How to Keep Wave Petunias Blooming

Blue wave petunias blooming

One of the draws to planting wave petunias is their beautiful blooms — but what if they stop blooming?

There are multiple reasons wave petunias may stop producing blooms in your garden, pot, or landscape border. Many of these reasons are tied to the primary needs of a Wave petunia plant — in other words, when properly caring for your wave petunias the plant will bloom more.

Starting, it’ll be helpful to review the basic requirements of wave petunias.

About wave petunias

Wave petunias grow best with at least 6 hours of sunlight, warmer temperatures, well-drained soil, adequate fertilizer, and occasional trimming.

In Pennsylvania, growers begin growing wave petunias around late April or early May for a long and rewarding growing season. Wave petunias can handle some chilly nights in early spring, but you’ll want to be careful when planting your annuals outside in the spring.

Now, let’s discuss some common reasons that your wave petunias may have stopped blooming.

6 tips for keeping your wave petunias blooming

It comes down to your plant health. If a wave petunia is taken care of correctly, it will be able to grow to its full potential. This means plenty of blooms and vigorous blooms.

The reverse is also true. If you find that your wave petunia plant did not have the best start or didn’t receive the care it needed early on, it may need a little extra care to get it back on track.

Even so, focusing on some of the below areas your wave petunias may be able to recover.

1. Make sure they are getting plenty of sunlight

Wave petunias, and petunias a whole category of plants, love the sun. They’ll want at least 6 hours of sunlight, doing well well up to a full day of sun.

If you planted you wave petunias in a shady location and the plants just aren’t blooming like you’d like them to it’s likely due to lack of sun. Other plants, like begonias, offer the benefit of adding color to a shady spot on your property, but not wave petunias.

A lot of times wave petunias are a plant that growers will plant in a hanging basket. It’s one of the popular types of plants growers use for hanging plant arrangements. If you are growing them in a hanging basket or pot, the solution is to simply move the container to a spot where it’ll get more sun.

Purple wave petunias in a hanging basket

2. Keep them watered — but don’t overwater them

On the other end of the spectrum, if your wave petunias are getting a lot of sun and not enough water you may see the plants not bloom as much.

Water and sun are some of the basic needs of a plant, so make sure that the plant is properly watered.

A good way to check is to check the top inch of soil for moistness. If the soil at the surface is at least a little damp it’s likely OK.

If growing the wave petunias in a hanging basket, you can lift it from underneath to get a feel for its need for water. It should feel noticeably heavy if its well-watered, and noticeably light if it needs water.

Wave petunias can be prone to root rot and other diseases if overwatered, so make sure that you are watering these plants enough, but not too much. This way, your wave petunias will rebound with plenty of blooms.

3. Fertilize the plants when needed

While watering, make sure to add a water-soluble fertilizer when necessary. Like other plants, wave petunias need their nutrients, so it’s important to keep them well-fertilized.

Use any fertilizers as instructed and keep the season in mind. Often, over the summer where you may be watering every day, you may need to water 1-2 times a week, but in the spring and fall, this interval will likely change.

Wave petunias aren’t as forgiving as Supertunias with lack of fertilizer — if you see their vines begin to yellow up you know they could use some more nutrients.

4. Give them space

Wave petunias are spreaders, so make you provide them that space! Their vines can grow as long as 4 feet long, so it’s recommended that you plant them at least a foot apart.

Wave petunias that have limited root space, like when planted in a flower pot or hanging basket, may not be able to grow to their full potential, meaning not producing enough flowers.

5. Trim the plant to promote growth

Finally, trimming back your wave petunias is a great way to promote the growth of more blooms. It may seem counter-intuitive to cut back your plant when you want it to grow more, but this is often what is needed when dealing with a straggly plant.

6. Treat it for budworms

Three colors of wave petunias

It’s possible that you have been doing everything perfectly and the wave petunias are still blooming. The culprit may be the budworm.

Budworms are insect pests that plague many types of garden plants, especially petunias.

You’ll likely notice holes in you wave petunia blooms if your plant is being impacted by budworms. If Pennsylvania, if noticed that these tend to be a problem in late summer.

There are many ways to treat budworm — we have found Thurocide to be effective at killing budworms and bringing back those blooms.


If you wave petunia has stopped blooming the reason is likely due to not giving the plant the care that it grows the best in. If you are providing the plant with the water, sun, and fertilizer it needs, then it might be due to a disease or insect infestation.

Many of these tips can be used for other petunias, such as Supertunias.