic Garden Seeds (Neapolitanisches Basilikum), Samenliebe (Italienischer Neapolitano), Kiepenkerl (Napolitana), Sperli (Italian Star), Bloomling (Franchi’s Bolloso Napoletano).
Austrosaat currently has no true Napoletano. Its range has the large-leaved basils ‘Hohes Grünes Superbo’ and ‘BIO Hohes Grünes’ (both 45–60 cm tall), and ‘Siam Queen’ and ‘Cinamonette’ with anise and cinnamon notes. A growing trial of Napoletano against Superbo, for flavour, yield and reliability, would make a worthwhile story for a seed packet with a QR code.
In the kitchen
Italian descriptions speak of a sweet, delicate flavour, strong fragrance, soft young leaves and sometimes a mint note. Orto Mio describes the aroma as intense but more delicate than Genovese; Sale&Pepe gives a gentler flavour with a characteristic mint note. Leaf size says nothing about the strength of the aroma.
In Naples the large leaves are traditionally wrapped around buffalo mozzarella and drizzled with olive oil. What else works:
- Wrappers: fold a young, flexible leaf around mozzarella and tomato, grilled vegetables or another small filling; the leaf becomes part of the dish.
- Caprese and sandwiches: one leaf covers a slice of tomato or mozzarella.
- Pizza Margherita: the broad leaves as a conspicuous, aromatic finish.
- Sauces and passata: torn leaves, added earlier or later for the intensity you want.
- Panzanella: the Tuscan connection; tear the leaves into the bread-and-tomato salad.
- Fried: Sale&Pepe recommends large Napoletano leaves fried singly as crisp garnishes.
- Pesto: it works, but the aroma differs from the Genovese profile of Ligurian pesto.
- Fish, meat and rice: as wrappers, as Japanese growers describe.
A simple comparison: taste equally young leaves of Napoletano, Vilmorin’s lettuce-leaf basil and a Genovese side by side, for fragrance, sweetness, mint or anise notes, tenderness and how easily the leaf folds. Then repeat with tomato and olive oil. A leaf that is spectacular in a photograph is not the first choice for every dish.
Growing
A glasshouse helps but is not essential. Basil grows outdoors through warm summer weather in a sunny, sheltered spot; in cooler locations protection is worth it.
Sow thinly in moist seed compost at about 20 °C. Keep seedlings warm and bright, then pot them on. Harden off before planting out, only after the last frosts and once nights stay reliably above 10 °C. Well-drained soil, or a container at least 20 cm wide and deep.
Keep the moisture even without waterlogging; water in the morning and keep the leaves dry. Container plants are grateful for a balanced liquid feed. Harvest shoot tips regularly to encourage branching, and remove flower stems so the plant keeps making leaves.
Watch for slugs, snails and aphids. Seedlings can damp off; older plants develop grey mould in the wet. Do not overcrowd, and ventilate the glasshouse. Cold and damp is the worst of all. (Growing guidance after RHS, “How to grow basil”, consulted 13 October 2026.)
If you want to know for sure: label each seed source separately, measure leaves of the same age, photograph them beside a ruler, then record the number of usable leaves and the harvest weight. That distinguishes a single impressive leaf from a productive kitchen plant.
Further watching
- RHS: how to grow basil
- Sowing and planting on video: part 1, part 2
- Orto Mio (Italy) shows the growing on its YouTube channel.
- Les Plantes potagères, 1883: Basilic grand