Petunias are beautiful, vibrant flowers. When you have a dependable petunia, it can last from spring all the way through the fall and will provide you with a lush color in your garden beds and along any borders of your property.
Petunias are grown typically as annuals, but they can grow as short-lived perennials. This depends on the hardiness levels of the area where you live, so be aware of that if you plan to let them grow a bit longer.
There are times, however, where your beautiful petunias can begin to look a little leggy and begin to sag. Not only that, they will begin flowering very poorly right around the midsummer mark.
Thankfully, there are ways to bring your sagging petunias back from the proverbial dead, making them look fresh and strong once again.
A Common Cause for Sagging Petunias
One of the most common issues when it comes to sagging, leggy petunias is that there is not enough water getting to the roots. Feel the soil; if it feels dried out (almost like a brick in texture), that is a good indication that water supply is an issue.
A serious lack of moisture can also result in the roots becoming bound. This can happen quite easily, but can also be remedied quite easily as well.
If you want to avoid your petunias sagging and becoming bedraggled, make certain that there is plenty of moisture and allow the pot to be loose and free draining.
By keeping the soil moist and preventing it from becoming dried out and root bound, you can keep your petunias from sagging. But if they have already become dried out and dangling, you can remedy the situation and get your petunias looking good again.
Pruning and Basic Maintenance
Generally speaking, you can save your sagging petunias from an untimely end with a little bit of basic maintenance and pruning. You start by cutting back the overgrown, lanky plants to around half of their height.
To do this, you need clean, sharp shears. When petunias begin to develop leggy, weak growth – generally halfway through the summer – you can shear them back. This forces a new flush of healthier and more compact growth.
From there, you need to monitor your soil moisture, especially when the temperatures begin to rise. Be certain to water your petunias when the top inch or so of soil begins to dry out. You will want to keep your garden provided with an inch or so of water on a weekly basis or enough to keep the top six inches of your soil moist.
If you have petunias in potted plants, you will need to water them daily or right when the top inch of your soil begins to feel dry. Let the excess moisture in the pot drain out of the bottom freely so that the excess fertilizer salts can properly drain out.
After the soil has been properly drained of fertilizer salts and excess moisture, you need to sprinkle in about a quarter pound of 5-10-5 fertilizer. Do this over every 50 square feet of your petunia bed right around midseason, since this is the time where petunias can struggle the most.
Do this after you have cut back your petunias and apply the fertilizer six inches or so away from the base of your petunias. Make certain to water your soil thoroughly so that the fertilizer dissolves evenly into the soil itself.
Spreading the Mulch and Finishing the Process
When you have trimmed down your petunias and begun to spread your fertilizer into your soil, now comes the time to mulch. Take mulch and spread it around your garden beds until it is about two inches in thickness or so.
Mulch is a great way to keep your soil cool, providing some insulation against the strong midday heat. Not only that, the mulch can help to conserve soil moisture. This helps to prevent heat stress, which can dry out your soil and result in sagging petunias.
If you are growing your petunias in potted plants, move those pots off to an area that has some shade in the afternoon. This will also keep them protected from the heat and prevent heat stress from taking place.
When you have spread your mulch around your garden, it is time to pinch off the dead petunia blooms. Do this as soon as they wilt because this encourages further flowering and can actually prevent weak growth.
You will want to pinch back the long stems to within a quarter inch of a leaf. This forces the plant to branch and will also produce fuller growth from your petunias. Leaving too much on your petunia can stifle growth and not do enough to promote branching.
Keep an eye on your petunias. There can be things such as snails, slugs, and aphids that feed on the foliage. Not only that, these little critters can leave your petunias looking weak and ragged and possibly make them unsalvageable.
If you do have a minor infestation of aphids, you can get rid of them with an insecticidal soap. If you have slugs or snails that permeate your garden, try setting out traps that will destroy those that feed on your plants.
Don’t be afraid to get a bit drastic in your pruning. If your petunias are severely leggy or deteriorated, you may need to prune them all the way back to the lip of the pot.
With as awful as petunias have to be to require this kind of pruning, it can’t get any worse.
Be Patient
When you have taken all of the necessary steps to prune them back, revitalize the soil, mulch, and fertilize, you have built the necessary foundation for success that your petunias need to begin blooming once again.
When that is done, all you need to do is keep up with your feeding and watering while trying to remain patient. This can be difficult to do, especially if your petunias are weathered and leggy enough that it becomes a real eye sore.
But with that consistent watering and feeding, as well as any additional necessary pruning where you see fit, your petunias should begin to rebound. It should not be terribly long before they begin to bloom once again, bringing with them that vibrant color that makes them a favorite to begin with.
Keep in mind that not every petunia is salvageable. There are some that are leggy and weathered past the point of saving and that is okay. Do your best to prune them back and give your petunias a chance to bounce back.
Even if you do lose some of your petunias, it will arm you with the knowledge and experience that you need to save some in the future. Being able to recognize the signs of dying petunias and what to do when that happens can go a long way toward being able to save them should you run into bad petunias again in the future.
Your petunias are meant to provide brightness and color to your home or garden. Give them a little extra love and you can bring some of the most weathered petunias back from the brink.
Growing up with a mom who filled her home (inside and out) with all sorts of plants, Lisa got her start in gardening at a young age. Living now on her own with a home and yard full of plants (including an indoor greenhouse), she shares all the gardening tips she’s gained over the years.
David Strader
Saturday 29th of July 2023
Thank you. Great information.