How to Grow Petunias? Petunia Care Guide

Grow petunias is a fun and easy way to add some green to your garden. Petunias are easy to care for, and they make a great addition to any garden.

Petunias is a genus of subshrubs and herbaceous perennials. There are members of the Solanaceae family in this genus. These plants are found naturally in the wild in the tropics of Argentina, Uruguay, Brazil, Bolivia, and Paraguay. The Brazilian word “petun,” meaning “tobacco,” inspired the naming of this species.

Tobacco and petunia are actually closely related plants. One species of petunia can be found even on the North American continent. In total, there are about 25 different species in this genus. Some of these species have a great deal of diversity among them. Since the 18th century, this type of plant has been used ceremonially. More than a century ago, plant breeders worked to generate hybrids that are now often used as annuals in home gardens and on balconies.

Petunia is appealing because it blooms profusely and continuously throughout the season, and its flowers are quite large, bright, and gorgeous. Furthermore, this plant complements other garden blooms, such as begonias and pelargoniums.

Hanging arrangements of ampelous petunia, especially those that have a rainbow of hues, are a sight to behold. This plant’s widespread appeal also stems from the fact that it can be grown successfully by even the most green-thumb-challenged grower.

How to Care and Grow Petunias?

Brief description of cultivation

When? Planting in the ground in the second half of May from seedlings sown at the end of February or the second half of March.
Light. Radiant sunshine.
Soil. Rich, compost- or humus-enhanced soils, whether sandy or loamy.
Water. In a dry season, you should water the roots deeply.
Fertilizer. The first fertilizer application is made a week after planting, and further applications are made every 10 days. It’s August now, so you can stop feeding your pet.
Propagation. Techniques involving seeds and cuttings are described.
Pests. Slugs, snails, aphids, and thrips.
Diseases include late blight, chlorosis, gray rot, and black leg.

Petunia Features

The petunia has a bushy form. Such a bloom can be anywhere between 0.15 and 0.7 m tall, with upright or creeping stems that are highly branched. The 5-12 centimeter-long, alternately placed, entire oval leaf plates are a dark green or green tint.

The surface of the leaves and stems becomes covered with pubescence. Short peduncles support singular, funnel-shaped blossoms that may be terminal, axillary, irregular, double, plain, or fringed. Flowers can have a variety of colors and patterns, including a border, a white star, a halo, or black veins. The seeded fruit resembles a bivalve-shaped box.

Axillary petunia and purple petunia, two wild species, were used in the breeding of garden petunia (hybrid) types, which are now often grown on patios and in backyard gardens. The flowers bloom from July till the first frost.

The petunia has a bushy form. Such a bloom can be anywhere between 0.15 and 0.7 m tall, with upright or creeping stems that are highly branched. The 5-12 centimeter-long, alternately placed, entire oval leaf plates are a dark green or green tint. The surface of the leaves and stems becomes covered with pubescence. Short peduncles support singular, funnel-shaped blossoms that may be terminal, axillary, irregular, double, plain, or fringed. Flowers can have a variety of colors and patterns, including a border, a white star, a halo, or black veins. The seeded fruit resembles a bivalve-shaped box.

Axillary petunia and purple petunia, two wild species, were used in the breeding of garden petunia (hybrid) types, which are now often grown on patios and in backyard gardens. The flowers bloom from July till the first frost. Growing petunias is an annual standard practice.

The petunia has a bushy form. Such a bloom can be anywhere between 0.15 and 0.7 m tall, with upright or creeping stems that are highly branched. The 5-12 centimeter-long, alternately placed, entire oval leaf plates are a dark green or green tint. The surface of the leaves and stems becomes covered with pubescence. Short peduncles support singular, funnel-shaped blossoms that may be terminal, axillary, irregular, double, plain, or fringed. Flowers can have a variety of colors and patterns, including a border, a white star, a halo, or black veins. The seeded fruit resembles a bivalve-shaped box.

Axillary petunia and purple petunia, two wild species, were used in the breeding of garden petunia (hybrid) types, which are now often grown on patios and in backyard gardens. The flowers bloom from July till the first frost. Growing petunias is an annual standard practice.

