One of the most popular summer bedding plants in our region is the petunia, which blooms from mid-summer until the first hard frosts of autumn. Their profusion of flowers fills gardens with wonderful color.
The trailing kinds liven up hanging baskets and flow down the edges of containers, while the compact, bushy varieties are ideal for planting in beds and borders.
Petunia flowers come in a vast array of colors, single and double blooms, smooth or ruffled petals, solid single, striped, veined, or picotee-edged colors, and even fragrance. The issue of ancient petunia types turning to mush in a wet summer has also been eradicated by recent breeding.
Petunias are perennial, despite the fact that the majority of bedding kinds are produced from seed annually as annuals. The perennial trailing varieties, like Surfinias, are cultivated from cuttings or young plants.
Cultivation
Although they will tolerate a little moderate shade during the hot, sunny summers, petunias like to be cultivated in full sun. They thrive on soil that is rich in nutrients, moist but well-drained. To keep moisture in sandy soils that drain very well, add lots of organic matter to the soil, such as garden compost, well-rotted manure, or other soil-improving materials.
Petunia varieties
Grandifloras, which have larger flowers, or multifloras, which have smaller flowers and are more resilient to rain, are the two varieties used as bedding.
The Surfinia, Wave, Tumbelina, Supertunia, and Cascadia series of petunias spread or trail.
Sowing petunias
Petunias can be grown from seeds inside with warmth in cell trays, seed trays, or tiny pots at a temperature of 18 to 24C as an annual or bedding plant (65-75F).
When plants are big enough to handle, prick them out into cell trays or tiny pots and let them continue to grow at a temperature of 50 to 65 degrees Fahrenheit (10 to 15 degrees Celsius) in good light.
Before planting the seedlings outdoors once all danger of frost has passed, gradually acclimate them to outdoor circumstances for 7 to 10 days.
Young petunia seedlings are available from garden centers and mail-order suppliers in the late winter/early spring if you don’t have the resources to grow them from seed.
Planting petunias
Make a good-sized planting hole that can readily fit the rootball. Fork in a layer of organic material, such as compost or planting compost, at the bottom of the hole.
Place the rootball in the planting hole, adjusting the planting depth (except for hardy fuchsias) until the top of the roots is level with the soil surface and the rootball is planted at the same depth as it was growing. Fill the planting hole with the excavated soil after adding more organic matter to it. Put some granular general feed on the soil and thoroughly wet it in. The soil can be kept moist and weeds can be controlled by adding a 5-7.5cm (2-3in) deep mulch of well-rotted garden compost or something similar over the soil. If you have a warm greenhouse, you can plant baskets and containers in the spring, let the plants mature, and then move them outside in late May or early June. You’ll have flowers earlier in the summer if you do this.
How to care for petunias
When there are protracted dry spells in the summer, water the soil frequently to keep it moist. Plants in containers will require routine, possibly daily watering with the intention of maintaining evenly moist compost. But be careful not to overwater, as this may make the plants leggy and produce few blossoms.
To ensure a steady supply of blossoms throughout the summer, feed your plants with a liquid plant food on a regular basis. Up to the first autumnal frosts, a high potash liquid plant feeding will promote more, better blooms.
The show will last longer if faded blooms and any sprouting seed pods are removed. Cut back straggly plants severely before feeding them with a liquid plant food to encourage fresh new growth and an abundance of blossoms.
Fall is the greatest time to dig up and compost bedding petunias that have been harmed by frost.
Overwintering petunias
Trailing perennial kinds can be pruned back severely in the fall, cleaned up by removing any dead or broken growth, and then gently lifted. They should be overwintered in a bright, frost-free location, preferably a greenhouse or cool conservatory, in pots just large enough to hold the rootball and with some fresh potting compost around the sides.
Propagating perennial petunias
Cuttings taken in March or April from plants that overwintered or in August or early September from perennial, trailing kinds can be used to create new plants.
Select young, robust, vigorous stems that aren’t in bloom. Cut back one or two stems at the back of the plants severely to promote vigorous regeneration if you are unable to locate adequate growth. collect clippings 7.5–10 cm (3–4 in) long and positioned immediately below the node or junction of a leaf. In pots of gritted cuttings compost, place five or six cuttings at the base of the lowest leaves after removing the leaves from the lower two-thirds of the stem. Put the pots in a propagator or a plastic bag and set them somewhere with good light—but not in the sun—to root.
In two to three weeks, the cuttings should have taken, at which point they can be potted up separately and continued to grow.
How are potted petunias maintained?
Care for petunia containers is quite simple. Petunias are very hot and dry resilient, but soil in pots is prone to heating up and drying out much faster than dirt in a garden. While this doesn’t suggest you should ignore your petunias, you should let the soil totally dry out in between waterings.
