Petunia Hanging Basket Care – How to Grow Enviable Displays!

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You want the best-looking petunia hanging basket around – I know you, we’re the same. We want big, bold, colorful, fully in-bloom hanging planters, and we want them yesterday. Having the know-how to care for petunias in hanging baskets can distinguish between mediocre plants and stunning full displays.

A very full very colorful hanging basket of petunias.

As a rule, petunias will last and bloom all summer in a hanging basket if they have proper care. The following article will provide all the information you need to grow envious petunia hanging baskets through the growing season. We have everything you need to know, from how many plants per basket to how much sun, water, and fertilizer, and the expert tips to make your hanging baskets the envy of your street.

Table of Contents

    Start By Checking Your Hardiness Zone

    Petunia plants are classified as tender perennials in USDA zones 9-11. In those warmer zones, petunias will come back year after year. However, petunias are grown as half-hardy annuals that die back after a hard frost in most regions. 

    Petunias originate from South America, so they prefer a warm climate. That doesn’t mean you can’t grow them in zones below 9; it just means you will need to plant fresh petunias every year. So plant petunias in your garden beds, window boxes, or hanging baskets to enjoy their wonderful flowers all summer.

    To check your hardiness zone you can use this interactive map if you live in the United States, and these maps if you live in Canada.

    Provide at Least Six Hours of Sunlight Per Day

    Petunia flowers require at least 6 hours of direct sunlight a day. 

    To encourage the best bloom, place your petunia hanging basket in a spot that receives full sun for at least half of the day. Too much shade will discourage blooming. 

    A very full hanging basket of red petunias.

    Set a Daily Watering Schedule

    The most important step to petunia hanging basket care is proper watering. Petunias in baskets require regular watering at least once a day. In addition, they may need to be watered twice a day in hotter regions or warmer weather.

    You will want to water petunias deeply to avoid growing plants with shallow roots.

    Check the top inch of soil before watering to ensure the soil is dry.  Frequent unnecessary waterings can lead to a fungal disease like root rot, so avoid providing too much water. 

    Fertilize and Feed Petunias Every Week

    Petunias are heavy feeders and, when planted in a container, will very quickly deplete the nutrients in the soil.

    It’s a good idea to add a slow-release fertilizer at the soil surface after planting or when you bring your containers home.  A slow-release balanced fertilizer will provide nutrients over many weeks. 

    Liquid fertilizer will work as well, but you will lose much of the fertilizer while watering as excess will drain out of the bottom of the pot.  

    A lovely lilac colored petunia hanging basket.

    Choose a Potting Soil with Lots of Organic Matter

    The correct soil type is essential for healthy petunia plants that flower throughout the season. 

    The soil should have lots of organic matter, with additions like vermiculite for water retention, peat, or coconut choir for good drainage. 

    It’s best to purchase soil specifically for potted plants, like pro-mix. 

    Choose A Sturdy Basket With Good Drainage

    When choosing a basket for your petunias, you need to ensure the pot is big and sturdy enough (at least 10 inches) and that it has adequate drainage holes. 

    You can plant your petunias in almost any vessel and they will grow, but small pots under 10 inches will dry out incredibly fast and will require constant monitoring during the summer.  

    For additional drainage, it is a good idea to add an inch of small gravel or rocks to the bottom of the basket. Adding small stones or gravel is a great way to ensure excellent drainage. 

    Baskets of of multi-colored petunias on a greenhouse rack.

    Plant Both Milliflora and Multiflora Petunias for the Best Displays

    The best petunia varieties for your hanging baskets are milliflora and multiflora petunias. These two types of petunias have trailing growth habits and bloom intensely. The flowers will drape and hang over the sides of hanging baskets and create a dramatic display.  They also hold up better in heavy rain and generally inclement weather. 

    For extraordinary hanging baskets, I recommend any of the wave petunias. 

    With that said, you can also plant other petunias in hanging baskets. Some of the bushier petunias will create mounds of flowers that do not hang but have a neat growing habit that you may prefer. 

    It’s important to note that Grandiflora petunias can get spindly mid-summer, especially in hanging baskets, and will require heavy pruning to encourage more blooms. In addition, the Grandiflora petunias require a bit more care (like deadheading during the season), so I try to avoid planting them in hanging baskets for those reasons. 

    Plant the Correct Number of Petunias for Your Basket Size

    The general rule for standard petunias is to divide the size of your basket by two, and that is the number of petunias required.  For example, a 10-inch basket would require 5; a 14-inch basket needs at least 7.  

    The exception is the large flowering wave petunias for wave petunias plant, approximately 3 per 10-inch basket.  

    If you’re planting your flower baskets, remember most garden centers start their petunia baskets in early spring, so they have big beautiful displays bursting with flowers at the start of the growing season. 

    If you buy your petunias for your baskets in late spring, the flowers will be just getting started, and your baskets may look sparse. Do not let this bother you. Those plants will fill in just fine, and that basket will be beautiful in a few weeks. 

