Butterfly Bush (Buddleja Davidii ‘Nanho Blue’)

Plant: Table of Contents

Butterfly Bush (Buddleja davidii ‘Nanho Blue’) – A Guide for Cultivation and Care


Butterfly bushes are a popular choice for many gardeners due to their ability to attract butterflies and other pollinators. Among the various cultivars of Buddleja davidii, ‘Nanho Blue’ is particularly favored for its stunning blue-purple flowers and graceful appearance. As a plant scientist, I’m excited to delve into the specifics of the charming butterfly bush, providing a comprehensive guide for its cultivation, care, and maintenance. Let’s explore the key aspects of butterfly bush (Buddleja davidii ‘Nanho Blue’) and understand how to promote its optimal growth and vigor.

What is Butterfly Bush (Buddleja davidii ‘Nanho Blue’)?

The butterfly bush (Buddleja davidii) ‘Nanho Blue’ is a deciduous shrub that belongs to the Scrophulariaceae family. It is renowned for its ability to attract butterflies and hummingbirds, adding a vibrant and lively touch to gardens and landscapes. The ‘Nanho Blue’ cultivar specifically stands out for its striking bluish-lavender flowers, which create a captivating visual display and exude a delightful fragrance. This butterfly bush is generally medium-sized, reaching a height of around 4-6 feet and a spread of 4-6 feet, making it a valuable addition to both small and large gardens. With its adaptability to various growing conditions and relatively low maintenance requirements, ‘Nanho Blue’ has become a beloved choice for gardeners seeking to foster biodiversity and natural beauty.

Key Takeaways – Butterfly Bush (Buddleja davidii ‘Nanho Blue’)

Before delving into the details of the cultivation and care of ‘Nanho Blue’ butterfly bush, let’s outline the key takeaways that encapsulate its significance and appeal:

  • Butterfly-attracting plant: ‘Nanho Blue’ is renowned for its ability to attract butterflies and hummingbirds, contributing to the preservation of these vital pollinators and enhancing the ecological balance of the garden.
  • Low-maintenance cultivar: This cultivar is relatively low-maintenance, making it an ideal choice for gardeners seeking a beautiful and sustainable addition to their landscapes.
  • Fragrant, bluish-lavender blooms: The captivating bluish-lavender flowers of ‘Nanho Blue’ not only add aesthetic charm to the garden but also release a delightful fragrance, enriching the overall sensory experience.
  • Adaptability to various conditions: The ‘Nanho Blue’ butterfly bush demonstrates versatility in its growing requirements, making it suitable for different climate zones and soil types.
  • Contribution to biodiversity: By serving as a nectar source for butterflies and other pollinators, ‘Nanho Blue’ plays a role in promoting biodiversity and ecological health in garden environments.

Now that we’ve established the significance of ‘Nanho Blue’ butterfly bush, let’s embark on a detailed exploration of its cultivation and care to enable gardeners to nurture this beautiful shrub successfully.


Cultivating the ‘Nanho Blue’ butterfly bush involves understanding its cultural needs, including water, sunlight, soil, and fertilization.


  • The butterfly bush generally prefers well-draining soil and moderate moisture levels. While it is tolerant of occasional dry periods, consistent watering, especially during the establishment phase, is essential for promoting healthy growth and flowering.
  • It is important to avoid waterlogged conditions, as excessive moisture can lead to root rot and other detrimental effects on the plant’s health.
  • During periods of drought, supplemental watering may be necessary, particularly for newly planted specimens or those grown in containers.


  • ‘Nanho Blue’ butterfly bush thrives in full sun, requiring at least 6-8 hours of direct sunlight daily for optimal growth and prolific flowering.
  • Ensuring adequate sunlight exposure is crucial for promoting the development of abundant and vibrant flower clusters, which are essential for attracting butterflies and other pollinators.


  • Incorporating a balanced, slow-release fertilizer into the soil in early spring can provide the necessary nutrients for the butterfly bush to thrive throughout the growing season.
  • It is advisable to use a fertilizer specifically formulated for flowering shrubs to support healthy blooming and overall vigor.
  • Care should be taken to follow the recommended application rates to prevent over-fertilization, which can negatively impact the plant’s health and flowering performance.


