Like favorite guests, F1 Prism Sunshine come early and stay very late! This multiple award winner is considered the best yellow Petunia not only for its big, colour-drenched blooms, but for the uniform, compact plants that bloom early and heavily, and continue over a long season. It is the first yellow petunia that retains its colour throughout the summer.
The glorious 8 to 10cm (3 to 4in) blooms just keep coming all season, continuing for several weeks after others have given up. Part of this endurance is due to great resistance to adverse weather, from rain and humidity to warm nights. Prism Sunshine is free-flowering and keeps its neat, mounded habit and plentiful blooms through it all.
The Grandiflora type plants reach around 20 to 25cm (8 to 10in) tall, making them a great size for the garden, baskets and containers.
The combination of beautiful blooms and great garden performance impressed both the All-America Selections committee and the Fleuroselect Gold Medal judges - it received top honours from both organisations.
Sowing: Sow indoors from February, 8 to 10 weeks before last frost.
Petunias flower early and are covered with stunning blooms. They like the sun and often bloom within two months from seed and continue throughout the season until killed by the frost. They are easily cultivated, requiring rich soil and full sun. They grow best in high-moisture areas with well-drained soils, but can adapt to most soil types. Established plants are drought resistant, requiring less dry-weather maintenance than other plants.
Plant seeds 6mm (¼in) inch apart, in rows 7cm (3in) apart and gently firm (especially the corners), so you don't get erosion when watering. Do not cover the seed, as the seeds need light to germinate.
Provide light and constant warmth of 21 to 27°C (70 to 80°F). Use a bottom heat source for best results. F1 hybrids tend to germinate better at the higher end, at around 27C (80F). The soil temp should not fluctuate and must not drop below 21°C (70°F). Finely mist and cover seed tray with plastic or paper to conserve moisture.
Check the compost for dryness regularly. If this is the case, add a little warm clean water from below, being careful not to over water. Too much water can kill seedlings, as it can spread "damping off fungi", and encourage other moulds and diseases.
Germination usually takes 10 to 21 days depending on soil and temperature conditions. Remove cover as soon as seeds sprout. Keep moist and do not use cold water as it lowers the soil temp and weakens tender seedlings.
When seedlings are large enough to handle, transplant and grow on in cooler conditions, around 13 to 16°C (55 to 60°F) for stocky plants.
Gradually acclimatize to outdoor conditions for 10 to 15 days before planting out after all risk of frost, 30cm (12in) apart in a sunny spot on light well drained soil. For pot plants, transplant the seedlings into 7.5cm (3in) pots, grow cool, well ventilated and give plenty of light, but shade from direct sun.
When plants are 5 to 10cm (2 to 4in) tall, and ground is warm, transplant to their final positions in pots or into the garden, spacing 20 to 30cm (8 to12in) apart. Plant in a full sun location. They will tolerate light shade but blooming will be reduced. Use a low-nitrogen/high-phosphorus fertilizer sparingly. Do not overwater or over fertilise, Overwatering will yellow and kill the plants.
After planting into baskets, when established give them a good spray from a watering can. The weight of the water flow will produce a perfect cascading habit.
For denser plants and more flowers, pinch or shear when 15cm (6in) tall and keep faded flowers picked.
Petunias are sticky and will attract greenfly so keep an eye on them. Don't over water in the winter and keep them well ventilated.
Petunias are generally sold and grown as half hardy annuals (they will tolerate slight frost and flower in the first year from seed) but in their native countries of Brazil and Argentina they are a perennial.
The plants can be over wintered by lifting in the autumn, trimmed back to about 15cm (6in), then potted up into a well drained potting compost. The plants can then be placed on a cool 13°C (55°F) well lit window sill and planted out in the early summer.
Window boxes, containers, tubs, hanging baskets and pot plants.
This popular flower derived its name from French, which took the word petun 'tobacco' from a Tupi-Guarani language. Trailing petunias were once listed as forms of P. pendula.
Botanically speaking it is in the family Solanaceae, together with tobacco, tomato, potatoes and chili peppers.
The species was first sent from South America to Paris in 1823. It was discovered in South America by the explorer James Tweedie, (after whom the genus Tweedia is named), who sent specimens to the Glasgow Botanical Garden in 1831.
Most of the varieties seen in gardens are hybrids (Petunia x hybrida), they were among the first ornamentals to be bred for the bedding plant market in the 1950s.
The origin of P. x hybrida is thought to be by hybridisation between P. axillaris (the large white or night-scented petunia) and P. integrifolia (the violet-flowered petunia). P. axillaris bears night-fragrant, buff-white blossoms with long, thin tubes and somewhat flattened openings. P. integrifolia has spreading stems with upright tips, and small lavender to purple flowers.
- Additional Information
Packet Size 50 mg Average Seed Count 50 Seeds Family Solanaceae Genus Petunia Species x hybrida Cultivar F1 Mirage™ Buttercream Common Name Grandiflora Petunia Hardiness Tender Perennial often used as an Annual Flowers Large, 8 to 10cm (3 to 4in) yellow flowers Natural Flower Time Summer through to first frosts Height Pot 15 to 20cm (6 to 8in). Garden 23 to 30cm (9-12in). Spread 25-30cm (10-12in) Position Full Sun Soil Well-drained/light Time to Sow Sow indoors from February. Growing Period 75 to 85 days to first flower. Germination 10 to 21 days at 21 to 27°C (70 to 80°F).