If you want your trailing petunias to create long, dense trails out of baskets and containers, they need at least 6 hours each day of direct sunlight.
Of course, you can plant them where there is less direct sunshine, but their growth will be less rapid.
Drainage is also crucial, so lift any ground-based pots or containers with pot feet to prevent root rot.
How to Deadhead and Prune Trailing Petunias
Deadheading a plant does two things:
- to organize the plant and make it look better.
- to stop plants that set seeds from “going to seed. An annual plant frequently stops growing after it begins to produce seeds because it has fulfilled its reproductive function. By deadheading and preventing the plant from developing seeds, this can be avoided and growth can be prolonged.
A short Google search turns up dozens of authors who assert that if you want lengthy, dense trails, you should deadhead trailing petunias as frequently as you can.
There are various petunia types, such Wave and Surfinia, which grow well with relatively minimal deadheading and are ideal for the time-constrained gardener.
Regular deadheading (at least once a week, but ideally twice a week) is advised for the majority of other varieties of petunias.
Make sure to remove the seed pod along with the blossom after deadheading.
Pruning
One of the most crucial chores is pruning, but it’s sometimes ignored or done improperly.
When a stem is cut, side shoots emerge and eventually grow into new stems.
The few stems you have will grow long and lanky with few side shoots and blooms if you don’t prune enough or forcefully enough.
We advise deadheading petunias once a week and trimming back any long, lanky stems to promote side-shoots that will trail. Start by trimming any stems that are frail or have few blooms or leaves.
When pruning, try to keep a uniform shape, but if the plant is a little lanky and sparse, don’t be afraid to remove half or more of the growth.
You can simply go ahead and forcefully trim back your plant to just below the rim of the basket or container if you believe it is already too far gone and is severely neglected, lanky, and lacking in blossoms. Always fertilize regularly after any vigorous trimming to promote growth.
How to Avoid “Flat Topping
Not only will the ideal petunia hanging basket or container have long trails, but it will also have a well-rounded top part with blooms and lots of leaves.
The top of the basket will appear flat and sparse if you let all of the stems in the center of the basket grow long and overflow the edge.
Simple pruning of the lanky stems to promote bushy growth near the top of the basket or container will easily stop this from happening.
Just go ahead and aggressively trim away any neglected trailing petunias until there are about 12 inches of the plant protruding over the edge of the basket. The plant will grow quickly, and much of it will be in the top part.
How Often Should Trailing Petunias be Watered?
Here is how often we water the containers and baskets we use for petunias:
- Summer days that are overcast, cool, and gloomy occur every two to four days.
- Every day or every other day in the heat, typical daywater.
- Very hot summer days, especially in the morning and evening.
Petunias need a lot of water, yet the roots prefer a soil that is damp but never soggy. Additionally, the baskets or containers should have a bottom that freely drains water.
If you water the basket and it starts to drain out the bottom right away, it’s likely that the soil is too dry and has contracted, and the water is just fleeing through the cracks. To fix this, water the plant, let it sit for 15 minutes to allow the soil to swell, and then water it once more. Moving forward, make an effort to stop the soil from drying out to the point where it shrinks.
Can petunias be overwatered? Yes, root rot is a possibility, but it typically only arises when a container or basket lacks drainage holes or when the potting soil is so dense that the water cannot escape. View the potting soil and baskets we recommend at the top of this page.
Even though it has been raining, should you water the petunias? It’s unlikely that a brief summer shower would be sufficient because we often water our petunias heavily. So we continue to water them even after it has rained. Although many are positioned beneath the roof overhang, which shields them from the majority of the rain, baskets and containers are frequently quite small and only catch a small amount of rain.
You must be careful not to drown the plant by flooding the roots if your basket or container has just one or two drainage holes.
Fertiliser and Feed
Every gardener will have a different answer when you ask them how frequently they fertilize their petunias. Nutrients that are flushed out of hanging baskets by watering need to be renewed, however there is no defined schedule.
Unfortunately, even plants in hanging baskets might receive too much fertilizer. Yellow leaves and stunted growth can result from having too much zinc, manganese, copper, or phosphorous, which can prevent iron from being absorbed.
Petunias grown in baskets should be fertilized every week. Therefore, every seventh watering will be required in the summer when you water once daily.
Since you won’t be watering as frequently and the nutrients won’t be washed out of the basket as frequently during cooler times, you can cut the frequency to around once every ten days.
Of course, fertilizing every two weeks will still yield fantastic results, but we believe applying more regularly will result in better development.
You won’t need to fertilize petunias in flowerbeds or the ground as frequently. Petunias planted in large containers don’t require as regular fertilization either.
Keep in mind that summertime drying out can cause baskets to require more watering. More fertilizer is needed to replenish lost nutrients the more water is used.
Watch out for symptoms of overfertilization like yellow petunia leaves. If that occurs, turn it down and give the petunias some iron that has been sequestered.
Best Fertiliser For Petunias
Starting with an excellent all-arounder like Miracle-Gro soluble universal fertilizer, which has a high concentration of nitrogen and is ideal for promoting long trails, is what we advise.
