Night Sky Petunia

A distinctive variety producing purple to lavender blooms that are splashed with white spots; visually stunning in borders or patio containers

SKU: N/A Categories: Annuals, Plants & Flowers

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Species: Petunia

Plant Height: 14 in.

Spread: 30 in.

Evergreen: No

Plant Form: mounded

Summer Foliage Color: Green

Minimum Sunlight: Full Sun

Maximum Sunlight: Full Sun

Ornamental Features

Night Sky Petunia is smothered in stunning purple trumpet-shaped flowers with lavender overtones and white spots at the ends of the stems from mid spring to mid fall. Its pointy leaves remain green in color throughout the season. The fruit is not ornamentally significant.

Landscape Attributes

Night Sky Petunia is a dense herbaceous annual with a mounded form. Its medium texture blends into the garden, but can always be balanced by a couple of finer or coarser plants for an effective composition. This plant will require occasional maintenance and upkeep. Trim off the flower heads after they fade and die to encourage more blooms late into the season. It is a good choice for attracting hummingbirds to your yard, but is not particularly attractive to deer who tend to leave it alone in favor of tastier treats. It has no significant negative characteristics. Night Sky Petunia is recommended for the following landscape applications; Mass Planting Border Edging General Garden Use Container Planting Hanging Baskets

Planting & Growing

Night Sky Petunia will grow to be about 14 inches tall at maturity, with a spread of 30 inches. When grown in masses or used as a bedding plant, individual plants should be spaced approximately 24 inches apart. Its foliage tends to remain dense right to the ground, not requiring facer plants in front. This fast-growing annual will normally live for one full growing season, needing replacement the following year. This plant should only be grown in Full Sunlight. It does best in average to evenly moist conditions, but will not tolerate standing water. It is not particular as to soil type or pH. It is highly tolerant of urban pollution and will even thrive in inner city environments. This particular variety is an interspecific hybrid. It can be propagated by cuttings; however, as a cultivated variety, be aware that it may be subject to certain restrictions or prohibitions on propagation. Night Sky Petunia is a fine choice for the garden, but it is also a good selection for planting in outdoor containers and hanging baskets. It is often used as a ‘filler’ in the ‘spiller-thriller-filler’ container combination, providing a mass of flowers against which the thriller plants stand out. Note that when growing plants in outdoor containers and baskets, they may require more frequent waterings than they would in the yard or garden.

If you love that gorgeous fresh color that petunias can add to any garden, you may be wondernig – just how long would it take you to achieve the same look in yours? Once you seed or plant them – how long does it take to grow petunias and enjoy that wonderful array of colorful blooms?

Petunia seeds will germinate within one week if they are sown in ¼ deep potting soil that is both moist and fertilized. The soil temperature should be between 65 and 75 degrees Fahrenheit for optimum germination. The plants will grow fairly quickly if the proper growing conditions are met and should produce flower buds in as little as 6 to 8 weeks. Expect plants to take 10 to 12 weeks from seed sowing to flowering.

Now that you know the rate at which petunias grow, let’s take a look at this in more detail below. We will discuss how long it takes for petunias to grow from seeds as opposed to transplants. We will also explore the time it takes for the plant to bloom, what effect temperature has on their rate of growth, how long petunias last and whether or not they grow back each year.

So, if you’re ready to learn more about how long it takes to grow petunias, then let’s get started!

How Quickly Do Petunias Grow?

Petunias are a very popular flower that originated in Argentina, South America. There are many different types of petunias (over 35 known species) that come in a variety of colors, patterns, and sizes. They fill in space around plants in a garden and look beautiful against a backdrop of green foliage.

The speed at which you can get to that burst of color depends on how you grow them. Growing petunias from seed as opposed to transplants takes much longer, with more care and effort required.

Growing Petunias from Seeds

It takes approximately 7 to 10 days for petunia seeds to germinate, begin to grow and sprout. This is quite slow by growing standards. Begin indoors in late winter and sow petunia seeds in moist, fertile soil for about 10 to 12 weeks before the intended outdoor planting date in the spring.

To maintain consistent moisture levels, place a clear plastic dome, or some plastic wrap, over the planter or pot. Do not set the pot in direct sunlight at this time. The intense heat could inhibit or even prevent germination.