The petunia has a bushy form. Such a bloom can be anywhere between 0.15 and 0.7 m tall, with upright or creeping stems that are highly branched. The 5-12 centimeter-long, alternately placed, entire oval leaf plates are a dark green or green tint. The surface of the leaves and stems becomes covered with pubescence. Short peduncles support singular, funnel-shaped blossoms that may be terminal, axillary, irregular, double, plain, or fringed. Flowers can have a variety of colors and patterns, including a border, a white star, a halo, or black veins. The seeded fruit resembles a bivalve-shaped box.

Axillary petunia and purple petunia, two wild species, were used in the breeding of garden petunia (hybrid) types, which are now often grown on patios and in backyard gardens. The flowers bloom from July till the first frost. Growing petunias is an annual standard practice.

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Growing petunias from seeds

1. Sowing

Planting petunia seeds in February will necessitate a backlight to ensure the success of the young plants. Most gardeners prefer to plant seeds around the middle to the latter part of March, but it’s important to remember that germination rates are quite low at this time of year because of the short days. The ideal sowing medium is one that is airy, porous, and rich in nutrients. Substrate ingredients should include composted humus, peat moss, sand, sod, or leafy soil (2:2:1:2).

The soil combination should fill the container, with the sifted substrate forming the top 10 mm. The soil mixture needs to be watered well for at least 24 hours prior to sowing, after which the seeds can be spread out uniformly across its surface. Before planting, seeds should be mixed with dry sand. Following this, a spray cannon is used to evenly wet the substrate’s surface. It’s important to use something like a film or glass to cover the top of the container. The crops are picked at a warm (between 20 and 23 degrees) location.

The first sprouts should show in about 7 days. Every day, twice a day, you must open the windows and mist them with water. Keeping the mini-air greenhouse’s humidity high during this time is crucial, but doing so may cause the plants to develop a blight known as “black leg.” Condensation on the film can be avoided by flipping the glass over every day as soon as it forms and wiping it clean.

Finally, a mild solution of potassium permanganate should be sprinkled on seedlings on a regular basis. At the point when the first true leaf plate appears on the plants, the container can be removed, a thin layer of sand can be spread over the surface of the substrate, and watering can be reduced.

2. Seedling Care

The seedlings should be harvested when they have three or four true leaf plates, but not before the substrate in the container has been properly wetted. The plant can be gently pried apart with a stick. Holding the leaves, carefully pull them out of the soil, taking care not to disturb the substrate or the plant’s roots. Picking takes place from containers of the same type and size, typically plastic or peat moss. The plants need to be well watered and covered with paper sheets or lutrasil for two to three days after harvesting.

For the next few weeks, seedlings need special attention and care. The substrate should be kept at a consistent moderate moistness during this time. In one scenario, the seedlings will need to be soaked once or twice a week, while in the other, they’ll need to be soaked twice a day. This variation in watering needs is due to the fact that different factors influence the frequency of irrigation at different stages of plant growth. It’s crucial to routinely break up the soil around the plants.

The plant needs to be fed once per week, 7 days after harvesting, alternating between root and foliar feeding. Top-dressing with 25–35 grams of water-soluble complex fertilizer per 1 bucket of water can be done with Kemira, Nitrofoska, Mortar, or any other similar product.

It takes three months for Grandiflora kinds to bloom after planting seeds, and just two and a half months for multiflora. Hardening off is necessary prior to plant seedlings in open soil. This is accomplished by either placing the seedlings in the street during the day or relocating them to a cool area for a few days

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Planting petunias in open ground

What time to plant?

Soil that is either sandy or loamy Petunias thrive in loamy, fertile soil that has been amended with humus or compost shortly before planting. Manure should not be used as a fertilizer since it can promote the growth of fungi that cause plant illnesses. An open, well-lit location is ideal for planting. When there is no chance of frost in the spring, seedlings can be planted (usually from mid to late May). The best time to land is at night or on a rainy day.

