Plant & Flower Identification

How To Differentiate Impatiens Vs Petunia? Easy Guide

It is no difficulty to see petunias and impatiens in real life, as both are very popular. Their presence is everywhere, from pots in yards, window boxes, garden borders, etc.

The flowers in bright colors make them natural decorators for houses.

Nevertheless, it is quite tricky to differentiate impatiens vs petunia, especially for new gardeners. If you feel likewise, you are in the right place.

In this article, I will reveal the differences and provide the necessary information and some pro tips for caring for these two species.

Impatiens vs Petunia: Are They Similar?

impatiens vs petunia

No. At first glance, impatiens and petunias might look quite similar regarding their blooming and leave shapes. However, they belong to different families with distinct histories.

Let’s take a further look into the similarities and differences between petunias and impatiens.


Impatiens hail from Africa, Eurasia, and North America. It explains why they would grow to the fullest if planted in moist, well-drained soil with a broad and partially shady space.

You can easily find it in areas like Madagascar, the Western Ghats in India, and tropical or subtropical mountains in Southeast Asia.

Petunias are native to South America and North America, then brought to Europe by foreign invaders.

In contrast to impatiens, they prefer a living condition of full sun, well-drained soil, and cooler temperatures yet hard freezes.

Species Varieties

Comparing petunias vs. impatiens in terms of species varieties, the former is completely overtaken by the latter.

The Petunia genus is a subfamily of a larger nightshade plant family called Solanaceae. Some of Petunia’s relatives include tomatoes, tomatillos, Chinese lantern plants, ground cherries, eggplants, etc.

There are also 20 types of flowers, like petunias within the petunia genus, for example, petunia atkinsiana. Most petunias nowadays are hybrid types with unconventional shades and patterns.

Meanwhile, Impatiens is a much larger genus with 1,000+ plant variants with various nicknames.

These varieties belong to the Balsaminaceae family and are located all over the Northern hemisphere and tropical zones.

Some common derivative flowers of impatiens are Impatiens capensis (jewelweed), impatiens walleriana (busy lizzie), Impatiens balsamina, or Impatiens glandulifera.

Petunia vs. Impatiens: Appearance

Putting two pots of impatiens and petunias together might trick many gardeners because of their similar appearances. These common ornamental plants come in an unbelievably wide range of colors.

You must examine some other external characteristics to tell apart petunia vs. impatiens.

Size1 – 3 ft. height1 – 3 ft. width6 – 12’’ height1 – 4 ft. width
StemMost are succulent stems or herbaceous annuals and perennialsSucculent stems
LeafShapeWet & ThinOval / Rhombic / Elliptic 
FlowerFunnel-shaped, blooming solitarily or in clustersMultiflorus, grandifloras, trailing, milliflora Different edge shapes: crisped, waved, curled, or doubled 
ColorPurple, Yellow, Red, White, Pink, Orange, etc.Blue, Pink, Purple, Red, White, Yellow

Natural Characteristics

Petunias thrive in full sun, so they grow better and bloom frequently during Spring, Summer, and Fall seasons. Hybrid petunias today can also be planted with hardly high demand for maintenance.

One interesting feature of this plant is that it is attractive to bees and birds without a strong smell or fragrance.

Meanwhile, impatiens get a few lovely nicknames like “touch-me-not” and “busy lizzie” because of some unique natural characteristics.

Impatiens are such delicate flowers, to your surprise. Their mature seed pods, on being touched, can “explode” and scatter inside seeds up to 20 ft. away.

Regarding the “busy lizzie” nickname, it is simply due to its mountains of blooms almost all year round.

Their “impatiens” name, derived from the Latin word “impatient”, also discloses its impressive blooming capacity.

Because of the various and bold colors, petals of some impatiens were used as nail polish or for hair dye in the past.

Impatiens Growing and Caring

flowers similar to petunias

Impatiens are quick-growing annual flowers that produce flowers constantly from Spring till Fall without deadheading.