  • Butterfly bushes, including ‘Nanho Blue,’ prefer well-drained soil with a slightly acidic to neutral pH range (pH 6.0-7.0).
  • Amending the soil with organic matter, such as compost or well-rotted manure, can improve its structure, moisture retention, and nutrient content, contributing to the overall health of the plant.
  • While butterfly bushes are adaptable to various soil types, excessive clay content or poor drainage should be addressed through soil improvement measures to prevent waterlogging and root stress.


Pruning is a critical aspect of butterfly bush maintenance, influencing the plant’s growth habits, flowering performance, and overall appearance.

Pruning Timing

  • Pruning should be carried out in late winter or early spring before new growth emerges. This timing allows for the removal of dead or damaged wood and the shaping of the plant’s structure without compromising the development of new shoots and flower buds.
  • Late winter pruning also facilitates the removal of spent flower clusters from the previous season, promoting a tidy and rejuvenated appearance for the upcoming growing season.

Pruning Techniques

  • When pruning ‘Nanho Blue’ butterfly bush, it is important to remove any dead, diseased, or crossing branches to maintain good air circulation and reduce the risk of fungal diseases.
  • To encourage a more compact and bushy growth habit, the plant can be selectively pruned to promote lateral branching and discourage leggy growth.
  • Deadheading spent flowers throughout the blooming season can prolong the flowering period and prevent the formation of seedheads, redirecting the plant’s energy into continued blooming and vegetative growth.

Size Management

  • Regular pruning can help manage the size of the butterfly bush, especially for gardeners with limited space or those growing the plant in containers.
  • By selectively removing older stems and shaping the plant to the desired size and form, it is possible to maintain a tidy and manageable growth habit while promoting flowering at eye level for enhanced visual impact.

Cautionary Note

  • While pruning is essential for maintaining the health and vigor of the butterfly bush, excessive and untimely pruning can limit its flowering potential and disrupt the natural shape of the plant. It is important to exercise caution and follow proper pruning guidelines to ensure the plant’s well-being.


Propagating butterfly bushes, including the ‘Nanho Blue’ cultivar, allows for the multiplication of desirable traits and the expansion of one’s garden collection. Several methods can be utilized for propagating butterfly bushes, providing options for gardeners to propagate their favorite cultivars or share plants with fellow enthusiasts.

Propagation Methods

  1. Softwood Cuttings: Softwood cuttings can be taken in early summer when the plant’s new growth is still tender and flexible. By selecting healthy, non-flowering shoots and preparing them for propagation, gardeners can root the cuttings in a well-draining medium and provide the necessary warmth and moisture for successful establishment.

  2. Hardwood Cuttings: Hardwood cuttings are typically collected in late autumn or early winter when the plant is dormant. These cuttings, consisting of mature, woody stems, can be prepared and inserted into a propagation medium for root development over the winter months, eventually yielding new plants in the following growing season.

  3. Division: Butterfly bushes can also be propagated through division, particularly for established clumps that have developed multiple stems or offshoots. Dividing the root mass and separating individual sections allows for the creation of new plants, each with its own set of roots and growing points.

Factors for Success

  • Selecting healthy and disease-free parent plants for propagation is crucial to ensuring the vigor and quality of the resulting offspring.
  • Providing the appropriate environmental conditions, including humidity, warmth, and protection from direct sunlight, can promote successful rooting and establishment of propagated cuttings or divisions.
  • Regular monitoring and care, such as maintaining consistent moisture levels and protecting newly propagated specimens from stress, contribute to the overall success of the propagation process.

Container Popularity

The ‘Nanho Blue’ butterfly bush holds particular appeal for container gardening enthusiasts, offering a compact and ornamental option for adding color and biodiversity to outdoor spaces.

  • Space Efficiency: The medium size of ‘Nanho Blue’ makes it well-suited for container growth, allowing individuals with limited garden space to enjoy the beauty and benefits of a butterfly-attracting plant.
  • Portability: Containers provide the flexibility to relocate the butterfly bush to optimal sunlight conditions or protected areas during challenging weather, contributing to the plant’s well-being and longevity.
  • Decorative Accent: Placing ‘Nanho Blue’ in a container allows for creative placement in gardens, patios, and balconies, enhancing the visual appeal of outdoor living spaces with its vibrant flowers and wildlife-attracting qualities.