As soon as germinations occur, remove the dome or plastic wrap. Place the seedlings in a sunny window or under fluorescent lighting. Make sure the fluorescent lights are at least 4 to 6 inches above the plants and left on for 12 to 16 hours daily.

Growing Petunias from Transplants

Petunia transplants are easier to grow than petunia seeds with less time and effort on your part. You do not need to start them indoors and cuttings can be planted directly into a pot, hanging basket or garden bed immediately after purchasing. This saves you approximately 10 to 12 weeks of growing time.

Do Pelleted Petunia Seeds Grow Faster?

Pelleted seeds are seeds that are coated with a material to make them larger and easier to handle. Germination time can be up to 50 percent faster with pelleted (or primed) petunia seeds. The only downside is that they do not have the same storage life as unprimed seeds.

How Long Does it Take for Petunia Seeds to Grow?

Germination takes anywhere from 5 to 15 days for petunias that start indoors at average room temperature, which is 68 to 72 degrees Fahrenheit. If you are lucky enough to have a greenhouse and can keep them in a slightly warmer temperature (75 to 85 degrees Fahrenheit), they will germinate in as little as 3 or 4 days.

How Long Before Petunias Bloom?

Petunia seeds are very small and need a lot of light to germinate. They take anywhere from 6 to 8 weeks to flower. You should start them indoors in moist, fertilized soil and then move them outside after 10 to 12 weeks. Do not place them outdoors until the plants have a least 3 leaves. It is often easier and quicker to grow them from transplants.

Does Temperature Affect the Growth Rate of Petunias?

As the temperature rises, plants will grow faster. This goes for petunias as well. For the quickest flowering of petunias, they must be in areas with warm temperatures (65 to 75 degrees Fahrenheit) and long days with up to 16 hours of sunlight.

If petunias are planted in cooler temperatures (less than 65 degrees Fahrenheit), longer days will have less of an effect on their growth. They need heat to survive and to thrive. Therefore, if petunias are grown in very warm regions where the temperature reaches 75 degrees or higher consistently, they will continue to grow even in shorter days with 8 hours of sunlight or less, but not as well.

Where Do Petunias Grow the Fastest?

Petunias will grow the fastest in regions with warmer climates and hot, humid summers that are similar to Argentina, their place of origin. Long days and mild evenings (free of frost) provide the fastest growing conditions for these flowers.

How Long Do Petunias Last?

Petunias are perennials in warmer climates. They typically bloom during spring and summer, die back in autumn or winter and return again the following spring. Petunias have a natural limit to their lifespan and will eventually die back for good after 3 or 4 years. In cooler climates, they grow as annuals.

In regions where the climate is warm year-round, they often continue to bloom throughout the autumn and early winter months. It is usually recommended to keep petunias indoors during the winter if you want them to return again in the spring. Rarely will a petunia grow longer than 12 to 18 months.

Do Petunias Grow Back Every Year?

Petunias are often considered half-hardy annuals, even though they are actually perennials. They will usually survive the first frost, as long as it is light. They will not, however, survive a heavy frost and once frozen will die. Frost-injured plants can be cut back and what remains should outgrow the damage, thus allowing the plant to return again the following spring.


In summation, petunia seeds will germinate within one week, if they are sown in ¼ deep potting soil that is both moist and fertilized. The warmer the temperature, the quicker the petunias will grow. Therefore, soil temperature must be between 65 and 75 degrees Fahrenheit for optimal germination to occur.

If the proper growing conditions are met, the petunia plants should produce flower buds in as little as 6 to 8 weeks. It takes 10 to 12 weeks of indoor growing before petunias can be planted outside. Good luck and happy gardening!

Best of Show – Argyranthemum ‘Pure White Butterfly™’ from Proven Winners

Perfection came covered with white flowers in 2016. This plant had continuous blooms all through the growing season and looked fresh even during the summer heat. Plants maintained excellent uniformity and continuous growth helped “bury the dead” so that no dead heading was required.

Best New Variety – Lantana ‘Lucky™ Red from Ball FloraPlant

Flowers were abundant and had many citrus tones but predominately noted for a good dark red. This plant was unique for combining both the red flower color with a very uniform growth habit. Blooming started early in the season and was noted that it doesn’t cycle in and out of flowering like other lantanas.

