Lilac, Rhododendron, Spirea, and Viburnum are flowering plants similar to Hydrangea and you cannot distinguish them easily. Hi, I’m a horticultural consultant and here compare their characteristics with their images and show you how to distinguish them easily.
You may think what does it matter if I can identify plants similar to Hydrangea? Based on my experiences Hydrangea and its lookalikes may have different caring needs, so, to plant them in the right place in your garden and grow them healthy, you must know who is your lovely flowering plant.
In addition, as you may know, the prices of Lilac, Rhododendron, Spirea, Viburnum, and Hydrangea are different in garden centres and may have an impact on your decision to buy them. So, here, I first help you to identify every above plant correctly, tell you how to distinguish them from Hydrangea and finally compare their caring needs.
But before diving into Hydrangea lookalikes, let’s Identify it correctly, and keep reading.
Hydrangea (Hydrangea spp.):
Hydrangea is a dazzling shrub with a more open, spreading form, varying in height from 3 to 10 feet depending on the type. As you know, Hydrangea is most famous because of its stunning blooms. This attractive plant has large, rounded clusters (known as inflorescences) of flowers that can be white, pink, blue, or purple, depending on soil pH and variety. Hydrangea leaves are broad and ovate with a serrated edge, usually dark green.
you can also find more shrubs with large clusters of white flowers in my other post. By and large, let’s find what flowering plants are similar to Hydrangea.
Lilac Plants Similar to Hydrangea
Scientific name: Syringa vulgaris
- Flowers: Small, tubular blooms clustered in dense, fragrant panicles, typically in shades of purple, lavender, or white.
- Leaves: Heart-shaped, dark green leaves with a smooth texture.
- Growth Habit: Shrub or small tree with a rounded, dense form, reaching about 8-15 feet tall.
Distinguishing Between Lilac and Hydrangea
- Flowers: Lilacs have smaller, more fragrant clusters, while hydrangeas feature larger, showier blooms.
- Leaves: Lilacs have heart-shaped leaves, while hydrangeas have broader, serrated leaves.
- Growth: Lilacs tend to be more upright and dense, whereas hydrangeas can be more spreading and varied in size.
Compare the Caring Needs of Lilac with Hydrangea
Sunlight
- Lilac: Prefers full sun (at least 6 hours of direct sunlight per day) for optimal blooming.
- Hydrangea: Can vary depending on the type. Many prefer partial shade or filtered sunlight, especially in hotter climates, while some varieties tolerate full sun.
Watering
- Lilac: Generally drought-tolerant once established, but benefits from regular watering during dry periods. Ensure the soil is well-draining to prevent root rot.
- Hydrangea: Requires more consistent moisture. The soil should be kept evenly moist but not soggy. Hydrangeas may need more frequent watering, particularly in hot or dry conditions.
Soil
Lilac: Prefers well-draining soil, typically slightly alkaline to neutral. Good drainage is crucial.
Hydrangea: Soil preferences vary by type. Many thrive in well-draining, organic-rich soil that is slightly acidic to neutral. Soil pH can influence flower color in some varieties. ( read my other post about the best potting soil)
Fertilizing
- Lilac: Needs minimal fertilization. A balanced, slow-release fertilizer applied in early spring can support growth and blooming.
- Hydrangea: Benefits from regular feeding during the growing season. Use a balanced or specific hydrangea fertilizer to encourage healthy growth and blooms.
Pruning
- Lilac: Best pruned immediately after flowering to avoid cutting off next year’s buds. Prune to shape and remove any dead or diseased wood.
- Hydrangea: Pruning needs depend on the variety. Some bloom on old wood and should be pruned after flowering, while others bloom on new wood and can be pruned in late winter or early spring.
Pests and Diseases
- Lilac: Generally low-maintenance with few serious pest or disease issues. Watch for powdery mildew and aphids.
- Hydrangea: Can be susceptible to pests such as aphids and spider mites, and diseases like powdery mildew and leaf spot. Proper spacing and airflow help prevent issues.
Winter Care
- Lilac: Hardy and generally low-maintenance in winter. Mulching can help protect the root zone from extreme temperatures.