Common Diseases

While the ‘Nanho Blue’ butterfly bush is generally resilient, it is susceptible to certain diseases that can affect its health and vitality.

Disease Diagnosis

  1. Powdery Mildew: Powdery mildew, characterized by a white, powdery coating on the plant’s leaves, is a common issue for butterfly bushes, particularly in humid or poorly ventilated conditions. Diagnosing powdery mildew involves inspecting the foliage for signs of powdery growth and addressing contributing factors, such as high humidity and overcrowding, to prevent its recurrence.

  2. Leaf Spot: Leaf spot diseases manifest as dark, circular lesions on the plant’s leaves, potentially leading to defoliation and reduced vigor. Identifying leaf spot involves monitoring the appearance and spread of lesions, implementing cultural practices to reduce leaf wetness, and considering targeted fungicidal treatments if necessary.

  3. Root Rot: Root rot, caused by waterlogging and soilborne pathogens, can adversely affect the root system of butterfly bushes, leading to wilting, yellowing foliage, and overall decline. Detecting root rot involves carefully examining the plant’s roots for discoloration, mushy texture, and noticeable decay, requiring corrective measures such as improving soil drainage and avoiding excessive irrigation.

Disease Management

  • Cultural Practices: Ensuring adequate spacing between plants, promoting proper air circulation, and avoiding overhead watering can mitigate the risk of foliar diseases and prevent their spread.
  • Soil Improvement: Amending the soil with organic matter and ensuring good drainage contributes to the overall health and resilience of the butterfly bush, reducing the likelihood of root diseases such as root rot.
  • Pruning: Regular pruning to remove diseased or damaged plant parts helps maintain the overall vigor and vitality of the butterfly bush, limiting the impact of diseases on its growth.

Common Pests

In addition to diseases, butterfly bushes, including ‘Nanho Blue,’ can be targeted by certain pest species that may compromise their health and flowering performance.

Pest Identification

  1. Aphids: Aphids are common sap-sucking insects that can infest the tender shoots and flower clusters of butterfly bushes, causing distortion of new growth and the development of sticky honeydew. Identifying aphid infestations involves inspecting the plant for clusters of small, soft-bodied insects and their associated feeding damage.

  2. Spider Mites: Spider mites, characterized by their tiny size and webbing on the undersides of leaves, can affect the foliage of butterfly bushes, leading to stippling, discoloration, and overall decline. Monitoring the plant for signs of webbing, stippled leaves, and decreased vigor aids in early detection of spider mite infestations.

  3. Caterpillars: Certain caterpillar species may feed on the foliage of butterfly bushes, potentially causing defoliation and aesthetic damage. Observing the presence of caterpillars and their feeding patterns assists in identifying and managing their impact on the plant’s health.

Pest Control

  • Mechanical Control: Techniques such as spraying plants with a strong stream of water or manually removing pests, such as aphids and caterpillars, can help reduce pest populations without the use of chemical controls.
  • Horticultural Oils: Applying horticultural oils to the plant’s foliage can effectively manage spider mite infestations by suffocating the pests and disrupting their reproductive cycles, contributing to pest control while minimizing environmental impact.
  • Integrated Pest Management (IPM): Employing a holistic approach to pest management that integrates cultural practices, biological controls, and targeted treatments allows for effective pest control while minimizing the reliance on chemical pesticides.

Botanist’s Tips

As a plant scientist, I’d like to offer some valuable insights and tips for successfully cultivating and caring for the ‘Nanho Blue’ butterfly bush, promoting its health, attractiveness to pollinators, and long-term sustainability in garden environments.

Promoting Butterfly Attraction

  • In addition to planting ‘Nanho Blue’ butterfly bush, incorporating a diverse selection of nectar-rich flowering plants in the garden can enhance its overall appeal to butterflies, providing varied food sources and shelter for these important pollinators.
  • Including native plants and regionally suitable species in the garden further contributes to fostering a supportive habitat for butterflies, aligning with their natural preferences and ecological requirements.

