Plant Care Guide

Buddleia Butterfly Bush

Buddleja davidii

The Buddleia Butterfly Bush is a fast-growing, sun-loving shrub celebrated for its long, colorful flower spikes that attract butterflies, bees, and hummingbirds from early summer through fall. Known for its resilience, drought tolerance, and ability to bloom continuously, this plant is a favorite in butterfly gardens and pollinator landscapes. Its fragrant, nectar-filled flowers grow in lush plumes; in shades of purple, pink, white, blue, and more depending on the variety. 

While exceptionally low maintenance, Buddleia does require the right drainage, plenty of sun, and annual pruning to maintain its best growth and bloom performance. With the proper care, it becomes a stunning focal point that supports adult pollinators all season long. 

Watering Requirements

Buddleia prefers evenly moist soil while young but becomes increasingly drought tolerant as it matures. Overwatering is the most common issue with this shrub because its roots are highly susceptible to rot, especially if drainage is poor. 

Watering Schedule 

Newly Planted Shrubs: 

  • Water 2–3 times per week during establishment 
  • Ensure soil dries slightly between waterings 

Established Shrubs: 

  • Water only during extended dry spells 
  • Outdoor plants rarely need supplemental watering if rainfall reaches 1 inch/week 

Signs of Overwatering 

  • Yellowing leaves 
  • Wilting despite wet soil 
  • Root rot 
  • Dieback after winter (often from sitting in cold wet soil, not the cold itself) 

Signs of Underwatering 

  • Drooping leaves in heat 
  • Smaller bloom clusters 

Pro Tips

Plant Buddleia “high” (slightly above ground level) to keep water from pooling at the crown, especially critical in clay soil.

Light Requirements

Buddleia thrives in full sun, requiring a minimum of 6–8 hours daily. Too little sun results in fewer blooms and leggy growth. 

Ideal Placement 

  • Open landscapes with direct sun 
  • South- or west-facing exposures 
  • Avoid shaded areas, shade reduces flowering dramatically 

Signs of Inadequate Light 

  • Sparse bloom spires 
  • Weak, elongated stems 
  • Reduced butterfly activity 

Pro Tips

If you want continuous flowers all season long, choose the sunniest spot available. Buddleia will always reward more sun with more blooms.

Soil & Potting

The butterfly bush adapts well to most soils but demands excellent drainage. 

Ideal Soil Conditions 

  • Well-draining sandy or loamy soil 
  • Neutral to slightly acidic pH (6.0–7.0) 
  • Avoid heavy, water-retentive soils 

For Clay Soil 

  • Do not amend the planting hole (causes water pooling) 
  • Plant more shallowly than other shrubs 
  • Avoid heavy mulching around the stems 

Container Growing 

Dwarf varieties do exceptionally well in pots. Use: 

  • Large pots with multiple drainage holes 
  • Lightweight, fast-draining potting mix 
  • Containers made of weatherproof material for outdoor year-round use 

Pro Tips

Never mulch directly against Buddleia’s stems, leave a mulch-free zone to prevent moisture buildup and rot.

Fertilizing

Butterfly bush is not a heavy feeder. Overfeeding promotes leafy growth instead of blooms. 

Fertilizer Schedule 

  • Apply a light layer of compost around the root zone in spring 
  • Fertilize only if soil is poor 
  • Use a balanced, slow-release fertilizer once in early spring 

Signs of Nutrient Deficiency 

  • Poor growth 
  • Pale leaves 
  • Smaller-than-normal flower plumes 

Pro Tips

If your Buddleia is planted in rich garden soil, skip fertilizer entirely. Too much nitrogen can decrease blooms.

Pruning & Maintenance

Pruning is essential for maintaining size, shape, and abundant flowering. 

How to Prune 

  • Prune in early spring once new growth is visible 
  • Cut stems back to 12–24 inches (depending on variety and climate) 
  • Remove damaged or winter-killed wood 

Why Prune? 

  • Encourages vigorous new blooming wood 
  • Prevents plants from becoming tall, bare, and top-heavy 
  • Keeps flower spikes at eye-level 

Deadheading 

  • Remove fading flower clusters promptly 
  • Prevents unwanted self-seeding 
  • Encourages new bloom cycles into fall 

Pro Tips

Be patient in spring. Buddleia is one of the last shrubs to leaf out, don’t assume it’s dead! Many don’t show signs of life until late May or even June.

Common Problems & Solutions

Root Rot 

Cause: Poor drainage 

Fix: Improve soil aeration, reduce watering, plant higher 

Weak, Sparse Blooms 

Cause: Not enough sun or too much nitrogen 

Fix: Increase sunlight exposure; reduce fertilizer 

Spider Mites 

Signs: Speckled leaves, fine webbing 

Fix: Hose down foliage, use horticultural oil if needed 

Aggressive Self-Seeding 

Cause: Allowing seed heads to mature 

Fix: Deadhead promptly; choose sterile cultivars 

Pro Tips

If you want all the butterfly benefits with none of the invasiveness, choose sterile varieties.