SproutSmart
SproutSmart™ Intelligent Garden Sowing

Grosso

Lavender
Botanical illustration of Grosso
🌱 365d to harvest Shrub

Breathe in the unmistakable, cool-sweet perfume of Grosso Lavender—an aromatic standout with long, richly colored flower spikes t…

Zone 8a Save Garden

Planting Schedule

Add Grosso to your garden to build a schedule and get reminders.

Crop Dates

Growing note: Zone 8a has only 218 frost-free days — shorter than this crop's 365-day maturity. Outdoor planting is not viable; use protected cultivation.
MilestoneDate
Last FrostApr 1st
Growing ApproachProtected Environment Only

Crop Details

TraitValue
Days to Maturity365
Sun RequirementsFull SunFull sun
Growth HabitShrub
Support NeededNone
Planting DepthNormal
Germination Temp (°F)70
Min Soil Temp (°F)60
Min Night Temp (°F)45
Harden Off (days)Not Required

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Frequently Asked Questions

What pest or disease most commonly affects Lavandula × intermedia (Grosso), and how do I manage it?
The most common problem is root rot from poorly drained soil, which shows up as sudden wilting, yellowing, and blackened roots. Water only when the top 1–2 inches of soil are dry, plant in fast-draining ground or raised beds, and avoid wet foliage. If plants decline despite good drainage, remove the affected stems/plant and replant in fresh, well-drained soil to prevent spreading.
How often should I water Grosso lavender during the main growing season?
During active growth, water deeply about once every 7–14 days, but only when the top 1–2 inches of soil feel dry. Grosso (Lavandula × intermedia) tolerates drought once established, so frequent light watering can keep roots too wet and increase rot risk. In hot, windy weather you may need the shorter end of that range; in cool or rainy periods, pause watering entirely.
How can I tell when Grosso lavender is ready to harvest?
Harvest when most flower spikes are in color but the lower florets haven’t opened fully—about when the buds on the spike start to swell and the first flowers begin to show. Use a gentle touch: the spikes should feel firm, not papery or dried out. For best fragrance, cut on a dry morning and harvest before full bloom for the most consistent oil-quality.
Botanical illustration of Grosso

Breathe in the unmistakable, cool-sweet perfume of Grosso Lavender—an aromatic standout with long, richly colored flower spikes that hold their fragrance as they dry. Expect a dense, upright habit with silvery foliage that feels softly velvety to the eye, and blossoms that deliver a concentrated, floral-lavender character. Grow Grosso for its showy, long-lasting blooms in the garden and for fragrant potpourri and sachets, or to scent your favorite homemade aromatic blends.

Sowing Tips

Transplant Conditions

Wait until soil reaches 60°F and nights stay above 45°F before moving outdoors.

Expert Note

For Grosso lavender, aim for full sun and excellent drainage—don’t overwater, and keep seedlings/roots from staying wet during establishment.