HerbBasil
Treviso Basil
Treviso Basil is an All-America Selections National Winner that brings Italian heritage and modern vigor to any garden. This compact, tightly mounded annual reaches just 18-24 inches tall and produces bright green, sweet leaves with a subtle anise scent that stay remarkably tender and resist the bitterness that can plague basil in heat. Bred for exceptional vigor and heat tolerance across hardiness zones 3-11, it's slow to flower and resistant to both downy and powdery mildews, making it reliable for 90 days of continuous harvesting. Whether you're growing in the ground, raised beds, or containers, Treviso delivers the tender leaves pesto makers dream of.
Photo © True Leaf Market
Growing Conditions
USDA Zone
3-11
Sunlight
Full Sun
Water
High
Soil
Well-drained, Fertile Loam
Growth Stats
24 in
Height
TypeBush
Spacing
12
Plant Profile
Sunlight
Full Sun
Water
High
Zones
3-11
Size
24in H x ?in W
Growth
—
Care
High
Hover over chart points for details
Highlights
Treviso stands out for its highly branched, mounded form that naturally encourages leaf production without aggressive pruning. The bright green leaves carry a sweet, slightly anise-scented flavor that deepens when used fresh in pesto, and the variety's resistance to both downy and powdery mildews means you'll be harvesting clean foliage all season long. Its slow-flowering tendency keeps leaves tender rather than steering the plant toward seed production, a trait that separates it from less disciplined basil varieties. Heat and vigor run through every part of this plant, making it one of the rare basil cultivars bred specifically to perform in challenging conditions.
Common Uses
This is a pesto specialist first and foremost, though its tender, sweet leaves shine across the entire spectrum of fresh basil applications. Tear leaves raw into caprese salads where their sweetness and subtle anise notes complement tomato and mozzarella beautifully. Use Treviso for fresh herb butters that melt over hot pasta or grilled vegetables, as the leaves maintain their delicate structure. It excels as a garnish where visual appeal and tender texture matter, and its flavor holds up in pizza toppings and all-season cooking.
Growing Timeline
No timeline data available yet for this variety.
Care Instructions
Start Indoors
Start seeds indoors 6-8 weeks before your last frost date, sowing at a depth of 1/4 inch in warm seed-starting mix kept at 70-75 degrees Fahrenheit. Basil germinates best with warmth and light, so provide supplemental lighting if seedlings stretch. Keep soil consistently moist but not soggy. Thin seedlings to allow good air circulation once they develop true leaves.
Transplant Outdoors
Transplant outdoors after your last frost date when soil has warmed to at least 60 degrees Fahrenheit, ideally closer to 70 degrees for robust growth. Harden off seedlings over 7-10 days by gradually exposing them to outdoor conditions. Space plants 12 inches apart in rows 18 inches apart, or space 12 inches apart in all directions for container growing.
Direct Sow
Direct sow seeds outdoors after soil temperature reaches 70 degrees Fahrenheit. Sow seeds 1/4 inch deep and keep soil consistently moist until germination, which typically occurs in 5-10 days in warm conditions. Thin seedlings to 12 inches apart once they develop true leaves.
Harvesting
Begin harvesting leaves once the plant has established 6-8 true leaves, typically around 3-4 weeks after transplanting or direct sowing. Pinch or cut leaves from the top 1-2 inches of the stem, always harvesting from above a set of leaves to encourage branching. Harvest in the morning after dew has dried for the best flavor concentration. Continue harvesting through the full 90-day cycle; frequent, gentle harvesting actually extends productivity by preventing flower formation. The leaves stay tender throughout the season due to this variety's slow-flowering nature, so you're not racing against bitterness the way you might with other basil cultivars.
Pruning
Pinch out the growing tip when plants reach 6 inches tall to encourage the naturally compact, highly branched habit. Regular harvesting serves as pruning; remove leaves from the top of the plant down to encourage lateral branching rather than vertical growth. Deadhead flowers as soon as they appear to redirect energy into leaf production and maintain tenderness. Because Treviso is slow-flowering, you have more flexibility than with other basil types, but removing flower buds will extend the productive season.
Growing Calendar
Enter your ZIP code to see a personalized growing calendar for this plant.
Companion Planting
Pests & Diseases
Ecology & Traits
Edible
Scientific Classification
Ocimum basilicum
Family
Lamiaceae
Genus
Ocimum
Growth Habit
Bush
Native Status
L48 (I)HI (I)PR (I)
History & Origin
“Treviso Basil earned its All-America Selections National Winner designation by proving itself across diverse growing regions. The variety represents the refinement of Italian Genovese-type basil, a line prized for centuries in the Liguria region of northern Italy where pesto tradition runs deep. This cultivar was explicitly bred to combine that classic Genovese character, sweetness, and leaf quality with modern disease resistance and heat tolerance, addressing the real frustrations gardeners face with conventional basil varieties. It's a bridge between heritage flavor and contemporary reliability.”