- Hydrangea: Winter care varies by type. Some may need protection from frost, particularly those that are less cold-hardy. Mulching and covering the base can help protect the plant.
Rhododendron Plants Similar to Hydrangea
- Flowers: Rhododendrons produce large, showy clusters of flowers that can vary widely in colour, including shades of pink, purple, red, white, and yellow. The flowers are often tubular or bell-shaped, and they bloom in dense, rounded trusses. (read my other post about plants with clusters of white flowers).
- Leaves: Rhododendron leaves are typically large, leathery, and evergreen. They are usually dark green but can also be lighter shades or have a slightly reddish tint. The leaves are often glossy and may have a somewhat wrinkled texture.
- Growth Habit: Rhododendrons are usually shrubs or small trees with a dense, bushy growth habit. They can range in size from 3 to 15 feet tall, depending on the species and growing conditions.
Distinguishing Between Rhododendron and Hydrangea
Flowers:
- Rhododendron: Produces dense clusters of tubular or bell-shaped flowers, often with a more uniform color range.
- Hydrangea: Features large, rounded clusters of flowers, with a variety of colour changes influenced by soil pH, and typically have a more rounded appearance.
Leaves:
- Rhododendron: Large, leathery, evergreen leaves with a glossy texture and darker green color.
- Hydrangea: Broad, ovate, deciduous leaves with a serrated edge and a generally rougher texture.
Growth Habit:
- Rhododendron: Dense, bushy, and evergreen, often with a more compact form.
- Hydrangea: More open and spreading, with a deciduous habit that changes with the seasons.
Seasonality:
- Rhododendron: Evergreen leaves provide year-round interest, and the flowers typically bloom in spring.
- Hydrangea: Deciduous leaves fall in autumn, and the flowers bloom from summer to fall, depending on the variety.
Caring Needs Comparison: Rhododendron vs. Hydrangea
Sunlight
- Rhododendron: Prefers partial shade to full shade. It can tolerate some direct sunlight but generally thrives in environments with dappled sunlight or morning sun and afternoon shade. Too much direct sunlight can lead to leaf burn.
- Hydrangea: Preferences vary by species. Many Hydrangeas do well in partial shade, especially in hotter climates, while some varieties can handle full sun. Generally, morning sun with afternoon shade is ideal.
Watering
- Rhododendron: Requires consistent moisture but dislikes waterlogged conditions. It’s best to keep the soil evenly moist, especially during dry spells. Rhododendrons often prefer slightly acidic soil.
- Hydrangea: Needs regular watering to keep the soil consistently moist, especially during hot, dry periods. Hydrangeas can be sensitive to drought, so they may need more frequent watering compared to Rhododendrons.
Soil
- Rhododendron: Prefers well-draining, acidic soil with a pH typically between 4.5 and 6.0. Adding organic matter can improve soil structure and acidity.
- Hydrangea: Soil preferences vary. Many Hydrangeas thrive in well-draining, organic-rich soil that is slightly acidic to neutral. Soil pH can affect flower color in some varieties (e.g., blue flowers in acidic soil, and pink in alkaline soil).
Fertilizing
- Rhododendron: Benefits from a balanced, acid-loving fertilizer applied in early spring before new growth begins. Avoid over-fertilizing as it can lead to excessive foliage at the expense of blooms.
- Hydrangea: Benefits from regular feeding during the growing season. Use a balanced fertilizer or one specifically formulated for Hydrangeas to encourage blooms. Some varieties may also benefit from fertilizers that alter soil pH to change flower color.
Pruning
- Rhododendron: Prune immediately after flowering to shape the plant and remove any dead or diseased wood. Pruning before or during flowering may remove buds and reduce blooming.
- Hydrangea: Pruning requirements vary by type. Some Hydrangeas bloom on old wood and should be pruned immediately after flowering. Others bloom on new wood and can be pruned in late winter or early spring. Check the specific variety for best practices.
Pests and Diseases
- Rhododendron: Generally low-maintenance with few serious pest issues. However, watch for pests like lace bugs and diseases like powdery mildew or root rot. Good air circulation and proper watering can help prevent problems.
