If your petunias looked spectacular in late spring but have since slowed down, or stopped blooming altogether, don't give up on them.
With a few simple care tweaks, including more frequent feeding and proper deadheading, you can keep petunias covered in flowers well into autumn. Read on for a few essential tips to give your blooms a new lease of life this summer...
Find a bright spot
While petunias can tolerate partial shade, they will bloom more in full sun. About 6 to 8 hours of sun a day is ideal. That said, you should keep an eye on temperatures in the summer. If the summer heat becomes intense, move them to a shadier spot to prevent wilting flowers and sunburnt leaves.
Water regularly
In the hot summer months, petunias need regular watering. Petunias growing in hanging baskets and containers may need watering daily during periods of extreme heat, while those planted in the ground usually require less frequent watering. Water deeply whenever the top 2–3cm of compost or soil feels dry rather than giving plants a light daily sprinkle.
Add fertiliser
Petunias produce flowers continuously throughout summer, so regular feeding can help sustain their display. The Royal Horticultural Society (RHS) recommends using a “potassium-rich liquid fertiliser, such as tomato feed” every couple of weeks to encourage more flowers, particularly for bedding plants and those growing in containers.
Remove spent blooms
As flowers fade, you can remove them to encourage new growth and keep your plants looking fresh. You want to remove faded flowers before they have a chance to set seed. This encourages the plant to put its energy into making new blooms instead. When deadheading, remove both the flower and the small swollen seed pod just below it.
There are some modern hybrid varieties that are “self-cleaning,” which means that the plants shed their spent flowers, so you don’t have to do it.
Trim back leggy plants
By midsummer, petunias can become leggy, sparse and produce fewer flowers. If stems become gangly, trim them back by about one-third, then water well and fertilise. New growth should appear within a couple of weeks, producing a fuller plant and more blooms.
Know your petunias
With their cheerful flowers and graceful trailing vines, petunias are made for containers, window boxes and hanging baskets. They also look great planted in the ground, where they can form billowy mounds of bright colour. These plants are ideal for gardeners of any experience level because they're so easy to grow. With a little extra care, they can keep flowering throughout summer.
Petunias come in a dizzying array of colours and petal types, but they typically fall into four categories:
- Milliflora: Small plants with tiny flowers
- Multiflora: Small flowers in large amounts
- Grandiflora: Large flowers
- Spreading varieties: Plants with trailing vines that are ideal for hanging containers and large spaces, like flower beds
Gardening tools
Squirrel Flower Scissors in Leather Pouch
Implementations Atik - Mini Rake
Fieldware Co Pocket Apron - Classic Waxed Cotton
Mytri Designs Tamra Copper Floor Planter
Gardeners Hand Salve
The Little Oak Company Painted Garden Label/Marker
Lisa Cericola (she/her) is a writer and editor who specializes in travel, food, and culture. A South Florida native, Lisa lived in New York City for 15 years and now resides in beautiful Birmingham, Alabama. She has been an editor at Southern Living and Food Network Magazine and writes for numerous publications including Garden & Gun and Late Checkout. When she’s not working on a story, or planning her next trip, Lisa is likely making and selling small-batch olive oil granola at her local farmers market.