Landing Features

Petunias of this variety will bloom from the time they are planted as seedlings until November. These flowers are typically planted near the border of a garden because of their height. After giving potted flowers a good soaking, you can remove them from their containers and plant them in a freshly dug hole. Maintain a minimum of 0.3 m and a maximum of 0.4 m of open space between plants. Flowers need to be watered after planting. A day later, a layer of mulch had been spread on the ground at the site.

Petunia care in the garden

It’s not hard to tend a petunia garden, but you should familiarize yourself with the rules and specifics of doing so before you start planting. However, petunias still require regular watering throughout the hot summer months, despite their resistance to drought. It’s important to remember that smaller-flowered cultivars require less watering than their larger-flowered counterparts. The plant’s fragile blossoms can be damaged if water isn’t placed under the root during irrigation. The next day after watering the petunias, the area needs to be loosened up while all weed grass is removed.

You should consistently feed this plant if you want it to bloom for a long time and well. Petunias require their initial feeding seven days after being planted in the ground. Then, from then until August, complex fertilizer with a lot of potassium is used as top dressing once every 1.5 weeks. Petunias benefit from occasional feedings of organic fertilizers such as humic fertilizers and mullein infusions.

Propagation of petunias by cuttings

Only terry and ampelous petunias, as well as all mini-petunia groupings, are suited to propagation via cuttings (calibrachoa). Cuttings of terry types can be started in the final weeks of winter or the first weeks of spring, while those of mini-petunias and ampelous ones can be started at any time of year so long as they are provided with sufficient light (from fluorescent lamps) and warmth (from 21 to 24 degrees).

The apical cuts should contain four to six leaflets and should be removed. Remove everything but the top two leaves by tearing them off. Reduce the length of the remaining leaves by half. When rooting cuttings, use the same potting soil mixture that is used for seeds. However, in this instance, a layer of perlite or sand 20-25 mm thick, which must be shed with a fungicide solution, should be spread across the surface of the substrate.

The cuttings must be separated by at least 15 to 20 millimeters, and the top of the container is covered with glass. Because newly cut cuttings take root so well, you don’t need to employ growth-promoting substances like Heteroauxin. However, you shouldn’t wait to plant them either. The substrate in the greenhouse should be kept slightly damp at all times; this can be accomplished by spraying the petunia twice a day. Blackleg, or mold, can develop if there is too much moisture in the air. Mini petunias will take around 7 days to properly root, whereas Terry and ampelous petunias will take about 14 days.

Roots should be 10-15 mm in length before repotting into 50 mm-diameter pots. Pinching the plant above the fourth or fifth leaf plate encourages a fuller bushing growth habit. After pinching, the stems’ upper portions can be used as cuttings. If the stems still need it after a month, pinch them again. At the end of the first six weeks, the seedlings are transplanted into larger containers (11 to 13 centimeters in diameter).

Growing cuttings require practically identical treatment to that of seedlings. Keep in mind though that ampelous petunias and mini-petunias need a lot of breathing room, therefore hanging containers are the best option for growing them.

Diseases and pests

If the proper agricultural practices for cultivating petunias are followed, the flowers will never become sick and pests won’t settle in. Late blight, chlorosis, black leg, and gray rot are just a few of the illnesses that might strike an unattended plant. In order to successfully combat these illnesses, specialized equipment is required. However, illnesses can be avoided with regular shrub maintenance. Even viral infections that are currently incurable can be affected by this plant.

Petunias are susceptible to pests like aphids, thrips, spider mites, and slugs. You can get rid of them, but you need to utilize medications that are made specifically for this purpose.

Seed collection

The seeds should be harvested only when they have reached full maturity on the plant. Take note of the flowering bushes of the types whose seeds you’ll need to collect. It is important to remember that seeds are harvested from the lower buds, where they develop and ripen more rapidly. It takes around 8 weeks from the time the bud is fully formed for the seeds within it to reach full maturity. There are roughly one hundred of these tiny (roughly a half millimeter in diameter) seeds in a box.