- Hydrangea: Can be susceptible to pests like aphids, spider mites, and scale insects, as well as diseases like powdery mildew and leaf spot. Proper spacing, watering, and regular inspection can help manage these issues.
Winter Care
- Rhododendron: Hardy in most regions but may benefit from mulch around the base to protect roots and retain soil moisture during winter. In very cold climates, some protection from harsh winds may be necessary.
- Hydrangea: Winter care depends on the variety. Some Hydrangeas are hardy and require minimal winter protection, while others might need mulching or covering to protect the base from extreme cold.
Spirea Plants Similar to Hydrangea
Typically a shrub with small, delicate leaves and clusters of tiny, often pink or white flowers. It has a rounded, bushy shape and its foliage turns vibrant colours in fall.
Distinguishing Between Spirea and Hydrangea
- Flowers: Hydrangeas have large, dramatic blooms, while Spireas have smaller, clustered flowers.
- Foliage: Hydrangea leaves are broad and often glossy, whereas Spirea leaves are smaller and maybe more textured. read my other post about identifying plants by their leaf.
- Overall Shape: Spirea tends to be denser and more rounded, while Hydrangeas can be more open and sprawling.
Caring Needs Comparison: Spirea vs. Hydrangea
Sunlight
- Spirea: Thrives in full sun to partial shade. It generally needs at least 4-6 hours of direct sunlight daily for optimal flowering and growth.
- Hydrangea: Preferences vary by species. Many Hydrangeas do well in partial shade, especially in hotter climates, while some varieties can handle full sun. Morning sun with afternoon shade is often ideal.
Watering
- Spirea: Requires regular watering, particularly during dry periods. It is somewhat drought-tolerant once established but performs best with consistent moisture.
- Hydrangea: Needs regular watering to keep the soil consistently moist, especially during hot, dry periods. Hydrangeas are more sensitive to drought and generally need more frequent watering compared to Spirea.
Soil
- Spirea: Adaptable to a range of soil types but prefers well-draining soil. It can tolerate slightly acidic to neutral pH levels.
- Hydrangea: Soil preferences vary. Many Hydrangeas thrive in well-draining, organic-rich soil that is slightly acidic to neutral. Soil pH can affect flower colour in some varieties (e.g., blue flowers in acidic soil, and pink in alkaline soil).
Fertilizing
- Spirea: Benefits from a balanced, general-purpose fertilizer applied in early spring before new growth begins. It typically doesn’t require heavy feeding.
- Hydrangea: Benefits from regular feeding during the growing season. Use a balanced fertilizer or one specifically formulated for Hydrangeas to encourage blooms. Some varieties may also benefit from fertilizers that alter soil pH to change flower color.
Pruning
- Spirea: Generally pruned in late winter or early spring before new growth starts. Deadheading spent flowers can promote additional blooming in some varieties.
- Hydrangea: Pruning requirements vary by type. Some Hydrangeas bloom on old wood and should be pruned immediately after flowering. Others bloom on new wood and can be pruned in late winter or early spring. Check the specific variety for best practices.
Pests and Diseases
- Spirea: Generally resistant to pests and diseases but can occasionally face issues like aphids or leaf spot. Good air circulation and proper watering help prevent problems.
- Hydrangea: Can be susceptible to pests like aphids, spider mites, and scale insects, as well as diseases like powdery mildew and leaf spot. Proper spacing, watering, and regular inspection can help manage these issues.
- Spirea: Generally hardy and requires minimal winter protection. Mulching around the base can help protect roots and maintain soil moisture during winter.
- Hydrangea: Winter care depends on the variety. Some Hydrangeas are hardy and require minimal winter protection, while others might need mulching or covering to protect the base from extreme cold.
Viburnum Plants Similar to Hydrangea
- Leaves: Typically ovate or elliptical, often with a smooth or slightly serrated edge. They can range from dark green to reddish hues in the fall.
- Flowers: Arranged in clusters, can be white, pink, or red, depending on the species. They are usually small but can form large, showy blooms.
- Fruit: Produces berries that can be red, blue, or black, adding colour to the plant in late summer or fall.
- Shape: Generally rounded or irregular, with a dense growth habit.
Distinguishing Between Viburnum and Hydrangea
- Leaves: Viburnum leaves are often more varied in shape and edge, while Hydrangea leaves are usually larger and more consistent.
