Petunia Guide: How to Grow & Care for These Flowers

Our guide to Petunias for all you will ever need to know! Tips for planting, growing, and caring for Petunia flowers.

Do you have more room in your garden or home and you are currently looking for the perfect candidate to fill it? Say no more! Have a seat, relax, and let us guide you into the world of one of the best low-maintenance flowers out there – the Petunia.

Although the Petunia genus has only 20 species of flowering plants, you will have plenty of varieties and hybrids to choose from. Their flowers exhibit a wide range of hues and can also come in hypnotic colour mixes. Thanks to this, it is quite impossible not to find at least one specimen to your liking. And, just between us, it will be difficult to choose just one!

The versatility of Petunia plants will make them important additions to your plant collection. You can use these splendid flowers in any type of garden for colour masses, in beds and borders, or as groundcovers. They also work lovely in containers and hanging baskets both indoors and outdoors.

Ready to learn more about Petunias? Keep reading to find out how to grow and care for these low-maintenance flowers.

About Petunias

  • Prized for their gorgeous flowers, numerous cultivars have gained the Award of Garden Merit. Some of these are ‘Conblue’, ‘Conglow’, ‘Constraw’, ‘Kerpril’, ‘Storm Lavender’, ‘Storm Pink’, and ‘Sunpurple’.
  • Most of these plants sold nowadays in nurseries and markets are hybrids. The most common Petunias among growers include Petunia × atkinsiana, ‘Blue Spark Cascadia’, ‘Prism Sunshine’, and ‘Supertunia Silver’.
  • The Inca and Maya people believed that the fragrance of Petunia flowers had mystic value. They used a magical drink obtained from their flower buds to ward off underworld spirits and monsters.
  • Gifting Petunia plants to someone can mean two different things in the language of flowers. It can symbolize either resentment/anger or that the giver is comfortable with that particular person.
  • According to New Age folklore, these plants will only perform best in places filled with positive energy and lose their splendour in environments where negativity floats.
  • Petunias make for excellent companions to other species of plants, such as African Daisy, Allium, Black-eyed Susan, Lupine, Iris, Mealy Cup Sage, Rose, Snapdragon, Verbena, or Zonal Geranium.
  • They have no toxic effects on humans or animals if touched or ingested. You can grow Petunias absolutely anywhere around your house without worrying about the safety of your beloved ones.

Petunia Features: An Overview

  • Petunias belong to the Solanaceae family of flowering plants. They share this family with popular plants including Angel’s Trumpet, Belladona, Groundcherry, Nightshade, Pepper, and Tobacco.
  • Most Petunia species are technically herbaceous perennials, but many grow them as annuals. These plants can have either mounding or cascading growth habits.
  • Depending on the variety, they can reach from 6 to 24 inches (15-61 cm) in height and up to 36 inches (91 cm) in width.
  • Their foliage consists of sessile, oval-shaped, and green leaves that grow on long, thick stems. Both leaves and stems can sometimes have fine sticky hairs.
  • In general, they bloom during the summer months. In temperate climates, this period can last much longer, usually from spring through fall. There are single- or double-flowered Petunia varieties.
  • Their delicate, trumpet-shaped blossoms have five fused or partially fused petals and five green sepals. They come in various tints of red, pink, orange, yellow, purple, orange, green, or numerous vibrant colour combinations.
  • Petunia plants bear fruits known as capsules when their flowering period has ended. The capsules are dry and split open when ripe to release seeds.

Growing Petunias

Petunia plants are so irresistible and versatile that they can make great additions to any type of garden. These flowers work their way into their future owners’ hearts by having very few demands when it comes to their growing conditions. Still, you must pay attention to some specific details if you want to see them thrive. After all, when their flowers look so adorable, it is only natural to want them around for as long as possible!

Most Petunia cultivars do well if you provide them with plenty of bright and direct light. In outdoor settings, you should plant them in a spot where they can receive at least six hours of full sunlight each day. During the hot summer months, your plants will appreciate partial shade more, especially in afternoons with harsh sunlight. Indoors, keep these flowers in a well-lit area.

2000 Pcs Mixed Petunia Seeds, From Amazon

In terms of temperatures, Petunias usually prefer those climates from the warmer zones. These plants perform best in daytime temperatures that range from 60 to 75 °F (16-21 °C) and 55 to 65 °F (13-18 °C) at night. They can also withstand temperatures that drop to 40 °F (4 °C) or so, but freezing conditions or frost can damage them irreversibly.