    Choose a Sheltered Spot with Plenty of Sun

    It’s a good idea to pick a site sheltered from strong winds.  Strong winds can do a great deal of damage to your petunia hanging baskets. 

    You also want to choose a site that has adequate sunlight. For example, placing baskets on shaded porches can cause the flowers to be less prolific. 

    And lastly, be sure to hang those baskets high enough if deer are a problem in your area. Deers love to eat petunias, but raising them out of reach is a great way to keep your flowers from being a deer’s lunch.

    A full healthy purple petunia hanging basket.

    Deadhead Regularly and Prune in Late Summer

    Deadhead and prune your petunias regularly to keep them looking good all season. For big, bushy petunia baskets, the recommendation is to pinch out the growing tips when the plants are about 6 inches tall. Pinching will encourage branching and bushy growth.

    You can pinch again after the first flower flush for even more flowers! If plants become leggy and stop blooming during the hottest days of summer, you can cut them back and add fertilizer and water to promote new growth.

    Deadheading petunias (the process of removing old flowers from petunia plants) will also help encourage new blooms.

    Expert Tips

    To keep hanging petunia baskets beautiful follow these best practices:

    1. Sunlight: Ensure they get 6-8 hours of direct sunlight daily for optimal blooming.
    2. Watering: Water thoroughly once the top inch of soil feels dry, preferably in the morning to prevent diseases.
    3. Fertilization: Feed every 1-2 weeks with a liquid, water-soluble fertilizer to support continuous blooming.
    4. Deadheading and Pruning: Regularly remove spent blooms and prune back leggy stems by up to one-third to encourage bushier growth and more flowers.
    5. Air Circulation: Space baskets to ensure good airflow, reducing disease risks.
    6. Pest Control: Watch for pests like aphids and spider mites and treat them with insecticidal soap or neem oil.
    7. Variety Selection: Choose trailing or spreading varieties like Wave, Supertunia, or Surfinia for best performance in baskets.
    8. Soil Quality: Use a high-quality potting mix with good drainage to prevent root rot.
    9. Moisture Retention: Add a mulch layer or use self-watering baskets to help soil retain moisture, especially during hot weather.
    10. Acclimatization: Gradually acclimate petunias to outdoor conditions to reduce shock and stress.
    11. Look For Young Compact Plants: When purchasing petunias at your local nursery in spring, look for young compact plants. You want plants with good foliage color but few flowers. Choosing petunias this way may seem odd, as most people want to see blooms immediately, but plants in full bloom may be root-bound.

    FAQ

    What type of petunias are best for hanging baskets?

    Wave Petunias: Known for their ability to spread and fill space, making them perfect for lush baskets.
    Surfinia Petunias: Highly prolific bloomers with a trailing habit, ideal for cascading over the sides of baskets.
    Million Bells (Calibrachoa): Though not true petunias, they resemble miniature petunias and are excellent for hanging baskets due to their small size and abundant flowers.

    What should I do with my petunias as the weather cools?

    Petunias are annuals in most climates, meaning they complete their life cycle in one season. As temperatures drop, their performance will diminish. You can extend their display by moving baskets indoors if nights become too cold, but eventually, it’s best to compost the plants and plan for next season’s display.

    How often should I water petunias in hanging baskets?

    Petunias in hanging baskets need to be watered more frequently than those in the ground due to exposure to air on all sides, which can dry out the soil faster. During hot weather, watering daily may be necessary, especially for baskets hanging in full sun. It’s crucial to ensure the basket has good drainage to prevent root rot.

    Do petunias in hanging baskets require fertilization?

    Petunias are heavy feeders and benefit from regular fertilization. Use a water-soluble fertilizer designed for flowering plants every 1-2 weeks. Alternatively, a slow-release fertilizer can be applied at the beginning of the season, but liquid fertilizers often provide more consistent results for plants in baskets.

    How much sunlight do petunias need?

    Petunias thrive in full sun, requiring at least 6 to 8 hours of direct sunlight per day. However, in extremely hot climates, some afternoon shade can help prevent the flowers from fading or wilting.

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    Final Remarks

    Growing lovely hanging baskets will take a bit of extra effort on your part but they are worth the time. Big bodacious displays or petunias that dangle from patios and hooks are always so welcome. Nothing quite says summer like those parades of flowering baskets. So give your hanging baskets the love and attention they need this season.

    We hope you learned everything you need to know about petunia hanging basket care. We have so much more information to share with you about flower gardening, though, so if you’re looking for inspiration or even ideas, check out these posts!

    Author: Laura Kennedy

    Writer & Owner of Little Yellow Wheelbarrow

    Laura is a highly skilled gardener and fervent flower enthusiast. Despite her playful battle with plant spacing guidelines, Laura’s work inspires gardeners to create thriving, beautiful spaces that reflect both creativity and sustainability.

    Editor’s note: This post was published on March 3, 2022, and was updated on February 9, 2024. The update includes a refreshed format, expert tips, FAQs, and new image-directed related posts.