Are Petunias Perennial or Annual?

Are Petunias Perennial or Annual?- Petunias are technically Perennial flowering plants. Although it is pretty hard to keep them alive during the frost in winter or hot summer days. These beautiful flowering herbs are easy to grow and maintain. They require specific conditions to grow like proper soil, ambient temperature, and favorable climate.  It is difficult to keep all of these factors in control throughout the year. All popular varieties of petunia prefer warm winter and cool summer days. It can neither survive frost nor too much heat. That’s why petunia is grown as Annual Plants.

We can grow petunias in USDA hardiness zone 4 through 9. It can behave as perennial in zone 7b through 10 whereas they are annuals elsewhere.  Instead of working whether petunia is perennial or annual. You should think of which way is better to grow them. And Always buy the Best quality Petunia seeds to grow them.

Petunia always blooms in new branches. Therefore the plant needs to keep branching consistently. There is a slight problem with this approach. Every perennial plant loses its strength with time. For petunias, it means poor quality bloom. Although the petunia plant is consistent with bloom quality in its first year. It will not perform the same next year even if you manage to save them.

That’s why it is better to plant fresh petunias every year and grow them as Annuals.

Are Petunias Perennial or Annual?
Are Petunias Perennial or Annual?

Check out my previous post: How to Grow Sampaguita Flowers- Jasminum Sambac

Can Petunias Come Back every year?

Yes, Petunias can come back every year. Some of them can survive and keep blooming next year. They are perennial and can continue blooming for a couple of years. If you live in a place where summer is not too hot and winter is not so cold then Petunias can survive a couple of years.

Others may die and regrow from previous season petunia seeds. Each petunia plant can produce 100 even thousands of seeds in the flowering season. Almost 40-50% of these seeds may germinate and grow into new plants. Once the flower matures it forms a small seed pod full of tiny petunia seeds. The seed pod dries in 5 to 8 days and scatters the seeds in the soil.

In favorable conditions, these seeds may germinate and grow into new petunia plants.

Usually, new seedlings grow to replace old dying petunias. These new petunias always have fresh blooms. In both ways, petunias can come back every year.

What is The Lifespan of a Petunia?

Petunias are perennial flowering plants. Their lifespan depends greatly on their variety, temperature, soil condition, as well as maintenance. These plants are technically perennial although keeping them alive during winter or hot summer days is quite difficult.

Every petunia variety prefers cool summer conditions and frost-less winters. This is not possible everywhere. Therefore the real and realistic lifespan of a Petunia plant is 6 months. They can survive well from early spring till late summer.

In the frost-free zone, the seasonality changes from early fall till early summer. Here the winters are warm and summer days are too hot for petunias to survive.

Do petunias need to be planted every year?

Petunias are technically perennial so there is no need to replant them every year. Although the change of temperature is not favorable for these plants. They can’t survive too much heat or frost. So summer and winter both season is not soo good for petunia plant care.

Usually, the petunias plants end it blooming in late spring and the plant dies during peak summer days. Those who survive the summer days will definitely die in cold winter. That’s why we prefer planting new petunia seedlings every year.

Although Petunias are self-seeding plants. They will develop a lot of seeds and scatter them in the soil. These seeds may germinate and replace the dead plant by early spring. Therefore you may not need to plant petunias every year especially if the seeds are well preserved in the soil.

How to Grow Petunia as a Perennial Plant?

Growing petunia is easy although growing them as perennial is quite difficult. These beautiful flowering plants are quite delicate with temperature and maintenance. They prefer a consistent temperature of 20 degrees celsius or 65 Fahrenheit. Minimum 4-6 hours of direct sunlight with 70% or more humidity is essential for petunias.

These conditions are natural during spring through early summer and also during fall in some areas. Although maintaining a similar environment for years is a little tricky job. It is a difficult task but certainly possible, especially inside a greenhouse.

Greenhouse can maintain a small ecosystem on their own. It is easy to regulate temperature and moisture inside a greenhouse. Therefore growing petunias in a greenhouse is the best way to keep them perennial.

You can only try to save these plants from heat and frost outside the greenhouse. It is often not so easy to do. That’s why we are here to discuss a few possible options to keep your petunias alive till next spring.

Read this: Grow Crops for The Local Market in your Garden

How to Prevent Petunias from Dying in Summer or Winter?

  • The summer season is the first problem especially if the temperature exceeds 35 degrees celsius. Temperature and sunlight at this range can burn the plants within days. Therefore you have to provide proper shade to extend plant life. Green nets with 50-60% density are ideal for petunias on hot summer days.
  • During Monsoon or rainy days, root rot and pest problem are troublesome. It is very difficult to prevent all of these pests and bugs to attack your delicate petunias. You have to prepare for this situation before it happens. You should mark the natural rain cycle in your zone. Once done get started with early soil treatment for proper drainage and funds control. Treat the plants with fungicide and pesticide weeks before scheduled rain starts.  These are the only ways to keep your petunias safe during monsoon season.
  • The next and final problem is the heavy frost. If you like in cold zones with mild to heavy frost in winter then petunias will not survive outside. You have to move them inside or mulch them heavily to protect their seeds outside. Container plants must be kept inside greenhouses or in rooms with normal temperature and humidity. You can feed these plants with light nitrogen-based fertilizer and compost to keep their roots warm.
  • Modern hybrid petunias are specially derived for single-season growth. Therefore protecting them for next season flowering is not feasible. Sometimes you may save them with the best efforts yet getting good quality blooms in next spring is not very easy in these plants. It is better and easy to replace them with new seedlings and get fresh bloom in the season.


Hi, My name is Sukant. I am an I.T professional. Gardening for me is not just a hobby, it's a way of living life with nature. My Ancestors were Commercial farmers: So I personally feel attached to the green. I am not an expert, I'm here only to share my gardening experiences. It's always Refreshing.

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