If you see that the petunias are a little lanky and are producing few or small blooms as the season progresses, you can replace the occasional feed with fertilizer that has a higher ratio of phosphorus.
In order to preserve the petunias’ leaves lush green, we also advise giving them a monthly dose of sequestered iron.
With the use of this product, we were able to restore the petunia foliage to a vibrant green color.
How are trailing petunias maintained?
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.
Do you remove trailing petunias’ pincers?
Petunias’ tips can be pinched out to encourage new growth by releasing growth hormones. Pinch all petunias when you plant them in the garden since doing so aids new transplants in establishing themselves more quickly. Deadheading on time promotes a large number of flowers. The plant will substantially reduce the amount of fresh blooms it produces if you let the blossoms go to seed since it will believe its life cycle is over. Garden petunias are hybrids, not true from seeds, therefore there is no point in trying to let them reseed themselves.
Can you plant trailing petunias in the ground?
Petunias can be grown from seed, purchased as little plug plants to grow on, or purchased as plants that are ready for the garden. Because petunias are delicate and cannot withstand any frost, you must wait until late spring or early summer to plant them outside.
A good, rich soil is necessary for petunias to grow well. Before planting, prepare the soil in borders by incorporating a lot of well-rotted compost or soil conditioner. Petunias grow best in multipurpose, peat-free potting compost for pots and containers. Choose a compost that has water-holding granules for raised containers like hanging baskets and window boxes that are exposed to drying sun and wind.
Petunia spacing is greatly influenced by their development pattern, final size, and the environment in which they are produced. Plants can be crowded closely together in pots and other containers to create a stunning display quickly. The smallest compact and upright kinds can be planted as close together as 15-20 cm; bushy petunias with a loose, mounding habit require a wider spacing of about 30 cm; and trailing varieties require a spacing of about 40 cm.
Petunias should be gradually acclimated to the outside for a week or two before being planted outside. When purchasing garden-ready plants, make sure they haven’t been kept in a covered area or in the event that they have, they will need to be hardened off before planting.
Where to grow petunias
Petunias require a lot of sunlight, rich soil, and protection from wind. Petunias will also thrive if given some shade in regions of the country with hot summers or milder climates.
Because of their extreme adaptability, petunias can grow in practically any kind of pot or container, regardless of size or shape.
Petunias that trail off the sides of pots or window boxes make excellent plants for hanging baskets, raised pots, or window boxes. They can be planted to tumble down slopes, banks, and from raised beds, and they create a distinctive and vibrant ground cover in borders.
In a colorful bedding arrangement, as a splash of bright color amid the perennial plants in a border, or as part of bushy, upright arrangements in pots or planted in the ground, petunias make excellent displays.
Petunias grown in pots and containers require regular watering, which is crucial. Avoid letting the compost dry out, but also be careful not to overwater it because this can result in spindly growth. During dry seasons, petunias planted in the ground also require watering.
To prevent sunburn on the tender leaves and huge flower petals, direct the flow of water onto the earth rather than showering the plant. In order to avoid burning, try to water in the early morning or late at night when it’s hot outside.
Feed plants with a potash-rich liquid fertilizer every 10 to 14 days in the summer and early fall (such as tomato fertilizer). Switching to a high-nitrogen fertilizer can accelerate growth for the final few weeks before the frosts if plants start to look drained in the fall.
Petunias appear better and produce more flowers when fading and dead flower heads are removed. Later in the season, trailing kinds that start to look straggly can be softly clipped. Feeding simultaneously will encourage new growth.
How to propagate petunias
Although they are not the easiest of plants to propagate, petunias can be produced from seed. When the temperature is 21C in late January, seed should be sowed. Petunia seeds need light to germinate, so don’t cover them. Instead, sow them on the surface of moist compost and cover them with polythene or place them in a propagator to keep them from drying out. Seedlings require a warm, well-lit, shaded habitat that is between 13 and 15 degrees Celsius.
A excellent middle ground between starting from seed and purchasing more expensive garden-ready plants is to purchase petunia plug plants. Early to mid-spring, mail-order plug plants are available. Plant them out only after hardening off and when all threat of frost has passed in individual 9cm pots and growing on a well-lit windowsill or in a heated greenhouse.
If pruned and transferred into a warm setting, some petunias, primarily trailing kinds, can be retained during the winter. If you don’t have much room, root cuttings in the late summer, pot them up separately, and store them indoors on a ledge for the winter.
Growing petunias: problem solving
Given the proper growing conditions and maintenance, petunias are often trouble-free. Young leaves and stems may develop aphid infestations; you may prevent this by checking your plants frequently and manually eradicating any tiny infestations. To control aphids, there are a variety of ready-to-use sprays available.
Snails and slugs can be an issue, especially for petunias that are rooted in the ground. Before putting petunias outside, grow them to a good size because larger plants are far more equipped to survive attack. Use an eco-friendly bait or surround plants with absorbent granules or barriers.