The following are quick guides to growing and caring for these colorful flowers.


Impatiens are robust in Zone 10 & 11 but can endure colder climates.

If you live in the Northern United States or any other area with cold winters, the best time to start planting impatiens is in spring, especially in the late spring when there is no more frost.

Otherwise, the plants will likely wilt throughout their whole growing season.

Because impatiens flowers usually bloom in clusters, I recommend you plant them in a minimum space of 6-12 inches.

By doing that, you facilitate them to grow horizontally and make them excellent fillers in harmony with other taller plants in your garden.


Impatiens require a moist yet well-draining soil condition with 6-6,5 pH.

If planting impatiens in the ground with heavy clay, adding organic compost is advisable for more loosening and nutrient-rich soil.

They can also be planted in planters with suitable drainage and slight acidity. It is okay to use containers of general-purpose potting mix.

You need to provide them with more fertilizer compared to garden-grown impatiens.

Impatiens have a low tolerance for drought. You should water impatiens regularly to maintain the moist soil. Impatiens planted in containers also require more water.

However, never make soil soggy. Waterlogged soil will leave your plants more prone to diseases. For impatiens grown in window boxes, it is better using sterile or soilless mixture to promote the drainage.

Light & Temperature

Impatiens prefer semi-shady areas, so they thrive under other trees’ shade or around bushes.

Find spots in your garden where the sunlight reaches for 2 – 4 hours in the morning.

I tried and observed that impatiens with certain sun exposure had more abundant growth and more prolific flowers compared to ones completely grown in the shade.

In addition, impatiens’ growth is relatively correlated to heat. The weather with the daytime temperature of 68-85° Fahrenheit and 60-64°F at night would be the most favorable.

Because of the succulent stems, impatiens could go wilted in case of excessive and prolonged heat.

Nevertheless, don’t panic. They can quickly recover and bounce back as brand new if you water them again.


Fertilizing before planting and during the impatiens’ growing seasons is vital to provide them with enough nutrients.

Based on my experience, impatiens would develop and bloom to their fullest if you supplement a water-soluble fertilizer twice a month throughout the spring and summer.

I also get similar flower production when fertilizing them with a slow-release granular in the early spring and once again after the summer passes.

My common blending ratio is 13 : 13 : 13 or 10 : 10 : 10, but you can also refer to the instructions given on a specific product’s label.

Pets and Diseases

Among diseases to which impatiens are susceptible, downy mildew is the most common and devastating threat.

It is a fungus that causes yellow leaves, making the plants gradually die. Identification is also hard, especially during the early stage.

Their presence is only spotted after there are downy white spores on the underneath surface of leaves.

You’d better look for modern hybrid varieties which are more resistant to this fungal disease.

In case of detecting it in your present impatiens, try to cut the infected parts as soon as possible to minimize the spread though it is quite hopeless.

Besides downy mildew, impatiens have trouble with some unfriendly insects such as aphids, mealybugs, thrips, whiteflies, and spider mites.

Overwatering your impatiens can also make them more prone to undesirable viruses, fungal blights, and root knot nematodes.

How to Grow and Care For Petunias

petunia vs impatiens

Most Petunias nowadays are new-generation hybrids, which come in the diversification of colors, sizes, petal profiles, and growth habits.

They are more hardy and productive without taking too much effort to care.

When And Where To Plant Petunias

Like impatiens, petunias prefer warmer growing zones (Zone 10 – 11) to cold climates where they can only last one growing season.

They should be planted at the end of spring when the danger of spring frost is over, and the minimum soil warmth is about 60 degrees Fahrenheit.

If you intend to grow petunias from seeds, you can start seeding indoors a couple of months before the last day of the frost date.

During germination, their seeds need a bundle of light. After seeing a few leaves on young plants, you can bring them outside for planting.

These fast-growing plants will grow to their full sizes by late spring.

