ADVICE Below On How Often To Water Petunias

Are Petunias Perennials?

Even though most types of petunias are grown as annuals from seed every year, petunias are perennials. But are you aware of how often to water petunias? The trailing variants, such as Surfinias, are perennials propagated through cuttings or by starting completely new plants. 

Petunias are grown as annuals the vast majority of the time. You must activate them in regions with moderate winters and temperate summers not exceeding 90 degrees Fahrenheit (32.2 degrees Celsius).

Red petunia

The Different Types of Petunias


Love large, colorful blossoms that make a splash? The size of Grandifloras more than makes up for the fact that they don’t normally produce as many flowers as other varieties. Between 3 and 5 inches (7.6 and 12.7 inches) across, they are large and flashy. 

There are different cascading Grandiflora kinds, such as those from the Cascade or Super Cascade series, the Diamond series, and the Explorer series, which also functions as a ground cover. Grandifloras and other flowering plants with long, flexible stems that trail is sometimes known as pendula-type petunias. 

There are also some dwarf Grandiflora cultivars, such as those in the Limbo series, that only reach heights of 4 to 8 inches (10.16 to 20.32 centimeters) without turning lanky. If you want something more compact that produces more blooms than your standard Grandiflora, look at the Flash Sweetunia series.

Additionally, you must deadhead Grandifloras regularly to keep their attractiveness. When buying seeds or seedlings, remember that you often find cultivars in various hues within a specified series and mixed possibilities. 


On more compact plants, multifloras produce a lot of blooms, but they’re smaller than Grandifloras and only around two inches across. These typically spread 10 to 15 inches (25.4 to 38.1 centimeters) and grow 10 to 12 inches (25.4 to 30.48 centimeters). If they begin to get lanky, pruning may be necessary. 

The Mambo plant series is a wonderful choice if you’re looking for a dwarf selection. The fact that these flowers frequently clean themselves is a beautiful benefit of selecting this kind. 

If this is the case for the type you choose, the spent blooms will fall off naturally without the need for deadheading, making them the best option for extensive plantings. 


Like those in the Wave series, some floribunda plants are spreading kinds and sometimes paired with multiflora plants. These plants, hybrids of the Grandiflora and multiflora types, combine the best traits of each by having many blooms, a tolerance for wet weather, and increased disease resistance.

Although some plants are more compact, they typically stand 8 to 15 inches (20.32 to 38.1 centimeters) tall and spread across 10 to 12 inches (25.4 to 30.48 centimeters). These varieties frequently need some deadheading or pruning because they are not self-cleaning.


These little petunias, one of the most recent imports, with single, smaller flowers that typically measure just one to one and a half inches in diameter. But what you gain in quantity, you lose in size. The majority of the season will have blossoms on multiflora plants.

They are especially suitable for gardens with limited space, and most milliflora varieties are self-cleaning, so deadheading is unnecessary. The dwarf plants have a mounding habit and are more compact than other kinds. They often only reach a height and width of eight inches. 

Compared to spreading ground cover kinds, which requires a distance of three feet, millifloras only need spacing of four to six inches apart.

Trailing or Ground Cover

Typically only growing to 4 to 6 inches (10.16 to 15.24 centimeters), this set of series and cultivars develop quickly and disperse energetically, covering 10 square feet (0.93 square meters) of garden beds or borders per plant in a single season. 

They are very heat and drought resilient, with certain types known as spreading or hedgiflora-type plants, and they typically don’t need deadheading to look attractive.

For instance, tide waves fall under the Hedgiflora type because of their capacity to create a dense and rich ground cover. 

Although they technically belong in other categories, as noted above, several different wave series plants are frequently members of this category. These plants stand out when planted in hanging baskets because of their creeping growth habit, which causes the vines to trail over the sides rather than along the ground. 

Additionally, remember that trailing petunias can serve as the “filler” and the “spiller” when building your own blooming pots for the patio or balcony garden in the summer.

Purple petunia

How Long Do They Last?

How long do petunias last? In addition to single or double blooms, smooth or ruffled petals, striped, veined, or plain colors, mounding or cascade growth patterns, and even smell, most petunias sell as hybrids. Petunias develop quickly; they will be fully grown by late spring. 