Best Novelty – Begonia ‘Jurassic™ Red Splash from Ball Ingenuity

Fantastic foliage color gave this plant great interest as soon as it was planted in the garden. Foliage was a dramatic combination of red and silver with large jagged edges. A good choice for shady areas as it has iridescent foliage with the occasional beam of sunlight. Plants were well branched and also do well as an indoor plant.

___“Best Of…” by Class_____________________________________________

Angelonia ‘Archangel Dark Rose’ from Ball FloraPlant

Large flower spikes and a deep rose flower color gave this plant a lot of flower power. This plant is a great item for the landscape with dense, compact branching, glossy foliage and abundant flowering. It has won in this category in the past and has proven itself again in 2016.

Begonia boliviensis ‘Unstoppable Upright Fire’ from Dummen Orange

Dark foliage makes a great contrast with the bright orange flowers. Large flowers were semi-double and very abundant on vigorous plants. This plant is a good choice for containers.

Begonia semperflorens ‘Big® Red Bronze Leaf’ from Benary

Plants were characterized by their extreme vigor and prolific flowering. The dark foliage was very glossy and made a great contrast with the bright red flowers. Plants maintained excellent uniformity even with the vigorous growth. It is a good plant for either sun or shade areas.

Calibrachoa ‘Superbells Pomegranate Punch’ from Proven Winners

Flowers had a unique color combination that helped this entry receive a very high rating. Bloom color was similar to that of a pomegranate around the edges. Then it developed into a very rich, dark center with a small speck of bright yellow in the throat. Plants had a very uniform growth habit that was stunning in combination with the flowers in a container.

Canna ‘Toucan Scarlet’ from Proven Winners

Tall, beautiful plants with dark red foliage made a dramatic combination with brilliant scarlet flowers that resembled a candle flame at the top of the plant. Plants were around five foot tall and very uniform.

Celosia ‘Kelos® Fire Scarlet Improved from Beekenkamp

Deep burgundy foliage and flowers in small scarlet plumes made both a beautiful color and textural combination. Plants were compact and very uniform and made an impressive overall appearance.

Coleus ‘Under the Sea® Pink Reef’ from Hortcouture

Unique foliage was eye-catching because of a combination of a vibrant pink/rose leaf color and a very interesting leaf shape with ruffled edges. Foliage color held up well to sun without fading. Plants had controlled vigor and a nice dense canopy.

Combo ‘Kwik Kombo Shooting Star Mix’ from Syngenta

Dark purple angelonia were combined with golden yellow verbena that made a beautiful contrast of light and dark. With a little imagination, it resembles the stars in the night sky. The combination looked good both early and late in the season and never slowed down during the heat of the summer.

Dahlia ‘XXL Sunset’ from Dummen Orange

Huge blooms captured attention not only because of their size but also because of the beautiful coloring that included all the shades of the sunset. Plants were vigorous and did not have any mildew late in the season.

Geranium (Interspecific) ‘Calliope® Dark Red’ from Syngenta

Impressive overall visual effect was created by robust plants and abundant large flower heads with a dramatic dark shade of red. Intense color held strong even in the high light of Colorado. Growth habit was exceptionally uniform.

Geranium (Zonal) ‘Brocade Fire Night’ from Dummen Orange

Coral colored flowers appeared especially bright against the unusually dark foliage created by a heavy reverse zonation. Plants were very uniform and covered by flowers. Plant seemed to have a somewhat “old fashioned” look due to the single petals and smaller umbels. However, they had great flower power due to the abundant flowers.

Impatiens ‘Big Bounce™ Lilac from Selecta

This entry is a multi-year winner in this category due to its dependable vigorous plants which was continually covered in flowers throughout the growing season. The soft lavender colored flowers had an iridescent quality that really made them stand out. Plants had a perfect mounding growth habit.

Ipomoea ‘Sweet Caroline Bewitched After Midnight™’ from Proven Winners

Uniform plants had foliage of dark purple with shades of bronze that created mix of color for added interest. This variety stood out from the rest due to the large leaves that stood upright and a unique leaf shape which made it a plant to add texture in the landscape.