Distribute the ripened seeds by shaking them out of the boxes and into bags; then, be sure to record the collecting year, flower kind, and color on the bags. There’s no need to bring the long boxes into the house with you when you can just trim them down to size. Ripening seeds requires keeping them at room temperature for three to four months. The seeds have a four-year shelf life if stored properly.

After flowering

The petunia bush should be dug up in October and have all of its shoots cut off if you intend to keep it. The bush is potted and cared for in a cool environment. The bloom will rest here, but it will need regular watering to keep the soil at a comfortable level of dampness. In February, a plant in a pot should be moved to a bright, warm window sill and its regular watering schedule resumed. A “heel” is used to remove the first two or three pairs of leaves from young stems before they are planted in flowerpots with nutritional soil and a layer of sand on top.

Glass or film must be used to cover the container before it is moved to a tiny shade. Maintain consistent watering, spraying, and airing for the plants for 20 days, or until the shoots begin to develop roots. The next step is to transfer the plant to individual containers. They join the petunia seedlings in being placed in the open soil.

In the fall, it’s important to clear the area of any dead petunia bushes and burn or bury them.

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Types and varieties of petunias

Large-flowered and multi-flowered types are the two broad categories into which all garden petunias fall.

1. Multi-flowered petunias (Multiflora)

Compared with large-flowered varieties, multi-flowered (multiflora) begin to bloom earlier, while many flowers grow on the bush, having a five-centimeter diameter, they bloom for a relatively long time. Such flowers are picky, they can be grown in any soil, they are not afraid of rain and like sunlight. In this regard, such a petunia can be called a real garden flower. It looks less impressive than plants of large-flowered varieties, but compact bushes covered with flowers of various shades are able to delight with their beauty before the onset of severe frosts. The following varieties of petunia multiflora are the most popular:

1. Speculative writings. There are a total of 9 unique hybrids in this set. The plants grow to a height and width of about 0.2 m, and their blossoms can range in color from red with white veins and a whitish neck to salmon, raspberry red, pale salmon with dark veins, raspberry pink, blue-purple, white, pale pink with a cream throat, and so on.
2. A figment of your imagination. There are a total of 13 small hybrids in this set. Double flowers range in size from 60 to 90 mm and come in a wide variety of colors and patterns, including red with burgundy veins, raspberry-burgundy, lilac-pink with purple veins, pink with raspberry-red veins, white, and more.
3. Plume crystals. The shrub can grow to a height of 0.3 m and a width of 0.25 m. Its flowers measure about 70 millimeters across. The blossoms begin as a lilac-pink tint but gradually fade to a lighter shade of lilac before finally becoming nearly colorless. Veins painted in a burgundy-violet color stand out vividly against the flower’s background.

2. Large-flowered petunia (Grandiflora)

The large-flowered petunia hybrids are the most popular type and they come in hundreds of different variations (Grandiflora). The blooms on such plants are enormous and spectacular, but they are far less numerous than those on small-flowered types. However, there is one drawback to this group: flowers that have been damaged by wind and rain lose their beauty and become less appealing to the eye. Because of this, large-flowered petunias are typically grown indoors in pots or containers on a balcony or terrace. There are several subsets within this group:

1. large-flowered, in which the bush grows to a height of 0.6 m and the flowers’ smooth diameter is 8 to 10 cm; large-flowered low, in which the bush grows to a height of 0.25 to 0.3 m and shares the same other features as the former group;
2. Its flowers are about 12 centimeters in diameter; the bushes grow to a height of 0.25-0.3 m and 0.65-0.7 m, respectively;
3. Large-flowered Superb and Large-flowered Superb Low have bush heights of 0.3-0.4 m and 0.5-0.75 m, respectively; their smooth blooms have a wide throat; their diameter is around 10-12 centimeters, and their surface is veined with a darker hue compared to the primary backdrop;
4. Depending on the cultivar, large-flowered terry can have bushes as tall as 0.6 m and enormous, double flowers as wide as 10–12 cm, with either a fringed or smooth petal edge.