- Flowers: Viburnum flowers are typically smaller and cluster more densely, whereas Hydrangea flowers form larger, more conspicuous clusters.
- Fruit: Viburnum produces noticeable berries; Hydrangeas have less prominent fruit.
- Shape: Viburnum tends to be denser and more rounded, while Hydrangeas can appear more open and airy.
Compare the Caring Needs of Viburnum with Hydrangea
Sunlight
- Viburnum: Prefers full sun to partial shade. Most species will do well with at least 4-6 hours of direct sunlight each day. Some varieties can tolerate more shade but may have reduced flowering.
- Hydrangea: Light requirements vary by species. Many Hydrangeas prefer partial shade, especially in hotter climates. Morning sun with afternoon shade is often ideal. Some varieties can handle full sun if given enough water.
Watering
- Viburnum: Generally requires regular watering, especially during dry periods. Viburnum is somewhat drought-tolerant once established but benefits from consistent moisture.
- Hydrangea: Needs frequent watering to keep the soil consistently moist, especially during hot and dry periods. Hydrangeas are less tolerant of drought compared to Viburnum and require more consistent moisture.
Soil
- Viburnum: Adaptable to a range of soil types but prefers well-draining soil. It can tolerate slightly acidic to neutral pH levels. Some species are more tolerant of clay or loamy soils.
- Hydrangea: Prefers well-draining, organic-rich soil. The pH of the soil can affect flower color: acidic soils tend to produce blue flowers, while alkaline soils result in pink blooms. Hydrangeas generally need soil that retains moisture but does not become waterlogged.
Fertilizing
- Viburnum: Benefits from a balanced, general-purpose fertilizer applied in early spring. Over-fertilizing can lead to excessive foliage growth at the expense of blooms.
- Hydrangea: Requires regular feeding during the growing season. A balanced fertilizer or one specifically formulated for Hydrangeas can promote blooms. Some varieties benefit from fertilizers that adjust soil pH to influence flower color.
Pruning
- Viburnum: Pruning needs vary by species. Generally, pruning is done in late winter or early spring before new growth begins. Some varieties may also benefit from light summer pruning to maintain shape.
- Hydrangea: Pruning requirements depend on the variety. Some Hydrangeas bloom on old wood and should be pruned immediately after flowering. Others bloom on new wood and can be pruned in late winter or early spring. It’s important to understand the specific pruning needs of the variety you have.
Pests and Diseases
- Viburnum: Generally resistant to pests and diseases, but can occasionally face issues like aphids, scale insects, or fungal diseases such as powdery mildew. Good air circulation and proper watering help prevent many problems.
- Hydrangea: Can be susceptible to pests like aphids, spider mites, and scale insects, as well as diseases such as powdery mildew and leaf spot. Proper spacing, watering, and regular inspection are important for managing these issues.
Winter Care
- Viburnum: Typically hardy and requires minimal winter protection. Mulching around the base can help protect roots and maintain soil moisture during winter.
- Hydrangea: Winter care depends on the species. Some Hydrangeas are hardy and need minimal protection, while others may require mulching or covering to protect the base from extreme cold.
Conclusion
I told you 4 flowering plants Lilac, Rhododendron, Spirea, and Viburnum are so similar to Hydrangea. Although, you can distinguish them by their key features mentioned above. Understanding these differences will help you find out what plant is thriving in your garden and that you are aware of its caring needs.
Hydrangeas and all its lookalikes are popular for their striking floral displays and can add significant visual interest to your gardens and landscapes. However, you must consider their difference before adding them to your garden. for instance, Rhododendron plants have year-round foliage and tend to offer evergreen beauty, while Hydrangeas provide a seasonal display with a range of colours and larger blooms in landscapes.
Elahe Rabiei
Hi, I’m Elaheh. My Academic major is plant protection, and houseplants are my expertise. As a houseplant lover, my house is full of indoor plants and it is my passion to take care of them. Hence, I’m here to share my knowledge and experience about growing healthy houseplants. I am also a plant protection advisor, so feel free to ask me any questions you may have.
inhouseplant2017@gmail.com