Give them a long, slow drink every several days. Water either from below or close to the soil’s surface as wetting the blooms and leaves might lead to illness. However, you also don’t want to waterlog your roots, so make sure your container has excellent drainage.
Petunias consume a lot of food. When planting, use a slow-release fertilizer. Then, every two weeks or so during the season, follow up with a liquid fertilizer.
Put your containers in a spot with direct sunlight.
For the most abundant blooms, eight hours a day are preferred to six.
In hanging baskets, how long do petunias last?
Please note that some of the links on this page may be affiliate links. I may receive a commission if you click an affiliate link and buy something. I make money from qualifying purchases as an Amazon Associate. —
To answer the first portion of your question, petunias can live for two or three years, but they typically behave like annuals because they can’t withstand the harsh winter weather. See more below on that.
It’s challenging to accurately assign a timeline to each particular blossom in the second part. Despite the fact that they don’t have a long lifespan, the plant produces so many of them that you might not even notice.
If you prune petunias, will they grow back?
Petunia legginess can be avoided with diligence and consideration. To begin with, remember to keep your petunias moist. You might need to water petunias every day if you have them in a smaller container or basket. Make it a routine to check their moisture level each morning and to give them plenty of water to drink. You might need to water your petunias every three to five days if they are planted in the ground.
We are all aware that petunias bloom most profusely when the spent flowers are frequently deadheaded. But just plucking the petals is insufficient. If you want to learn how to stop petunias from growing too long, you must also remove the seed. At the base of what appears to be five slender green leaves arranged in a star-like configuration, the seed pod resembles a little green (or tan, if it is mature) chocolate chip. Cut or remove this blossom by snipping it.
Have you ever thought, “How can I get my petunias to grow bigger?” You must regularly trim the branches back by a quarter or a half to prevent lanky petunias. Since your petunia plant might be in full flower when you do this, it might be challenging. All of the branches can be pruned at once. In a few weeks, you will have a full, compact blooming petunia plant.
You can also prune just a few of the branches that are dispersed uniformly across the plant (by 1/4 or 1/2). Two weeks later, you can prune the remaining branches after those branches recover and rebloom. Maintain this cycle throughout the growing season to get the benefits of a full appearance and an abundance of beautiful petunia flowers.
Why are my petunias in pots dying?
Petunias are delicate annual flowering plants that die back in the winter because they cannot withstand frost or freezing temperatures.
Petunias that are dying and drooping typically have fungal infections such root rot, which are brought on by an excessive amount of moisture surrounding the roots. Petunias require thorough watering once a week and cannot take soggy soil from over watering, which kills the plants by causing wilting of the leaves and blooms.
To avoid root rot or drought stress, it’s critical to strike the appropriate balance between watering and soil moisture in order to prevent petunias from dying.
Continue reading to find out the best ways to take care of petunias to keep them from dying and how to revive them so they can bloom again.
How do you take care of petunias in a hanging basket?
Hanging baskets will require more regular maintenance because water and nutrients leak out of them more quickly than for plants in the ground.
How do you keep petunia baskets blooming?
Petunias consume a lot of food. To encourage additional blooms, add a water-soluble fertilizer with a higher concentration of phosphorus and potassium to the slow-release fertilizer you applied when you were planting. Many contemporary hybrids are self-cleaning, unlike older kinds that need deadheading for ongoing flowering.
How many petunias are in one hanging basket?
It depends on the size of the basket and the plants’ mature size. Use four to six starter plants in 4-inch pots for a 12 to 14-inch basket.
How often to water a petunia hanging basket?
The best water for petunias is constant water. Checking hanging baskets periodically is necessary since they dry out rapidly. It’s time to water if the soil feels dry 1-2 inches down. This can include watering once or twice each day during warm weather. Reduce water use and avoid letting the soil become moist in cooler temperatures.
Does Miracle Grow work well with petunias?
Bigger, more beautiful plants are ensured with Miracle-Gro Water Soluble All Purpose Plant Food! It is packed with nutrients that are necessary for the happiness and health of your petunias. Every 7 to 14 days, this fertilizer is supposed to be administered.
People who have used this fertilizer claim that it completely revived their plants in just a few days. Some customers claim that a small amount is effective and that their plants adore it.
Should petunias be deadheaded?
Yes, deadheading is required for the majority of petunia varieties. Knowing how to deadhead petunias and remove them is a simple method to maintain your yard looking verdant and lovely. No one likes to look out into a landscape full of dead blossoms. Additionally, by removing the dead blooms, you prevent the plant from focusing its energy on producing seeds and instead encourage the growth of new blossoms, ensuring that your displays stay magnificent all summer long.
