How To Make A Petunia Tree [In 11 Easy Steps!]

Discovering new ways to add color to your garden can be a fun experience. Have you always wanted to train your petunias to grow more as a tree than shrubs but don't know if this is possible? How can you grow a petunia tree? We'll cover everything you need to know throughout this article!

To make a petunia tree, you'll need to build a 'flower tower,' which will essentially train your plant to grow vertically rather than horizontally.

To do this:

  1. Create a cylinder using wire fencing that you can place inside your petunia's pot.
  2. Have your cylinder be as tall as your ideal petunia tree (generally 4-5 feet).
  3. Overlap the base of your wire tower to the second half, using zip ties to connect them.
  4. Trim your zip ties to about 1/4 of an inch, so they won't be noticeable.
  5. Grab a piece of landscaping fabric and wrap it around the outside of your cylinder.
  6. Overlap your fabric an inch or two so dirt doesn't fall out of the flower tower.
  7. Transfer your tower into the pot you want your petunia tree.
  8. Fill this pot 1/3 with soil and add water (this allows it to settle).
  9. Repeat the above step and fill the rest of your tower once that is done.
  10. Cut horizontal strips on every other panel throughout your tower.
  11. Plant your petunia, give it some water, and you're all set!

As we start, we will cover all things petunias and discuss how to turn yours into a tree. Whether you've never thought of doing this or need some extra guidance, we're here to assist. With that said, let's dive right into this topic below!

How To Make A Petunia Tree [In 11 Easy Steps!]

Is There Such A Thing As A Petunia Tree?

Sweet petunias flowers in full bloom growing in garden captivating color.

Although there isn't technically a petunia variety that will grow into a tree, there are ways to train a regular shrub to grow vertically.

Like most flowers, you can't expect a petunia to form a 5-6 foot tree without assistance, so you'll need to get your plant moving in the right direction.

As we said, you can do this by creating a flower tower. Some gardeners will also use tree stands or trellis' to train their petunias to grow vertically, so there are options here.

Even though a flower tower or tree stand seems intimidating, your flowers will extend upwards or downwards with time, creating a "tree-like" look.

Moreover, you also want to ensure you're in the correct USDA growing zone for your petunias to be perennial because they act as annuals in most places.

According to The Old Farmer's Almanac, you can grow petunias as tender perennials in zones 9-11.

How Can I Make A Petunia Tree?

Blooming Petunia tree, How To Make A Petunia Tree [In 11 Easy Steps!]

Now that you know the basics, it's time to create your tree. As we mentioned above, you'll need to grab wiring and make a cylinder with it.

Ideally, this structure will be between four and five feet tall, although you may want to start a bit shorter. Remember, you'll need to train the petunias you plant in/around this tower to fill it out, which can take years to accomplish.

When you have your cylinder put together, we recommend filling it in thirds, adding water, and repeating this process until you're a few inches from the top of your petunia tree.

Using a landscaping fabric will suffice, although you need to cut tiny holes on every other panel so that oxygen and water can cycle through your petunia tree's soil.

According to expert DIY'ers, you can use zip ties to secure your fabric and wire to each other, which we also suggest doing.

You'll need to trim the ends of the zip ties to make them less noticeable, so add a pair of gardening shears to your shopping list.

Here's a helpful YouTube video showing you step-by-step how to create your petunia tower:

Vensovo Store Chicken Wire

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ECOgardener Premium Landscape Fabric

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How Fast Do Petunias Grow?

You can generally expect your petunias to germinate and grow pretty quickly. Suppose you're growing your tree from seed; your seedlings will need about 1-2 weeks to germinate and begin sprouting from the soil.

Many experts claim that you should start petunia seeds inside under a concentrated heat lamp, although this isn't always necessary if your garden gets plenty of sun.

Once your seeds begin to sprout, you can expect them to mature within 12 weeks. Of course, this will be different for those growing a petunia tree, as you'll need to carefully train your plants to fill out the tower you've created for them.

