We're offering you a Giant Petunia Mixed Collection for £5.99, saving you up to 40% off Thompson and Morgan's's price of £9.99 (correct as of 07.05.2026).

Transform Your Summer Garden with Giant Petunia 'Allegra F1'

Petunia 'Allegra F1', an Italian-bred breakthrough, brings unrivalled height and opulent double blooms to your outdoor space. Reaching up to 150cm (5ft) tall and spreading to 75cm (30in), this exceptional perennial delivers a spectacular vertical presence far beyond ordinary petunias.

• Breathtaking Blooms: Each stem produces masses of fully double flowers up to 12cm across in pastel lavender, magenta-white bicolour, and pure white shades. Enjoy continuous colour from early summer through autumn.
• No Fuss, All Beauty: This male-sterile variety naturally sheds spent blooms—so you spend less time deadheading and more time admiring your display.
• Perfect Indoors & Out: Strong stems hold over 20 blooms per stem, making them a standout choice for long-lasting cut flower arrangements (7–10 days in water).
• Mediterranean Heritage: Developed on the slopes of Mount Vesuvius, these petunias thrive in UK gardens with robust growth and outstanding weather resistance.

Growing Guide & Care Tips

• Planting Time: Plant plug plants after the last frost—typically from late April through May.
• Sun Requirements: Choose a spot in full sun for best flowering performance.
• Soil Preferences: Prefers fertile, well-drained soil. Add organic matter before planting for extra vigour.
• Irrigation: Water regularly during dry spells; avoid waterlogging.
• Pests & Diseases: Generally pest resistant but watch for aphids or slugs in damp conditions.
• No Deadheading Needed: Enjoy effortless maintenance thanks to self-cleaning blooms.

'Allegra Collection' Varieties Included

• 'Allegra Pastel Orchid': Soft lavender tones bring gentle elegance.
• 'Allegra Picotee Velvet': Striking magenta with white bicolour edges for bold contrast.
• 'Allegra Pure White': Crisp white blooms create a fresh, classic look.

Clever Design Ideas & Companion Plants

• Create dramatic borders by pairing with upright salvias or ornamental grasses.
• Add height and structure to patio containers alongside trailing lobelia or bacopa.
• Makes a show-stopping centrepiece in mixed summer bedding schemes.

FAQs

• When is the best time to plant these petunias?
  The best time is after the last frost in spring—typically late April or May in the UK.
• How tall do they really grow?
  This variety can reach up to 150cm (5ft) when grown in ideal conditions with full sun and good soil.
• Do I need to deadhead the flowers?
  No—these petunias are male-sterile and naturally drop spent blooms, so maintenance is minimal!