• AGM plants

    AGM plants have been through a rigorous trial and assessment programme. They are:

    • Excellent for ordinary use in appropriate conditions
    • Available to buy
    • Of good constitution
    • Essentially stable in form & colour
    • Reasonably resistant to pests & diseases

Unique new petunia for baskets and borders

Glorious new cultivar changes colour with the seasons

New petunias arrive in our garden centres, catalogues and on websites every year. Larger-flowered or smaller-flowered; neater and bushier or vigorous ground cover; new colours and colour combinations, of course. But few can be as genuinely different as 'Night Sky'*.
The deep purple-blue single flowers are unpredictably speckled in large and small white spots so they look like stars shining in the night sky. The plants develop a strong semi-trailing habit, so are ideal in hanging baskets and they can also be treated as summer ground cover plants and grown in sunny borders where the plants will spread to 60-75cm (24-30in).

These striking flowers are the result of many years of careful selection by Italian plant breeder Antonella Capo; the target being to obtain a stable colour pattern.

Colour responding to the seasons

However, it’s worth noting that this lovely new colour pattern is not 100% stable. When the summer weather provides us with hot days and cool nights the white colouring will tend to predominate and white flowers with a purple star pattern may appear. On the rare occasions when day and night temperatures are unusually high – above 24°C (75°F) during the day and above 17°C (63°F) at night – the colouring may become almost solid purple.
The ideal temperatures are 14-24°C (57-75°F) during the day and 11-17°C (52-63°F) at night and this is a range that most of us expect in summer and should provide us with the classic, prettily starry flowers.
Night Sky won the 2015 Fleurostar award for the most stunning new plant of the year and was also a favourite amongst visitors to Britain’s most prestigious flower trials last year. It is propagated vegetatively, not from seed.

You can order plants of Petunia 'Night Sky' from Blooming Direct, and from Brookside Nursery, and from J. Parker’s, and from Thompson & Morgan. It will also be in good garden centres later in spring.


More information

See more petunias here
RHS advice on buying and growing bedding plants
RHS advice on container planting, selection, and maintenance
RHS advice on plant feeding

* This plant's official botanical name is Petunia Night Sky = ‘KLEPH15313’

** Please note the contents of this blog reflect the views of its author and are not necessarily those of the RHS

Discuss this

for the site or to share your experiences on this topic and seek advice from our community of gardeners.

Get involved

The Royal Horticultural Society is the UK’s leading gardening charity. We aim to enrich everyone’s life through plants, and make the UK a greener and more beautiful place.