Trachelium Caeruleum Passion In Lilac

Trachelium Caeruleum Passion In Lilac Seeds

(Compact Ornamental Throatwort — Lilac)

Trachelium caeruleum, known as Throatwort, is a Mediterranean native in the Campanulaceae family that produces its distinctive dome-shaped flower heads densely packed with hundreds of tiny star-shaped florets. Passion in Lilac belongs to Sakata’s Passion In series — a compact, ornamental bedding and pot plant line developed for home garden appeal rather than professional cut flower production.
Passion In is an attractive eye-catcher developed as a great centrepiece for large mixed containers or for growing in the garden as a home garden cut flower. The compact plant habit comes with outstanding branching, large and very decorative umbels, and heat tolerance — making it an attractive product in packs or large containers.

The lilac color of Passion in Lilac is a cool, soft blue-purple tone — lighter and more delicate than violet or deep purple Trachelium varieties, and particularly effective in mixed pastel container arrangements. The large dome-shaped umbels provide exceptional cloud-like texture that adds depth and visual complexity to any display, whether grown as a standalone pot plant or combined with other cool-season flowers.

The Passion In series from Sakata is specifically distinguished from professional cut flower Trachelium varieties by its compact 30 cm height and its primary focus on ornamental pot and garden display. The Passion In Violet, the sister color in this series, was recognized as a Fleuroselect Approved Novelty in 1996 — reflecting the series’ ornamental quality and innovation. The outstanding branching of the Passion In plants means multiple umbels develop simultaneously, creating a full, generous display rather than a single central flower head.

An important practical advantage of Passion in Lilac over professional cut flower Trachelium varieties for Gulf growers is its heat tolerance and compact habit — the plant is better suited to Gulf outdoor conditions and the slightly warmer end of the cool season, making it more accessible for home gardeners without specialist growing equipment.

Variety Details

• Variety: Passion in Lilac
• Series: Passion In
• Breeder: Sakata Seed (Japan)
• Flower color: Lilac (soft blue-purple)
• Flower form: Large decorative dome umbels
• Height: 30 cm
• Spread: 20 cm
• Habit: Compact, upright, outstanding branching
• Primary use: Bedding plant, mixed containers, home garden cut flower
• Heat tolerance: Yes
• Pot size: 10.5–12 cm recommended

Key Features

• Compact ornamental Throatwort from Sakata — bred for home garden and container use.
• Large, highly decorative soft lilac dome umbels with outstanding branching.
• Compact 30 cm habit — ideal for containers, mixed pots, and front-of-border.
• Heat tolerance — extended seasonal performance compared to professional cut flower varieties.
• Multiple umbels produced simultaneously — generous, full display.
• Excellent as a centrepiece in large mixed container arrangements.
• Can be used as informal home garden cut flower.
• Sister variety to Fleuroselect-recognized Passion In Violet.

Plant Information

• Height: 30 cm
• Spread: 20 cm
• Plant type: Half-hardy annual (short-lived perennial in frost-free zones)
• Habit: Compact, upright, very well-branched
• Sun: Full sun to partial shade
• Soil: Fertile, well-drained soil, pH 6.0–7.0
• Water: Consistent moisture — keep evenly moist; do not waterlog
• Spacing: 20–25 cm apart; suitable for 10.5–12 cm individual pots
• Recommended pot size: 10.5–12 cm

Seed Germination

• Seed depth: Surface sow — do NOT cover; seeds require light to germinate
• Germination time: 8–30 days
• Ideal germination temperature: 20–22°C
• Important: Surface sow on moist, fine, sterile seed-starting compost at 20–22°C.
• Do not cover seeds as light is essential for germination.
• Keep continuously moist throughout germination by misting or sub-irrigation — avoid disturbing the tiny pelleted seeds.
• Trachelium is sensitive to high salt levels, particularly ammonium — do not fertilize during the germination stage.
• Seedling growth is slow — allow 10–12 weeks from sowing to transplant-ready size.

Growing Tips

• Sow Passion in Lilac seeds on the surface of a fine, moist, sterile seed-starting compost at 20–22°C.
• Do not cover seeds. Water gently using a mist sprayer to avoid displacing the seeds.
• Keep continuously moist in a bright, warm position.
• Germination takes 8–30 days and seedling growth is slow — patience is important in the early stages.
• Once seedlings develop their first true leaves, pot up carefully into small individual cells and grow on in a bright, well-lit position at a minimum of 15°C.
• After 10–12 weeks from sowing, plants are ready for their final 10.5–12 cm pots or garden position.
• Plant in fertile, well-drained soil or potting mix in a full sun to partial shade position.
• Keep the crown at or above soil level.
• Water consistently at the base of the plant.
• Begin feeding every two weeks with a balanced fertilizer once plants are established and showing good growth, continuing throughout the flowering period.
• The outstanding branching habit of Passion in Lilac means the plant fills its pot or garden space naturally and generously without much intervention.
• Deadheading spent umbels encourages the development of new side shoots and prolongs the ornamental display. For home garden cut flower use, cut stems when the central umbel is fully open and side umbels are beginning to develop.
• Passion in Lilac is suitable for Gulf outdoor cool-season growing without supplemental lighting, unlike professional cut flower Trachelium varieties.
• Its heat tolerance means it can also perform through the transitional periods at the start and end of the Gulf cool season.

Gulf Planting Season

• Best sowing time in the Gulf: August–September (indoors)
  Transplanting: October–November
  Expected flowering: December–March
  Note: Heat tolerance allows performance through the warmer transition periods of the Gulf cool season.

Garden and Floral Uses

• Mixed container centrepiece — outstanding in large decorative pots
• Bedding and front-of-border planting
• Window boxes and patio displays
• Informal home garden cut flower
• Mixed arrangements with cool-season annuals
• Combined with snapdragons, lisianthus, and soft-toned flowers in arrangements