How to Grow Lavender Grosso

Lavender Grosso

Lavandula × intermedia 'Grosso'

shrub

Lavender Grosso is a vigorous hybrid lavender cultivar known for its large, densely-packed purple flower spikes and strong fragrance. It is a semi-woody perennial shrub that blooms prolifically from early to midsummer and is highly prized for ornamental displays, cut flowers, and essential oil production. The plant grows robustly with silvery-green foliage and is more heat and drought-tolerant than many other lavender varieties.

Growing Conditions

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Sun: Full sun, 6-8 hours daily; thrives in hot, sunny locations

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Water: Drought-tolerant once established; water moderately during growing season, allowing soil to dry between waterings. Reduce watering significantly in winter. Overwatering is the primary cause of failure.

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Spacing: 24 inches

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Days to maturity: 90-120 days to significant bloom from transplant; reaches mature size in 2-3 years

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Planting depth: Transplants should be planted at same depth as root ball; seeds sown 1/8 inch deep

Soil

Type: Well-draining sandy or gravelly loam

pH: 6.5-7.5

Amendments:

Perlite or coarse sand for drainage improvement Gravel mulch to prevent root rot Avoid excessive compost or rich organic matter

Growing Zones

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Thrives in zones 6-9; hardy to zone 5b with winter protection

5b 6a 6b 7a 7b 8a 8b 9a 9b

Growth Stages

Establishment

4-8 weeks

Young plants develop a root system and basal foliage rosette with narrow, silvery-green leaves.

Water moderately to establish roots but allow soil to dry between waterings. Protect from excessive moisture. Mulch lightly with gravel around the base.

Vegetative Growth

2-3 months

The plant expands in width and height, producing bushy growth with increasingly dense silvery foliage.

Minimal fertilizer needed; too much promotes leafy growth over flowers. Prune lightly in early spring to shape and encourage branching.

Budding & Flowering

6-8 weeks

Tall flower spikes emerge from branch tips, gradually filling with densely-packed purple florets. Peak bloom occurs in early to midsummer.

Deadhead spent flowers to encourage additional blooms. Provide consistent but dry conditions. Do not overwater during this period.

Post-Bloom & Hardening

2-3 months

Flowers fade and set seed; foliage transitions to a deeper green-gray tone. The plant prepares for dormancy.

Cut back flower stems in late summer or fall to tidy appearance and promote next year's growth. Significantly reduce watering.

Winter Dormancy

3-4 months

Plant enters dormancy with minimal visible growth; silvery foliage remains attractive and evergreen.

In zones 5-6, provide winter mulch with gravel or coarse sand (not organic mulch). Ensure excellent drainage. Water very sparingly.

Companion Planting

Plan your garden →

Plant with:

Rosemary Sage Thyme Santolina Catmint (Nepeta) Russian Sage Sedums Coreopsis Salvia Germander

Avoid planting near:

Plants requiring frequent watering (hydrangeas, ferns, impatiens) Competing for root space in wet soils Heavy feeders in rich soil environments

Common Pests

Ensure excellent soil drainage; avoid overwatering; plant in raised beds if necessary; apply copper fungicide as preventative in humid climates
Improve air circulation by pruning; water at soil level only; avoid overhead watering; remove affected foliage; apply sulfur dust if severe
Generally non-damaging; introduce beneficial insects; remove heavily infested foliage if necessary
Increase humidity slightly; spray with water; apply insecticidal soap; ensure plant is not heat-stressed
Hand-pick in early morning; use pheromone traps; apply neem oil in evening

Uses

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Culinary & Beverages

Culinary

Lavender Grosso flowers can infuse teas, honey, baked goods, and desserts with a sophisticated floral flavor. The flowers must be food-safe and pesticide-free. [source]

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Cut Flowers & Dried Arrangements

Craft

Lavender Grosso is exceptional for cut flower arrangements, both fresh and dried, with excellent vase life and long-lasting fragrance. The large, showy flower spikes are ideal for florists and decorative displays. [source]

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Essential Oil & Aromatherapy

Medicinal

Lavender essential oil is renowned for its calming and relaxation properties, used in aromatherapy diffusers, massage oils, and wellness products. Lavender Grosso produces high-quality essential oil with strong aromatic compounds. [source]

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Fragrance & Sachets

Household

Dried lavender flowers are used in sachets, closet fresheners, pillow fillings, and linen sprays for their persistent, pleasant aroma. The strong fragrance of Grosso makes it excellent for this purpose. [source]

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Pollinator Support

Wildlife

Lavender Grosso is highly attractive to bees, butterflies, and other pollinators, making it an excellent choice for pollinator gardens and supporting biodiversity. [source]

This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.

Harvest Tips

Cut flower spikes when 1/2 to 2/3 of the florets are open for the finest fragrance and color; harvest in the morning after dew dries. For dried flowers, cut at the same stage and hang upside down in bundles in a well-ventilated space for 2-3 weeks. For essential oil production, harvest at peak bloom. Lavender Grosso is known for abundant, continuous flowering, allowing multiple harvests per season.

Fun Facts

🌱 Lavender Grosso is a hybrid between Lavandula angustifolia and Lavandula latifolia, combining the cold-hardiness of one parent with the vigor and oil production of the other.
🌱 The name 'Grosso' means 'large' in Italian, referring to the notably large and dense flower spikes this cultivar produces compared to other lavender varieties.
🌱 Lavender has been used for centuries in perfumery, medicine, and household applications; the name likely derives from the Latin 'lavare,' meaning 'to wash.'

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