Furthermore, we recommend planting many petunias per tower, as this increases the chances of yours filling out. The last thing you want is 1-2 petunias trying to take on such a large amount of territory.

You should also consider the climate/USDA zone your tree is in. As we said, zones 9-11 are the only known regions where you can grow petunias as perennials, so anywhere else, you're likely to have them be annual.

Typically, the warmer your garden is throughout the year, the better chance of a petunia tree flourishing.

How Fast Do Petunias Spread?

Depending on the variety/conditions, it's possible to see a petunia spread rather fast. As long as your petunia is a "ground cover" or "spreading" type, it's likely to see it extend dramatically within the first few months.

In terms of size, some petunias spread between 18 inches and four feet, which is perfect for creating a tree. Considering your wire structure will be a few feet tall, having a fast-spreading petunia variety is essential for its success.

It's also worth noting how many petunia varieties will only grow about six inches tall, so training them to extend downwards from the top of your tower could be a better idea.

Regarding a great petunia variety for doing this, we recommend 'Wave' petunias, as they cover a lot of territory within a short timeframe.

You can also find these in various colors, like purple, white, blue, etc., so there's something for everybody.

Burpee Purple Wave Petunia Seeds

This packet of purple wave petunia includes 15 pelleted seeds, will spread roughly 48 inches, prefer warmer conditions, includes product care instructions, and has an expected spring/fall blooming period.

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How Many Petunias Can You Plant Together?


You can usually plant up to three petunias per 12-inch pot, so that's a good reference to follow. Like any species, you need to give your petunias enough room to develop roots and absorb nutrients, water, and oxygen from the soil.

If you plant petunias too close to each other, your plants' roots will likely tangle, potentially killing them both. Therefore, it's imperative to space your flowers out so they can mature and spread cohesively.

The same applies to a petunia tree. Even though your flowers need to fill out the structure, that doesn't mean you should have them so close that they are on top of one another.

Instead, try to give them 6-12 inches of space, so they can grow without becoming enemies. Regardless of the plant you try and grow, if they are too close, one will likely overpower the other.

This, unfortunately, is how the natural world works, often with stronger plants taking over and killing weaker ones that try to attach to their roots.

As we said, petunia spreads relatively fast, so when you think about it, there's not much need to plant so many per plot of land.

Do Petunias Multiply?

Blooming petunias

Yes! It is possible to see petunias multiply, eventually taking over an entire area of your garden. Generally, this will occur if extra seeds make their way to other sections of your yard, although petunias tend to cross breed on their own.

On the other hand, you might mistake your petunia for multiplying, but it's instead spreading.

Remember, this flower species can get as wide as four feet in all directions, which is impressive for any structure or landscaping.

As long as you water and occasionally fertilize your petunias, it's probable for them to multiply, expand, and hopefully fill out the tree tower you're training them to grow throughout.

Are Petunias Easy To Grow?

Beautiful petunia flowers

Yes! Petunias are a fan favorite among gardeners due to their easy upkeep and ability to flourish. There are an estimated 100+ petunia varieties known as of now, so you're bound to see these wherever you go.

Generally, as long as you keep your petunias somewhere with good draining soil and enough sunlight, they'll spread quickly.

An interesting fact about these flowers is that they are particularly heat and drought-tolerant, which isn't usually the case for flowering plants.

You can also expect 'wave' petunia varieties to crawl/spread across larger surfaces, hence why we recommend using them for your tree.

To Finish Everything Up

Whether you have various petunias growing throughout your garden or want to plant some, it's always good to know what they're capable of.

From what we found, you can make a petunia tree if you create a cylinder-shaped cage for your petunias to attach to. You also need to wrap your structure in landscape fabric, which will hold the soil for your plants.

Furthermore, it's best to find ground covering or 'wave' petunia varieties, as they will grow the fastest and cover the most territory. Good luck gardening!

Made it to the end? Check out these other helpful related garden posts below:

Do Deer Eat Petunias? [And How To Stop Them From Doing That]

Where To Buy Petunia Seeds (Top 30 Online Stores)

Petunia Seedlings Not Growing - What To Do?

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