People all over the world love dahlias, but they can be just as mysterious as they are beautiful. These popular perennial flowers are grown all across the world, and there are over 50,000 different cultivars. Because they are different, this can cause a lot of questions, especially about how much sun they need.
You’re not the only one who wants to grow dahlias in their garden this year; now you just need to figure out where to put them. When it comes to the sun vs. shade debate, the answer isn’t entirely clear cut, due to how many varieties of dahlias there are.
Before we talk about how much sun dahlias need, you’ll learn about the genus and the hardiness zones where they can live year after year. There will also be information about where to put dahlias so they get enough sun if you choose to grow them in pots. Let’s jump in!.
The short answer is that most dahlia cultivars prefer full sun, to partial sun. This means they need at least 6 to 8 hours per day in order to do well. Dahlias grow perennially in USDA Hardiness zones 8-11. But if it regularly gets above 100°F, you’ll need to plan for some afternoon shade because that’s when the temperature is at its highest.
Can Dahlias Grow in Partial Shade? A Guide to Successful Growth
Dahlias are absolutely breathtaking flowers that can transform any garden into a kaleidoscope of color With their immense diversity of sizes, shapes, and hues, it’s no wonder they are one of the most popular flowers for gardens and cut flower arrangements However, there is often confusion around how much sunlight dahlias need to thrive. Can dahlias grow in partial shade? Let’s find out!
Do Dahlias Prefer Full Sun or Partial Shade?
Dahlias are generally considered full sun plants, meaning they thrive in areas receiving at least 6 hours of direct sunlight per day. This allows them to produce the most prolific blossoms. However, some varieties are more tolerant of partial shade than others.
Partial shade refers to areas receiving between 3-6 hours of sunlight per day, either in the morning or afternoon. While dahlias prefer full sun, they can adapt to partial shade depending on the variety. Factors like climate, location, and microclimates created by other plants and structures in the garden also play a role.
- Full sun (6+ hours direct sunlight) is ideal
- Partial shade (3-6 hours) can be tolerated by some varieties
- Success depends on variety, climate, and other environmental factors
Best Dahlia Varieties for Partial Shade
If your garden only gets a few hours of sunlight, focus on these dahlia varieties that tolerate partial shade well:
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Mystic Dreamer: A petite variety with unique bicolor flowers in shades of pink and lavender.
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Karma Choc: Large, dark purple blooms on a compact plant. Its darker coloring allows it to absorb more light.
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Bishop of Llandaff: Dark foliage and vivid red flowers that pop against the leaves.
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Arabian Night: A later bloomer with deep burgundy blossoms and near-black foliage.
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Moonfire: Pale yellow flowers complement this variety’s variegated foliage.
There are also dwarf dahlia varieties under 3 feet tall that adapt better to less intense sunlight, like Dahlia ‘My Hero’ and ‘Alfred Grille’.
Growing Dahlias in Partial Shade Successfully
While dahlias are flexible, they still require some specific care when grown in partial shade. Follow these tips for the best results:
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Choose the sunniest spot available, even if it’s just a few hours of morning or afternoon sun.
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Prepare the soil well by mixing in compost or well-aged manure to improve drainage and nutrients.
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Water carefully and allow soil to dry slightly between waterings to prevent tuber rot.
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Stake or trellis plants to support extra tall growth towards the sun.
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Pinch back leggy growth early in the season to encourage bushier plants.
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Fertilize regularly with a balanced flower fertilizer to provide extra nutrients.
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Watch for slugs, snails, and mildew which thrive in shade and dampness.
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Mulch around plants to conserve moisture and suppress weeds.
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Remove spent blooms to encourage continuous flowering into fall.
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Lift tubers in fall if you live in zones colder than 8; store in cool dry place for replanting.
Maximizing Sunlight in a Shadier Garden
If your landscape lacks sufficient sun exposure, there are several ways to optimize what light your plants do receive:
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Remove overhanging branches, trees, or obstructive plants that cast too much shade.
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Trim back plants along the garden’s south side to let more sunlight filter through.
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Use light reflective materials like white-painted fences or walls to bounce sunlight around.
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Add gravel beds, pavers, or tiles around plants to reflect light upwards from the ground.
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Use taller trellises, obelisks, or supports to elevate plants into sunnier spots.
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Move potted plants around into sunnier spots through the day.