Lobelia ‘Suntory Lobelia Compact Blue’ from Suntory

This variety was impressive due to its ability to look great all season long. Most lobelias fade out in the heat mid-summer but this variety still maintained a dense mound of abundant medium blue flowers even into September. Growth habit was very compact and tight in addition to being very floriferous.

Marigold ‘Little Duck Orange’ from Ameriseed

Flowers were extra-large and the orange color “popped” against the dark green foliage. Plants had a compact growth habit with dense foliage and had a very uniform appearance.

New Guinea Impatiens ‘SunStanding Salmon’ from Dummen Orange

Despite the name, this variety had impressive flower power even in the shade. Salmon color flowers were very attractive and even looked good as they faded to white with age. They were vigorous plants which grew tall but had great uniformity.

Pentas ‘BeeBright™ Pink from Syngenta

Bright pink flowers had uniform flowering and were good for attracting pollinators. Plants liked the heat and tolerated the cool nights. Abundant flowering created a good overall appearance.

Petunia (Veg Mound) ‘Purple Sky’ from Dummen Orange

Plants were covered by a blanket of deep purple flowers that continued to bloom strong even into September. The floriferous plants had growth habits that were very uniform and showy.

Petunia (Veg Spread) ‘ColorRush™ Pink’ from Ball FloraPlant

‘ColorRush™ Pink’ broke through the heavy competition in this class to come out the winner in 2016. The large spreading plants were very uniform and covered with a deep pink flowers. Foliage was dark green but hard to see due to the solid canopy of flowers.

Petunia (Seed Spread) ‘Tidal Wave® Red Velour from PanAmerican Seed

Vigorous plants spread across the ground and had flowers with an impressive rich, burgundy red color. Blooms maintained deep color without fading. Plants were uniform and did not open up in the middle.

Portulaca ‘Colorblast Double Cherry’ from Westoff

Flowers were more scarlet than cherry colored but were still very showy with a double center. Plants were floriferous and very vigorous with a spreading growth habit. Flowers opened significantly earlier in the day compared to others in the trial.

Salvia ‘Mirage Cherry Red’ from Darwin Perennial

Prolific, bright cherry red flowers were large and made a great hummingbird attractant for the garden. Abundant branching made a very attractive, full plant. Plants maintained good growth habit.

Scaevola ‘Scalora™ Pearl’ from Westoff

Great vigor made this Scaevola the biggest in its class. White flowers were very numerous and showy. Flowering began early on in the season and kept well into September. It had a strong mounding habit that works well in baskets.

Sun Impatiens x hybrid ‘SunPatiens® Compact Coral Pink’ from Sakata

Beautiful soft coral colored flowers sat on top of the foliage for maximum visibility. Flowering was so abundant that foliage was barely visible but did show an attractive dark green that provided the perfect backdrop to the flowers. Plants were perfectly uniform and appeared to have no problem growing in full sun.

Verbena ‘EnduraScape™ Pink Bicolor’ from Ball FloraPlant

This entry out-performed all other Verbenas for continuous flowering throughout the season. The large pink and white bicolor flowers were very abundant and formed a very uniform blanket of color. Flower power was enhanced due to the blooms being held high above the foliage and plants were self-cleaning.

Vinca ‘Mega Bloom™ Polkadot’ from Ameriseed

This class had a lot of competition but this variety won out with great uniformity and large blooms. White flowers had a small pink eye giving it a “polkadot” effect which added interest. Plants were full and had a good foliage color.

Zinnia ‘Zahara® XL Fire Improved’ from PanAmerican Seed

Long lasting appeal was created not only because of the prolific flowering but it covered the plants from the top all the way to the bottom. Vibrant shades of orange and red had a nice fade to a softer orange. Uniform plants were low maintenance and required no dead heading as the new flowers seemed to “bury its dead”.

_____Other Outstanding Plants_______________________________

Angelonia ‘Archangel™ Cherry Red’ from Ball FloraPlant

The cherry red color marked the entry of a new color class for Angelonia. The unique color was also combined with extra-large flower spikes and dark foliage that contrasted nicely with the blooms. Plants were very healthy and uniform.

Geranium (Interspecific) ‘Caliente® Fire’ from Syngenta

This makes a great landscape plant but also looked amazing in the container. Impressive plant vigor and uniformity was second only to the prolific display of intense red flowers. Also, it was reported to do well even at 8,000’ altitude.