There are several types of petunias with different blooming styles, so the plant spacing can vary accordingly.

For example, the suitable space for Multiflora and Grandiflora petunias would be around 12 inches when planted in full sunlight and 10 inches in partial shade.

Meanwhile, you should dig holes that are at least 18 inches apart from each other if intending to plant trailing petunias.

Regarding compact milliflora petunias, they can grow in much denser populations, with only 4 – 6’’ spacing.

Soil and Water

You needn’t be picky about soil for growing petunias. Generally, they can grow in any soil mix as long as it is light and well-draining. The soil should be maintained slightly acidic by 6-6.5 pH.

Comparing petunia vs. impatiens in terms of watering, the former is more heat-tolerant than the latter.

Without rain, in-ground petunias need thorough watering only once a week. They might require slightly more in the hotter seasons. Some varieties, like trailing petunias, tend to be more thirsty also.

However, if you have flowers like petunias planted in pots or containers, you must water them on a daily basis. Petunias in hanging baskets even need to drink twice per day on hot summer days.

Remember to track the watering frequency and level and see your petunias’ responses. Overly humid soil should be completely avoided to prevent rot and fungal issues.


Unlike impatiens, petunias thrive in full sun with a daily requirement of direct sunlight for at least 6 hours. Your plants would get spindly and produce fewer flowers without sufficient light.

On summer days with extreme heat, partial shade is acceptable.


Petunias could bloom all year round if given sufficient water, light, and fertilizer. Fertilizing your petunias monthly will support their growth and blossom.

My pro tip for bigger and brighter petunias is removing their first flower flush. By doing that, your plants can save nutrients to become stronger and more profusely bloom later.

Health Problems

Like impatiens, Petunia-like flowers are susceptible to pesky pets like powdery mildew, aphids, mites, slugs, and budworms.

Powdery mildew is the most annoying and uncontrollable rival, while the others are not such serious concerns for petunias.

Besides, overwatering petunias, especially in the shade, increases the possibility of fungal diseases. Hence, avoid wetting their foliage and flowers, and moisten the soil adequately.


Impatiens Vs. Petunia – Which Is Better For Growing Indoors?

Weighing impatiens and petunias in terms of adaptability to indoor conditions, the former win. The reason is impatiens thrive in partial shade, while petunias prefer full sun.

However, growing both species indoors is still possible, even advisable during winter, as they can’t endure frost and freeze.

You can replicate the outdoor environment by using grow lights or occasionally turning the plants for sun exposure.

Are There Any Other Options For Flowers Similar To Petunias?

If you feel petunias are too common for your gardens, you can alter them with a few of the following species, which bear a close resemblance of bright and colorful appearance to their petunia cousins:

  • Angelonia
  • Bower Vine or Pandorea
  • Katie Ruellia
  • Flax Flower
  • Million Bells
  • Violas

In case you would like to build a meaningful garden besides aesthetic factor, click here for recommendations of flowers that symbolize growth.

Which Varieties Of Impatiens Should I Choose As A Bedding Plant?

There are more than 1,000 varieties of impatiens with diverse blossom colors and shapes. Regardless of the varieties you like, I strongly recommend choosing hybrids that are more resistant to downy mildew.

Here are three types that I recommend:

  • Tom Thumb Series: which produces large and double flowers with bright shades.
  • Super Elfin Series: a worthy option if you are a fan of pastel colors.
  • Swirl Series: having flowers in light pink and orange with a highlight of red-edged petals.


It isn’t easy to decide which one best suits your gardens, comparing impatiens vs petunia. Both are excellent garden fillers with a variety of colors and patterns.

The option of a specific type depends on your taste and planting conditions.

I combine several varieties from both genera as they bring incredibly charming and diverse visual effects to my garden.

Samuel Mark

Hello I am Samuel. Samuel's Garden is a garden blog where I share my experiences in garden caring and tree growth. Hope you enjoy it!

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