Alternative Shade-Loving Flowers
If your garden is heavily shaded, you may have better luck with flowers naturally adapted to lower light. Some alternatives to dahlias include:
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Astilbe: Feathery plumes in white, pink, red, or purple
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Begonias: Vibrant rose-like flowers and colorful foliage
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Coleus: Grown for its vividly patterned leaves
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Impatiens: Bloom in a wide range of bright colors all season
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Hostas: Feature attractive foliage in different shapes and variegations
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Heucheras: Prized for their ruffly foliage in silver, green, and burgundy
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Caladiums: Tropical-looking plants with dramatic, colorful leaves
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Tuberous begonias: Bold double blooms in bright citrus shades
The Takeaway
While dahlias thrive in full sunlight, many varieties can adapt to partial shade with proper care and preparation. Seek out tolerant varieties, maximize sunlight, and provide ideal growing conditions for the best success with dahlias in shadier spots. If your garden lacks adequate sunlight, you can opt for natural shade-dwellers as fun alternatives to dahlias. With an appreciation of their light requirements and some patience, you can find the perfect way to work dahlias into nearly any garden.
Where Do Dahlias Grow Naturally?
Dahlias can be found in the wild in Ecuador and Guatemala’s mountainous areas, in oak and pine forests.
Dahlias also grow naturally in Guatemala and Colombia, which are close by and have mountainous areas that share Mexico’s warm climate. The dahlia plant does well in oak and pine forests, which shows how it has changed over time to fit in with its natural environment.
Adaptation was necessary for the plant to protect itself from losing moisture in the harsher conditions. It’s adapted to handle like dry heat and strong winds, that can affect the nations of Central America.
In What Soils Do Dahlias Grow Best?
Dahlias grow well on loamy soils, sandy soils, and fertile black soil.
Dahlias are like most plants in that they prefer soils that are loose, fertile, and well-drained. However, dahlias will not survive cold North American winters. People who garden should usually wait to plant tubers until the soil warms up in the spring and there is no chance of frost. Adding fertilizer, manure, or compost can help enrich the soil with nutrients. It is preferable to plant dahlias in an area where soil won’t become soggy or compact over time.
Soils are a critical factor in planting and growing dahlia tubers. Dahlia tubers love well-drained dirt. So, if you need to plant dahlias in clay or heavy soil, add peat or sand to help the soil drain. Pre-packaged garden soil and mulch can potentially harm the tubers and prevent drainage. So, it’s best to avoid using them altogether.
Do dahlias like sun or shade?
FAQ
How many hours of sun does a dahlia need?
Which dahlias grow in shade?
Do dahlias grow better in pots or the ground?
Where is the best place to plant dahlias?
What is a partial shade Dahlia?
Partial shade Partial shade refers to areas where dahlias receives filtered sunlight for a portion of the day, with limited direct sunlight exposure. A partially shaded location receives less than 6 hours but at least 4 hours of sunlight daily, usually in the mornings with less intense light and heat.
Do dahlias need shade?
Dense-shade plants love the dark the most, needing no direct sunlight. When it comes to dahlias, they prefer full sun, in any environment that stays below 100°F. In environments that get hotter than that, they need partial shade. This means it’s best to provide them some shade for the hottest part of the afternoon.
Do dahlias need full sun?
Full shade plants need less than an hour of direct sunlight per day. Dense-shade plants love the dark the most, needing no direct sunlight. When it comes to dahlias, they prefer full sun, in any environment that stays below 100°F. In environments that get hotter than that, they need partial shade.
Do dahlias stop flowering if the Sun is too hot?
However, if the sun is too hot and the temperatures are too high, the plants may stop flowering. Choose a planting location that offers half sun and half shade instead of the full-day sun to protect your dahlias from excess heat. Ideally, your plants will get full morning sun and shade in the afternoon.
Why do dahlias grow in shady areas?
dahlias planted in shady areas benefit from the protection provided by surrounding trees or structures. The shade helps break the strength of strong winds, preventing them from damaging or uprooting the delicate branches of the dahlias. This protection also contributes to their overall health and longevity.
Do dahlias need staking?
Most dahlias need staking. To prevent injury to the tubers, put the support in the ground before planting the dahlias. Dahlias need full to partial sun. Full sun encourages upright plants that need less staking, but these plants will flower in part shade.