The estimated final spring frost date for your location will determine when to plant petunias; the plants need no exposure to any frost. Petunias can bloom all summer long if you provide them with ample sunlight, water, and fertilizer, deadhead the spent blooms, and cut back scraggly foliage. 

Petunias are annual plants that only thrive for one growing season in colder climates. Petunias will reappear each year in their warmer growing regions, but they only live for around three years. They will, however, self-seed to continue growing.

How Often to Water Petunias?

A newly planted Petunia will adapt and settle in more easily with routine watering. In the first one to two weeks after planting, water new plants every day as soon as they are in the ground or a planter. 

Throughout these first few weeks, make an effort to maintain consistently moist soil. Once the Petunia has established itself, you can postpone watering until the top inch or two of the soil has dried off. 

It may be necessary to water every few days in dry locations or during a drought, so keep an eye on the soil and the weather and water as necessary. Petunias in hanging baskets or pots will require considerably more frequent watering.

Signs and Damage Caused Due to Overwatering

Root Rot

The result of overwatering your petunias is root rot. Petunia roots will rot and die if you keep watering them more frequently than is advisable. Looking at the plant’s roots, you can see that root rot has taken hold. They’ll appear fragile and like they’re falling apart. It’s rare to salvage a plant once root rot has set in.

Petunias Look Wilted Despite Soil Being Wet

Wilting is the most typical symptom of overwatering in petunias. Usually, you’d anticipate a plant to begin wilting when you haven’t been providing it with enough water, but when your plant is wilting even though the soil is moist, it is clear that you have been overwatering it. 

Brown Leaves

Another indication that your petunias aren’t thriving well is the presence of brown foliage. Overwatering your plants might eventually result in browning of the leaves, typically accompanied by wilting. 

Before the petunias begin to fade significantly, you might notice that some leaves start to turn brown. 

How Much Water Do Petunias Need?

The flowers benefit from regular watering to remain in bloom. Because petunias prefer direct sunlight, be aware that hot weather can cause container plants to dry out more quickly. The plants require two daily watering during these times. 

When the top 5 to 6 inches (12 to 15 cm) of bedding plants start to dry out, they need water. Plants that are in beds require deep watering once a week. Deep watering encourages the growth of strong, long roots in plants.

How to Water Petunias

Because petunias thrive best in bright sunshine, keep in mind that their soil may dry out more rapidly in containers when the temperature is high. When conditions are like this, the plants need watering twice daily. When the top 5 to 6 inches (12 to 15 cm) of the soil begins to dry, bedded plants need watering. You will require heavy weekly watering of the plants in their beds.

How Do I Know If I Need to Water Them?

How do you determine whether petunias need water? Feeling the soil is the best way to know when to water Petunias. The plant requires water if the top few inches of the soil are dry. The plant is too dry if its leaves are drooping or turning yellow and the earth has cracks. 

If the plant appears dehydrated, give it some water straight away. If it dries out too much, it may not recover and become lethal. Hold off on watering if the soil is wet because overwatering is just as detrimental for petunias.

What is the Best Time to Water Petunias?

The ideal time to water petunias is whenever the soil feels dry. Early morning watering of the plants can help them survive through the hottest and sunniest time of the day, like early afternoon. Petunias become dormant in the winter and require less water. Do not water until the top few inches of soil are completely dry.

Other Petunia Watering Tips

Here are the steps on how to water your petunias carefully and in the right way:

  1. When the top 1 to 2 inches (2.54 to 3.08 centimeters) of soil are dry, feel the soil with your hands to determine how wet and moist it is.
  2. Saturate the soil – Water the area around the plant well to encourage root development. A large root system will help the plant survive and promote more blooms.
  3. Be gentle. Petunias can tolerate little moisture, but an excessive amount could damage or flatten the flowers. Instead, attempt to hydrate the area around the plant.
  4. Keep the soil from drying out entirely. Check on the plant every few days to ensure it doesn’t get too dry.
Watering petunias

Final Words

What is a petunia? Petunias are cherry annuals that reliably bloom from the beginning of summer until the first frost in the fall. What do petunias look like? These bright garden classics come in a dizzying array of colors, dimensions, and shapes. 

This article tells you everything you need to know about a few of the several petunia varieties, including purple petunias. 

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