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Petunias are beautiful and iconic flowers for summer, but how long can you expect to have them around to enjoy? We wanted to know, too, so we hit the books on petunia bloom cycles.
We were so excited to find out that petunias can and do bloom all summer! However, petunias do need a bit of TLC to make it that long. Petunias need plenty of sunlight, regular water, fertilizer, clipping, deadheading, as well as pest control to stay blooming and beautiful all summer.
Okay, so there’s a bit to keeping flowers on your petunias. But you need a few more details, right? Don’t worry. We’ve got you covered with plenty of information below.
How to Keep Your Petunias Blooming
You know you can’t just stick a basket or pot of petunias on your porch in the spring and then walk away, never touch them again, and yet still have bushels of blooms all summer. Here are a few tried and true tips for keeping your plants happy and flowering.
Petunias love some sun, and it’s best to keep them content if you want a lot of blooms. They do best in full sun, but they can do well in partial sun as well, though they don’t bloom quite as much. For the best blooms, make sure your petunias get at least 6 hours of sunlight a day.
Water, But Not Too Much
Petunias are not dry weather plants. They need water, and regularly. But be careful and don’t spray the blooms! When the flower is hit with water it closes up and gets mushy, which isn’t really the look you were hoping for.
They don’t like to swim, though, so make sure that the soil they are in is well-drained. Weekly deep watering is ideal for petunias you have planted in the ground, while daily watering may be needed for the spreading varieties or for container-planted petunias. An example of a hanging basket with good drainage for petunias can be found below.
To find these baskets, check Amazon here.
Petunias love their fertilizer, and it’s a good idea to feed them if you want an abundance of blooms. If you plant the petunias yourself, make sure and fertilize the soil well beforehand. This will ensure strong, healthy growth from the beginning, and the healthier the plant, the better for blooms.
For plants that are already in the ground or container, use a combination of organic and time-released fertilizer every three weeks or so for the best results. The time-released will wear out about the time the organic fertilizer gets active in the soil, so doing this will keep your plant happy and well-fed on a continual basis. Below are a couple of examples of good, well-balanced fertilizer for petunias:
To find this slow-release fertilizer on Amazon, click here.
This fertilizer is available on Amazon here.
Once a flower fades a seed pod starts growing in its place. Deadheading removes these seed pods before they mature so the plant will keep producing flowers. Check your plant regularly, every day or so, for fading blooms and deadhead any you find to force the plant to keep flowering.
Keep the Stems Short
A petunia blooms at the end of the stem and only at the end of the stem. If you let it grow too long, you’ll have too much stem and not enough blooms, making it look a little awkward and leggy. To avoid this, clip your stems back.
You can start this as soon as you get home with your new plant. Check the stem lengths and if any are at 8″ or longer either pinch or clip them in half. You can do them all at once or clip three to four a week. Doing this will keep your petunias full and bushy instead of stretched out and spidery.
You can find clippers like this on Amazon here.
Keep it Free of Pests
No plant likes being nibbled on by little critters or fungal invasions, and petunias are no exception. Gray mold and rot are big problems in rainy areas. If you live in a wetter climate, check the variety of petunia before you bring it home and make sure it’s resistant to the weather.
Aphids frequently snack on the leaves of the plant, but a good rinse of the stems (not the blooms, remember?) with a strong blast of water will get rid of them. There’s also budworm caterpillars to watch for as well. They normally appear in late June through July and they love the flower buds on petunia plants. Bad news for our pretty gardens and patios, right? The good news is they’ll leave in July, but if they’re really bad you can pick up some Bt pesticide to get rid of them.
To find Bt pesticide on Amazon, click here.
How do You Deadhead Petunias?
To deadhead a petunia you can’t just pull off the petals and call it done. Instead, reach behind where the petals are and feel for the swollen bump right below them. This is the seed pod that you want to get rid of. Once these grow to maturity it will send a signal to your plant that the stem has done its job and it won’t produce any more flowers. Which would be fine if we wanted only a few blooms, but we want months of pretty flowers. Either pinch the flower and seed pod off the stem or use a set of clippers to cut them off. And then you’re set! Your petunias will keep producing flowers happily all summer.
Do Petunias Like Hot Weather?
Yes! Petunias love to be warm and toasty. They can not tolerate the cold and will die once temperatures drop to 30 degrees and below, but hot weather is perfect. They won’t even germinate until the environment they’re in starts hovering between 70 and 80 degrees, making them a true summer plant. As long as you keep them well watered they’ll be happy to hang around all summer.
How Much Heat Can Petunias Tolerate?
Petunias love warm weather, but even the most heat-loving plants can only take so much. Once temperatures start rising above 85 degrees Fahrenheit and stay there you’ll notice your petunias wilting and thinning out. To combat this cut the stems back by 2/3 and give them a good dose of fertilizer. Keep them well watered and once the temperatures start dropping again your petunia plant will start flowering once more.
Keeping petunias flowering all summer might seem like a hard task, but as you can see it’s fairly simple. Sunlight, water, and fertilizer work wonders in keeping a petunia plant happy and healthy. Keeping the stems short and deadheading also make sure there are plenty of ends ready and willing to produce blooms. Just follow this guide and you’ll be enjoying beautiful petunia blossoms all season long.