Deadheading is not necessary for supertunias or the slightly more resilient wave petunias. Wave Petunias continue to flower vigorously even without deadheading, but Kristin Winterbottom from Park Seeds advises removing faded blossoms to enhance the plant’s beauty (opens in new tab).
Do petunias like shade or the sun?
Petunias require at least 5 to 6 hours of adequate sunlight, and they thrive in locations that receive full sun all day.
While soil doesn’t have to be incredibly rich to produce good petunias, it does need to drain well.
It’s always beneficial to condition garden soil with organic matter, such peat moss, compost, or manure.
Use a rototiller or garden fork to incorporate it into the soil 8 to 10 inches deep.
increases the capacity of light, sandy soil to hold moisture and nutrients while also aiding in the opening up of heavy clay soil, which enhances drainage.
Can petunias be overwatered?
Why do they wilt in my garden, even though they appear attractive in nursery boxes and catalogs and bloom profusely in Palm Springs? I started pondering petunias because they puzzle me.
Beginning my enquiry, Kim Bodger of Bodger Seed Co. described how petunias evolved from tiny multiflora varieties in the 1950s to enormous grandiflora blooms in the 1960s and 1970s.
Petunias that blossomed quickly and in large quantities were bred by breeders to feed the bedding plant market. However, performance declined. Better plants aren’t always associated with bigger flowers. Petunia enthusiasm decreased. Petunias were replaced as the most common bedding flower by impatiens, which were enhanced through hybridization into super-plants with lengthy blooms and carefree growth.
The petunia industry then, according to Bodger, “fight back. The traditional multiflora petunias, which grew to a height of 3 feet but were able to bloom continuously throughout the summer without assistance, were the focus of hybridizers because they were more dependable but had fewer flowers. The aim of the industry was to produce plants that were more compact while maintaining the hardiness and prolific production of the small petunia. We watched shows like Carpet, Joy, Comanche, and Joy.
In the 1980s, hybridizers kept up their efforts. The newly created multiflora petunias had many of the same great qualities as the older varieties, but they had flowers that were considerably bigger and made the term “multiflora” appear out of place. Thus, the petunia industry, like rose farmers, established a new generic name for this kind of petunias with enormous flowers but confined growth: floribunda. This course features the well-known Madness series (Summer Madness, Sheer Madness, Coral Madness, etc.). Surprisingly, the new floribunda flowers are almost as big as those of the contemporary grandifloras, which continue to be the most popular petunia varieties and include series like Daddy, Supercascade, Flash, and Supermagic.
Where does it leave those of us who cultivate petunias? The grandfloras and multifloras, as well as the new floribundas in my garden, frequently wilt when planted in the ground.
The largest wholesale nursery for bedding plants in the nation, Color Spot, is run by Mike Vukelich Sr., the chairman of the board. He claims that the petunia’s immune system is insufficient for humid regions. Soil viruses cause petunias to die. He suggested sanitizing the dirt. I pressed him for alternative suggestions because that notion made me think of Chloroxing my flowerbeds or vaping them, which were disgusting ideas indeed. He suggested trying petunias in another area. He suggested placing them in locations with ample sunlight and sufficient ventilation in humid areas. It’s dangerous to plant them between dwellings. Also important is watering. Keep petunias as dry as possible.
The horticultural consultant Lili Singer and radio gardening expert both agreed that petunia issues are due to water. Uneven watering can cause petunias to develop root and crown rot. ” She claims that petunias shouldn’t ever be allowed to droop from either under- or overwatering, just like pansies. It’s finished when they start to wilt. She suggests creating ideal soil conditions, which include thorough mulching and organic material preparation. After watering thoroughly, let the petunias dry up almost to the point of withering. Knowing when they have dried out enough seems to be the challenging part.
Petunias prefer it hot and dry, according to Susan Brozowski, a color specialist at Sherman Gardens in Corona del Mar. They do well in the desert because of this. She plants hundreds of petunias in a coastal climate at Sherman Gardens, where a liquid fungicide is occasionally used prior to planting. However, irrigation is her main concern, which is also shared by our other authorities. She advises against scheduling irrigation. Always examine the soil; don’t apply water if it’s wet.
Petunias are frequently attacked by water and soil fungi as soon as seedlings are planted in the ground. The best moment to exercise caution is now.
Tiny holes in the blooms of petunias can indicate the presence of budworms. Buds on geranium and petunia plants are particularly alluring to little, nocturnal white moths that lay their eggs there. Tiny caterpillars are produced when these eggs hatch. The best defense is manual caterpillar collection or B.t. spraying, a benign and effective biological control.
I try to remove faded blooms from my 40 pots of petunias and feed them frequently to keep them blooming for the most of the summer. Before going dormant, my petunias in containers consistently produce color for at least 10 weeks. They are a gamble in the ground, but since there is always next year, I’ll attempt a sunnier area and use the hose sparingly.