Lantana ‘Lucky Sunrise Rose’ from Ball FloraPlant

Another multi-year award winner, ‘Lucky Sunrise Rose’ was again impressive in 2016 with a great combination of bright colors and superior flowering. Plants had excellent, dense growth habits and great vigor. Flower color contrasted nicely with dark green foliage. It would be a good choice for either a basket or in the landscape.

Phlox ‘Gisele Hot Pink’ from Selecta

Not only did this plant survive in Colorado, it thrived and produced a mat of striking pink flowers. Growth habit was very dense and uniform. Flower color was vibrant with no fading.

Petunia Night Sky, Galaxy Petunia

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Petunia ‘Night Sky’ (Petunia ‘Night Sky’)

Botanical name

Petunia ‘Night Sky’

Other names

Petunia ‘Night Sky’, Petunia ‘NightSky’


Petunia Petunia

Variety or Cultivar

‘Night Sky’ _ ‘Night Sky’ is a vigorous, tender, mound-forming perennial, usually grown as a container or bedding annual, bearing ovate, sticky-hairy, dark grey-green leaves and velvety, white-flecked, dark purple flowers from late spring into autumn.




Cushion or Mound Forming

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Spotted, Dark-purple in Spring; Dark-purple, Spotted in Summer; Dark-purple, Spotted in Autumn

Grey-green in Spring; Grey-green in Summer; Grey-green in Autumn

How to care

Watch out for

Specific pests

Aphids , Glasshouse whitefly , Leaf-mining sawflies , Slugs , Snails

Specific diseases

Foot and root rot , Grey mould

General care



Propagation methods


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Where to grow

Petunia ‘Night Sky’ (Petunia ‘Night Sky’) will reach a height of 0.3m and a spread of 0.3m after 1-2 years.

Suggested uses

City, Cottage/Informal, Beds and borders, Containers


Grow in well-drained, light soil in a sheltered, sunny site. Plant out after the danger of frost has passed.

Soil type

Loamy, Sandy

Soil drainage

Moist but well-drained, Well-drained

Soil pH

Acid, Alkaline, Neutral


Full Sun


South, West



UK hardiness Note: We are working to update our ratings. Thanks for your patience.

Tender in frost (H3), Indoor heated (H1)

USDA zones

Zone 11, Zone 10, Zone 9

Defra’s Risk register #1

Plant name

Petunia ‘Night Sky’ (Petunia ‘Night Sky’)

Common pest name

; Black wood of grapevine; Female sterility of tobacco; Fruit woodiness of tomato; Maize Redness; Mal azul of tomato; Metabolbur; Metastolbur; Parastolbur; Purple top of potato; Stolbur of potato; Stolbur of tobacco; Stolbur of tomato

Scientific pest name

Candidatus Phytoplasma solani



Current status in UK


Likelihood to spread to UK (1 is very low – 5 is very high)

Impact (1 is very low – 5 is very high)

General biosecurity comments

Phytoplasma which potentially affects a wide host range; determined by the feeding behaviour of vectors. First UK outbreak in 2014; on strawberry; a host not specifically regulated in EU legislation. This legislation should be reviewed to take account of this and other developments.

Defra’s Risk register #2

Petunia ‘Night Sky’ (Petunia ‘Night Sky’)

Xiphinema bakeri



Nematode pest; could potentially affect trees and other species if introduced but many pathways regulated. No evidence of interceptions or findings to date.

Defra’s Risk register #3

Petunia ‘Night Sky’ (Petunia ‘Night Sky’)

Lance nematode; Nematode; Lance

Hoplolaimus spp.



Nematode species potentially affecting a wide variety of crops; prohibition of soil likely to mitigate risk substantially; keep under review in light of interceptions or findings should they occur in the EU.

About this section

Our plants are under greater threat than ever before. There is increasing movement of plants and other material traded from an increasing variety of sources. This increases the chances of exotic pests arriving with imported goods and travellers, as well as by natural means. Shoot is working with Defra to help members to do their part in preventing the introduction and spread of invasive risks.

Traveling or importing plants? Please read “Don’t risk it” advice here

Suspected outbreak?

Date updated: 7th March 2019 For more information visit:

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