The following series of large-flowered petunias are very popular:

1. Famous songs played repeatedly. They bloom rapidly since they are hybrids. The bush is roughly 0.25 meters in height. There is a wide range of possible flower paint colors, including red, blue with a white star, violet-blue, pink, white, salmon, etc.
2. To be precise, Pikoti. This group of four hybrids is distinguished by its unusually wavy petal edges; the white border on these flowers can be as wide as 15 mm. The tallest part of the bush is 0.25 meters. There are violet, blue, red, pink, and crimson hues used to paint the blossoms.
3. Pirouette in purple. This purple-violet terry mix has a white border along the fringed edge of the corrugated petals. The shrub is 0.25 meters in height.

3. Petunia Floribunda

Petunia floribunda is still in high demand, in addition to these more mainstream types of petunias. In this sense, it lies somewhere in the middle of the two categories. This group’s flowers are virtually as unfazed by wet weather as petunia’s many-flowered flowers. The beauty of such plants, however, comes from their bulk cultivation in expansive flower beds. Varieties:

1. Sonia. There are eleven different hybrids in this series, and they are all huge hits with gardeners. The highest bush is 0.25 m in height. You can paint your flowers any color you like, from red to burgundy red with a white star, white to pale purple with purple veins, pink to rosy red with a white star, red to red with a white border, etc.
2. Famous person. The hybrids in this series can withstand high temperatures and heavy downpours. The flowers in this series come in a wide range of color combinations, with some having as many as three different hues.

4. Milliflora Petunias

Milliflora petunias are far more compact than any other kind of petunia now available. Although the flowers are just 1 to 1 1/2 inches across, there are a lot of them and they endure the whole season.

5. Spreading or Trailing Petunias

These are slow-growing plants that can reach a width of up to three or four feet. So because flowers grow along the whole length of each stalk, they create a gorgeous ground cover that is full of vibrant colors. They are versatile enough to be utilized in hanging baskets as well as window boxes.

Frequently Asked Questions About Petunias

Can petunias grow in shade?

Although petunias flourish in full, direct sunshine, they may also tolerate partial shade. They can survive the winter in USDA zones 10 and 11, although even then they are often treated as annuals.

Do petunias attract hummingbirds?

Hummingbirds are attracted to tubular, brightly colored blooms because they generate the most nectar. Many annuals, such as petunias, impatiens, and cleomes, as well as many biennials and perennials like bee balms, dendrobiums, daylilies, and lupines.

Do deer eat petunia?

Petunias, on the other hand, are susceptible to being eaten by deer. Deer, just as they do with any other type of succulent, will sniff out your petunias and promptly make the decision to consume them.

What causes the yellowing of my petunia leaves?

Petunias frequently develop a yellow tinge because of improper planting, insufficient exposure to sunlight, inadequate drainage in the soil, or an absence of fertilizer. Another symptom of tobacco mosaic virus infection is a yellowing of the leaves.

What causes my petunias to stick?

Petunias produce a sticky substance that escapes through the tissues of its stems. In its turn, the sticky substance makes its way all the way to their delicate leaf. According to the research conducted by the Utah State University Extension, the goo is thought to provide protection against pest insects like as thrips and aphids.

Do bees like petunias?

Petunias are bee-friendly because bees pollinate flowers in their colonies. Bees adore floral nectar and pollen. Petunias are ideal for bees because their finely split petals gather nourishing honeydew.

What amount of light do petunias require?

Petunias need about 3-4 hours of sunlight each day in order to thrive. This is depending on the location where the petunias are grown, and can also vary depending on the time of year. Petunias should be kept in a sunny spot when grown, as they will not flower until they get some light in their life.

Do squirrels eat petunias?

Petunia flowers are very pleasing, and the spicy-sweet ones can even be eaten. The most likely culprits are squirrels. Unfortunately, no amount of effort put forth to deter a squirrel from eating them will be successful.

Petunias: Are they poisonous to humans?

Ingestion of any component of a Petunia plant will have no negative effects. There is zero evidence that handling any part of a Petunia plant would result in a skin reaction. When planting flowers outside, consider using petunias in locations where kids could play.