Enhancing Soil Health

  • Conducting soil tests to assess the pH, nutrient levels, and overall quality of the soil provides valuable insights for adjusting soil conditions to meet the specific needs of the butterfly bush and promote its robust growth and flowering.
  • Amending the soil with organic matter, such as compost, leaf mulch, or well-rotted manure, supports microbial activity and nutrient availability, creating a favorable environment for the plant’s root development and overall vitality.

Supporting Pollinator Diversity

  • Creating a layered and diverse garden structure with a mix of flowering shrubs, perennials, and annuals provides varied foraging opportunities for butterflies and other pollinators, enriching the garden’s biodiversity and ecological resilience.
  • Incorporating plants with different bloom times extends the availability of nectar and pollen resources, addressing the needs of pollinators throughout the growing season and promoting their sustained presence in the garden.

Environmental Stewardship

  • Embracing sustainable gardening practices, such as water conservation, organic pest management, and minimal use of synthetic fertilizers, aligns with the principles of environmental stewardship and contributes to the long-term health and productivity of garden ecosystems.
  • Engaging in responsible plant care and maintenance, including proper disposal of diseased plant materials and conscientious use of resources, supports a balanced and harmonious relationship with nature within the garden environment.

Fun Facts

  • The butterfly bush (Buddleja davidii) is native to China and was introduced to the Western horticultural scene due to its remarkable ability to attract butterflies, earning it the common name “butterfly bush.”
  • ‘Nanho Blue’ is a cultivar of Buddleja davidii, distinguished by its elegant, elongated clusters of bluish-lavender flowers and its strong appeal to various butterfly species, such as swallowtails, painted ladies, and monarchs.
  • The fragrance of ‘Nanho Blue’ flowers is particularly alluring, often described as sweet and honey-like, creating an enchanting ambiance in the garden and drawing attention from human observers and pollinating insects alike.

Links to External Resources

For further information on butterfly bushes, native butterfly plants, attracting butterflies to the garden, and related topics, the following external resources provide valuable insights and guidance:

Butterfly Plants and Gardening

  1. National Wildlife Federation – Attracting Butterflies
  2. The Xerces Society – Pollinator Conservation Resources
  3. Butterfly Conservation – Gardening for Butterflies

Buddleja Davidii Cultivation and Care

  1. Royal Horticultural Society – Buddleja davidii
  2. Missouri Botanical Garden – Buddleja davidii

Gardening and Plant Health

  1. Cooperative Extension System – Gardening Resources
  2. American Horticultural Society – Plant Health Care

Native Plants and Biodiversity

  1. Lady Bird Johnson Wildflower Center – Native Plant Information
  2. The National Audubon Society – Native Plants Database

Butterfly Conservation and Ecology

  1. Butterflies and Moths of North America – Butterfly Gardening
  2. The Butterfly Site – Butterfly Information and Resources


The ‘Nanho Blue’ butterfly bush (Buddleja davidii ‘Nanho Blue’) stands as a captivating and ecologically valuable addition to garden landscapes, contributing to the attraction of butterflies, the promotion of biodiversity, and the creation of aesthetically pleasing garden environments. By understanding and implementing the key cultural practices, disease and pest management strategies, and thoughtful insights provided in this guide, gardeners can nurture the ‘Nanho Blue’ butterfly bush with confidence and success, reaping the rewards of its vibrant blooms, delightful fragrance, and positive impact on pollinator conservation.

As we continue to appreciate and support the natural world around us, the cultivation of butterfly-attracting plants such as ‘Nanho Blue’ serves as a testament to our dedication to environmental stewardship, biodiversity conservation, and the creation of harmonious garden spaces that delight and inspire both humans and wildlife. Let’s embrace the beauty and ecological significance of butterfly bushes, fostering a shared admiration for these enchanting plants and the pollinators they so gracefully attract.

The blog post provides an in-depth exploration of the ‘Nanho Blue’ butterfly bush, encompassing its cultural needs, maintenance guidelines, pest and disease management, propagation methods, and valuable insights for successful cultivation. Additionally, it offers engaging fun facts and external resources to further enrich the reader’s understanding of butterfly-attracting plants and their significance in ecological conservation and garden stewardship.

Picture of Peter Taylors

Peter Taylors

Expert botanist who loves plants. His expertise spans taxonomy, plant ecology, and ethnobotany. An advocate for plant conservation, he mentors and educates future botanists, leaving a lasting impact on the field.