As the days become shorter and the weather threatens to cool down, it’s time to start making some major changes in our gardens. And if you grow any flowering plants, you may already be thinking about which ones you need to deadhead this autumn.
That said, there are plenty of flowers that actually do not need to be deadheaded in September—according to experts, it’s typically best to let these plants go to seed during the fall instead of deadheading them.
To learn more about which flowers you shouldn’t deadhead in the Northern Hemisphere in September, Parade spoke with two gardeners: Melissa Keyser, a gardener, a landscape and garden designer and the Founder and Lead Designer of Maine-based landscape design studio Cultivating Wild, and Ryann Morris, a gardener, Ayurvedic Chef, Culinary Wellness Educator and Founder of Food Brilliance.
“I’ve learned not to look at a fading flower as the end of a plant’s usefulness,” Morris tells Parade. “Sometimes it’s actually the beginning of its next purpose.”
Keep reading to learn more about deadheading, why saving certain plants from deadheading is important and which five flowers you shouldn’t deadhead in September.
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What Is Deadheading a Plant?
To deadhead a plant is to remove any dead or dying flowers from a living plant, per the Royal Horticultural Society (RHS). Deadheading a plant helps redirect the plant’s energy into stimulating flower growth.
If plants in your garden or flowerbed have dead or dying blooms, and you choose not to deadhead them, then you are letting the plants go to seed, which means the plants will use their energy to produce seeds instead of flowers.
Why It’s Important to Save Certain Flowers in September Instead of Deadheading Them
“When we stop deadheading certain plants later in the season, we give them the opportunity to complete their natural cycle,” Morris explains. “The flowers can continue supporting pollinators, the developing seed heads can provide food for birds and mature seeds can often be collected and planted again.”
“When it comes to considering deadheading perennials,” Keyser adds, “I like to consider three things: how will it look in winter when everything is dead and brown, what kind of support can it provide to wildlife and how easily will this plant reseed.”
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In Maine, where Keyser lives, there are often several weeks between the first frost and the first heavy snow—and letting certain plants go to seed is especially beneficial during this time period.
“For this gap of time, having structural elements and movement from dried seed heads provides visual interest and paints the garden in subtle shades of earth tones,” she explains. “As an ecological landscape designer, I also want to make sure my gardens are providing more than just looks, but are a way to steward the wildlife around us.”
5 Flowers You Should Stop Deadheading in September, According to 2 Gardeners
1. Coneflowers and Black-eyed Susans
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Keyser says that coneflowers (Echinacea) and black-eyed Susans (Rudbeckia), two flowers that are closely related to one another, are some of her “favorite flower heads to leave in the fall for the birds”—namely, goldfinch.
“You might have a few volunteer plants come up in the spring, but they are easy to pull or transplant if they aren’t in an ideal location,” she explains. “The Rudbeckias usually fall down once we get some snow, but the Echinaceas stay standing for quite some time and the spiky seed heads collect ice crystals and sparkle.”
Morris agrees, noting that she prefers to leave her Echinacea plants alone for the winter. “Unlike some of the herbs I grow primarily for the kitchen, I leave Echinacea heads standing because they continue to have value in the garden long after the petals are gone,” she explains.
“The seed heads can become a food source for birds, particularly finches, and they add beautiful structure to the garden as the seasons change,” adds Morris. “I think it’s a wonderful reminder that a plant doesn’t stop contributing just because its prettiest stage has passed.”
Related: 8 Flowers You Should Plant Right Now for Gorgeous Fall Color
2. Stonecrop
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Keyser prefers “to leave the flowers” of her Autumn Joy Sedum, aka stonecrop plants.
“The flowers turn a lovely bronzed brown and the stems stand up under snow, adding texture and dimension to the landscape,” she says.
3. Tulsi
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“Tulsi is one herb I intentionally stop cutting back and allow to flower and go to seed,” says Morris. Tulsi is also commonly known as holy basil.
“Earlier in the growing cycle, I may pinch off the flowers to encourage the plant to keep producing leaves, but later I want to let the plant do what it naturally wants to do next,” she adds. “The flowers support pollinators, and once the seed heads fully mature, I can collect those seeds and grow tulsi again.”
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4. Marigolds
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When Morris wants to encourage more flowers, she will often deadhead marigolds (Calendula). However, as summer comes to an end, she opts to “intentionally leave some of those flower heads alone,” adding that “Once the flowers fade and the seed heads are allowed to fully mature, I can collect the seeds and plant them again.”
“Calendula is such a useful herb to have in the garden,” she notes, “and I love being able to participate in the entire life of the plant rather than only enjoying it while it’s in bloom. Leaving some flowers to go to seed also means I’m already thinking about what I want to grow in the next season.”
5. Dill
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“With dill, I stop removing the flower heads once I’m ready to let the plant go to seed,” says Morris. “Earlier in the season, removing flowers can help keep the plant focused on producing the fresh dill leaves we use in the kitchen.”
But as the weather starts to cool, Morris chooses to leave her dill plants’ “beautiful umbrella-shaped flowers alone,” as they eventually produce dill seed. Morris loves using dill seeds in in Ayurvedic cooking, as many believe the seeds can support digestive health.
“This is one of my favorite examples of why I don’t automatically remove something from a plant just because it has started flowering,” Morris says. “Dill gives us its leaves, its flowers support beneficial insects and pollinators and then its seeds bring us right back into the kitchen.”
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Sources:
- Melissa Keyser, a gardener, a landscape and garden designer and the Founder and Lead Designer of Maine-based landscape design studio Cultivating Wild.
- Ryann Morris, a gardener, Ayurvedic Chef, Culinary Wellness Educator and Founder of Food Brilliance.
- Deadheading plants. Royal Horticultural Society.