In general, Petunia flowers do not encounter any serious problems with diseases or pests. If you are growing them in improper conditions, however, things may get a bit troublesome. They become susceptible to fungal diseases like grey mold and various pests including budworm caterpillars and aphids.

The best way to avoid these issues is to look for Petunia varieties that have a higher tolerance to moisture. In cases with fungal diseases, you must remove the infected parts from your plants and apply a suitable fungicide. If you notice any suspect presence on their foliage, you can handpick the intruders or spray them off your plants. For severe infestations, you should also use an insecticide.

Planting Petunias

Petunias are not very picky regarding their growing medium. Typically, these plants prefer light and fertile substrates with a slightly acidic soil pH. Yet, they can grow just fine in a wide range of soils as long as they have excelent drainage properties.

Plant your Petunia flowers in spring when you are sure that the danger of winter frost has passed. At the time of planting, make sure you apply a balanced fertilizer to your baby Petunias. These plants will also benefit from regular fertilizing from July through autumn. During this period, feed your plants with a liquid fertilizer designed for flowering plants once every two weeks.

You can encourage more branching and a fuller overall look by pinching the stems of your Petunias back. Depending on the age and size of your plants, this process will be different from one specimen to another. If you have short seedlings, you have to pinch them an inch (2.5 cm) or less. For gangly seedlings or mature plants, you can pinch the stems back by half.

Although younger Petunias do not require deadheading, many varieties will bloom more profusely if you are doing it once in a while. Older Petunia plants, however, will need regular deadheading to keep them in bloom. During their flowering season, remove the spent blossoms to allow new ones to flourish.

Watering Petunias

Petunias are flowering plants that do not appreciate dry conditions for too long. On the other hand, they can become victims of root rot if you provide them with too much water. But you don’t need to worry, the process of watering these flowers is not as hard as you would imagine.

In general, Petunia plants get the needed amount of water from regular rainfalls. In regions with seldom rainfalls, these flowers will grow at their best with weekly watering. In addition to that, potted plants or spreading varieties will require more frequent watering than usual.

For an optimal watering routine, make sure you do not allow their soil to dry out more than two inches (5 cm) deep. If your Petunias grow somewhat leggy and produce very few flowers, this may be a sign that you are giving them too much water. When it comes to humidity, low to moderate levels are ideal for Petunia plants.

Pink and violet Petunia
Pink and violet Petunia

Propagating Petunias

Luckily you can already purchase young Petunias from nurseries and be all safe and happy. But every gardener secretly dreams to try their hands at propagating although it can be a bit of a challenge. If you want to spice things up in your garden, starting Petunia plants from seed can surely bring you this kind of excitement! This is a good propagation method if you also want to obtain a particular variety.

For the best growth, it is mandatory to propagate Petunia plants through seeds at the right time. Typically, you should sow the seeds about 10 to 12 weeks before the last sign of frost in your region. If you are doing this properly, the seedlings will have enough time to develop until spring.

First things first, sow your Petunia seeds above a moist seed-starting mix. Make sure you do not cover them with soil because they will need lots of indirect sunlight to show nice results. Secondly, cover the container with a clear plastic wrap and place it in a well-lit, warm area. After one week or so, when you notice tiny seedlings emerging, you can remove the plastic for good.

Provide your Petunia seedlings with water regularly to maintain their soil slightly damp. Once they have produced 3-4 leaves, you can transplant them in their permanent locations. However, do not forget to save some potted babies for your special family members or friends!

In Conclusion

Petunias have all it takes to be your next ornamental buddy. Not only do these plants look absolutely fabulous, but they are also very easy-going with their owners and other companion plants. Once you find a cultivar (or more) that is to your liking, you can start to fill your garden with beautiful flowers!

Are you already growing Petunias in your garden? Share your experience in the comments below!

Miruna is an experienced content writer with a passion for gardening. She is the proud owner of an outdoor rose garden and an indoor collection of tiny succulents. She bought her first succulent 10 years ago - an adorable Echeveria Setosa. Now she owns more than 100 succulents and cacti of different colors, shapes, and sizes. Miruna is a versatile writer and, as you might have guessed, her favorite topic is gardening. Contact

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